Merge pull request #3814 from zmstone/umbrella-fix-build

Umbrella fix build

.github/workflows/run_test_case.yaml

@@ -7,10 +7,10 @@ jobs:
     run_test_case:
 
         runs-on: ubuntu-latest
-      
+
         container:
             image: erlang:22.1
-      
+
         steps:
         - uses: actions/checkout@v1
         - name: Code dialyzer

Makefile

@@ -2,7 +2,7 @@ REBAR_VERSION = 3.14.3-emqx-2
 REBAR = ./rebar3
 
 PROFILE ?= emqx
-PROFILES := emqx emqx-edge
+PROFILES := emqx emqx-edge check test
 PKG_PROFILES := emqx-pkg emqx-edge-pkg
 
 export REBAR_GIT_CLONE_OPTIONS += --depth=1
@@ -38,14 +38,10 @@ $(PROFILES:%=build-%): $(REBAR)
 
 # rebar clean
 .PHONY: clean $(PROFILES:%=clean-%)
-clean: $(PROFILES:%=clean-%) clean-stamps
+clean: $(PROFILES:%=clean-%)
 $(PROFILES:%=clean-%): $(REBAR)
 	$(REBAR) as $(@:clean-%=%) clean
 
-.PHONY: clean-stamps
-clean-stamps:
-	find -L _build -name '.stamp' -type f | xargs rm -f
-
 .PHONY: deps-all
 deps-all: $(REBAR) $(PROFILES:%=deps-%) $(PKG_PROFILES:%=deps-%)
 

apps/emqx_auth_http/src/emqx_auth_http.erl

@@ -29,6 +29,10 @@
         , feedvar/2
         ]).
 
+-type http_request() :: #http_request{method::'get' | 'post',params::[any()]}.
+%-type http_opts() :: #{clientid:=_, peerhost:=_, protocol:=_, _=>_}.
+%-type retry_opts() :: #{backoff:=_, interval:=_, times:=_, _=>_}.
+
 %% Callbacks
 -export([ register_metrics/0
         , check/3
@@ -80,7 +84,7 @@ authenticate(PoolName, #http_request{path = Path,
                                      request_timeout = RequestTimeout}, ClientInfo) ->
    request(PoolName, Method, Path, Headers, feedvar(Params, ClientInfo), RequestTimeout).
 
--spec(is_superuser(atom(), maybe(#http_request{}), emqx_types:client()) -> boolean()).
+-spec(is_superuser(atom(), maybe(http_request()), emqx_types:client()) -> boolean()).
 is_superuser(_PoolName, undefined, _ClientInfo) ->
     false;
 is_superuser(PoolName, #http_request{path = Path,

apps/emqx_auth_http/src/emqx_auth_http_app.erl

@@ -36,8 +36,8 @@ start(_StartType, _StartArgs) ->
         ok ->
             {ok, PoolOpts} = application:get_env(?APP, pool_opts),
             {ok, Sup} = emqx_http_client_sup:start_link(?APP, ssl(inet(PoolOpts))),
-            with_env(auth_req, fun load_auth_hook/1),
-            with_env(acl_req,  fun load_acl_hook/1),
+            _ = with_env(auth_req, fun load_auth_hook/1),
+            _ = with_env(acl_req,  fun load_acl_hook/1),
             {ok, Sup};
         {error, Reason} ->
             {error, Reason}
@@ -157,4 +157,4 @@ get_addr(Hostname) ->
                      Addr;
                  {ok, Addr} -> Addr
             end
-    end.
+    end.

apps/emqx_auth_jwt/src/emqx_auth_jwt_app.erl

@@ -33,11 +33,10 @@ start(_Type, _Args) ->
 
     {ok, Pid} = start_auth_server(jwks_svr_options()),
     ok = emqx_auth_jwt:register_metrics(),
-
     AuthEnv0 = auth_env(),
     AuthEnv1 = AuthEnv0#{pid => Pid},
 
-    emqx:hook('client.authenticate', {emqx_auth_jwt, check, [AuthEnv1]}),
+    _ = emqx:hook('client.authenticate', {emqx_auth_jwt, check, [AuthEnv1]}),
     {ok, Sup, AuthEnv1}.
 
 stop(AuthEnv) ->

apps/emqx_auth_jwt/src/emqx_auth_jwt_svr.erl

@@ -176,7 +176,7 @@ reset_timer(State = #state{intv = Intv}) ->
 cancel_timer(State = #state{tref = undefined}) ->
     State;
 cancel_timer(State = #state{tref = TRef}) ->
-    erlang:cancel_timer(TRef),
+    _ = erlang:cancel_timer(TRef),
     State#state{tref = undefined}.
 
 do_verify(_JwsCompated, []) ->

apps/emqx_auth_ldap/src/emqx_auth_ldap_app.erl

@@ -30,11 +30,11 @@
 
 start(_StartType, _StartArgs) ->
     {ok, Sup} = emqx_auth_ldap_sup:start_link(),
-    if_enabled([device_dn, match_objectclass,
+    _ = if_enabled([device_dn, match_objectclass,
                 username_attr, password_attr,
                 filters, custom_base_dn, bind_as_user],
                fun load_auth_hook/1),
-    if_enabled([device_dn, match_objectclass,
+    _ = if_enabled([device_dn, match_objectclass,
                 username_attr, password_attr,
                 filters, custom_base_dn, bind_as_user],
                fun load_acl_hook/1),
@@ -60,8 +60,7 @@ load_acl_hook(DeviceDn) ->
 
 if_enabled(Cfgs, Fun) ->
     case get_env(Cfgs) of
-        {ok, InitArgs} -> Fun(InitArgs);
-        [] -> ok
+        {ok, InitArgs} -> Fun(InitArgs)
     end.
 
 get_env(Cfgs) ->

apps/emqx_auth_mnesia/src/emqx_acl_mnesia_api.erl

@@ -151,7 +151,7 @@ do_add(Params) ->
     Action = urldecode(get_value(<<"action">>, Params)),
     Access = urldecode(get_value(<<"access">>, Params)),
     Re = case validate([login, topic, action, access], [Login, Topic, Action, Access]) of
-        ok -> 
+        ok ->
             emqx_acl_mnesia_cli:add_acl(Login, Topic, erlang:binary_to_atom(Action, utf8), erlang:binary_to_atom(Access, utf8));
         Err -> Err
     end,
@@ -163,7 +163,7 @@ do_add(Params) ->
                      all -> #{all => '$all'};
                      _ -> maps:from_list([Login])
                    end).
-    
+
 delete(#{clientid := Clientid, topic := Topic}, _) ->
     return(emqx_acl_mnesia_cli:remove_acl({clientid, urldecode(Clientid)}, urldecode(Topic)));
 delete(#{username := Username, topic := Topic}, _) ->
@@ -202,12 +202,6 @@ do_validation(login, {clientid, V}) when is_binary(V)
 do_validation(login, {username, V}) when is_binary(V)
                      andalso byte_size(V) > 0->
     true;
-do_validation(clientid, V) when is_binary(V)
-                     andalso byte_size(V) > 0 ->
-    true;
-do_validation(username, V) when is_binary(V)
-                     andalso byte_size(V) > 0 ->
-    true;
 do_validation(topic, V) when is_binary(V)
                      andalso byte_size(V) > 0 ->
     true;

apps/emqx_auth_mnesia/src/emqx_auth_mnesia.erl

@@ -37,9 +37,9 @@ init(#{clientid_list := ClientidList, username_list := UsernameList}) ->
             {disc_copies, [node()]},
             {attributes, record_info(fields, emqx_user)},
             {storage_properties, [{ets, [{read_concurrency, true}]}]}]),
-    [ add_default_user({{clientid, iolist_to_binary(Clientid)}, iolist_to_binary(Password)})
+    _ = [ add_default_user({{clientid, iolist_to_binary(Clientid)}, iolist_to_binary(Password)})
       || {Clientid, Password} <- ClientidList],
-    [ add_default_user({{username, iolist_to_binary(Username)}, iolist_to_binary(Password)})
+    _ = [ add_default_user({{username, iolist_to_binary(Username)}, iolist_to_binary(Password)})
       || {Username, Password} <- UsernameList],
     ok = ekka_mnesia:copy_table(emqx_user, disc_copies).
 
@@ -59,7 +59,7 @@ check(ClientInfo = #{ clientid := Clientid
                               ({?TABLE, {username, X }, Password, InterTime}) when X =:= Username andalso X =/= undefined -> Password
                            end),
     case ets:select(?TABLE, MatchSpec) of
-        [] -> 
+        [] ->
             emqx_metrics:inc(?AUTH_METRICS(ignore)),
             ok;
         List ->

apps/emqx_auth_mnesia/src/emqx_auth_mnesia_api.erl

@@ -145,7 +145,7 @@ do_add_clientid(Params) ->
     Password = urldecode(get_value(<<"password">>, Params)),
     Login = {clientid, Clientid},
     case validate([login, password], [Login, Password]) of
-        ok -> 
+        ok ->
             emqx_auth_mnesia_cli:add_user(Login, Password);
         Err -> Err
     end.
@@ -221,7 +221,9 @@ paginate(Tables, MatchSpec, Params, ComparingFun, RowFun) ->
     Limit = limit(Params),
     Cursor = qlc:cursor(Qh),
     case Page > 1 of
-        true  -> qlc:next_answers(Cursor, (Page - 1) * Limit);
+        true  ->
+            _ = qlc:next_answers(Cursor, (Page - 1) * Limit),
+            ok;
         false -> ok
     end,
     Rows = qlc:next_answers(Cursor, Limit),
@@ -263,14 +265,6 @@ limit(Params) ->
 %% Interval Funcs
 %%------------------------------------------------------------------------------
 
-format({?TABLE, {clientid, ClientId}, Password, _InterTime}) ->
-    #{clientid => ClientId,
-      password => Password};
-
-format({?TABLE, {username, Username}, Password, _InterTime}) ->
-    #{username => Username,
-      password => Password};
-
 format([{?TABLE, {clientid, ClientId}, Password, _InterTime}]) ->
     #{clientid => ClientId,
       password => Password};

apps/emqx_auth_mnesia/src/emqx_auth_mnesia_app.erl

@@ -38,8 +38,8 @@ start(_StartType, _StartArgs) ->
     emqx_ctl:register_command(username, {emqx_auth_mnesia_cli, auth_username_cli}, []),
     emqx_ctl:register_command(user, {emqx_auth_mnesia_cli, auth_username_cli}, []),
     emqx_ctl:register_command(acl, {emqx_acl_mnesia_cli, cli}, []),
-    load_auth_hook(),
-    load_acl_hook(),
+    _ = load_auth_hook(),
+    _ = load_acl_hook(),
     {ok, Sup}.
 
 prep_stop(State) ->

apps/emqx_auth_mnesia/src/emqx_auth_mnesia_cli.erl

@@ -68,13 +68,8 @@ do_update_user(User = #emqx_user{login = Login}) ->
 -spec(lookup_user(tuple()) -> list()).
 lookup_user(undefined) -> [];
 lookup_user(Login) ->
-    case mnesia:dirty_read(?TABLE, Login) of
-        {error, Reason} ->
-            ?LOG(error, "[Mnesia] do_check_user error: ~p~n", [Reason]),
-            [];
-        Re ->
-            lists:sort(fun comparing/2, Re)
-    end.
+    Re = mnesia:dirty_read(?TABLE, Login),
+    lists:sort(fun comparing/2, Re).
 
 %% @doc Remove user
 -spec(remove_user(tuple()) -> ok | {error, any()}).
@@ -88,7 +83,6 @@ all_users() -> mnesia:dirty_all_keys(?TABLE).
 all_users(clientid) ->
     MatchSpec = ets:fun2ms(fun({?TABLE, {clientid, Clientid}, Password, CreatedAt}) -> {?TABLE, {clientid, Clientid}, Password, CreatedAt} end),
     lists:sort(fun comparing/2, ets:select(?TABLE, MatchSpec));
-
 all_users(username) ->
     MatchSpec = ets:fun2ms(fun({?TABLE, {username, Username}, Password, CreatedAt}) -> {?TABLE, {username, Username}, Password, CreatedAt} end),
     lists:sort(fun comparing/2, ets:select(?TABLE, MatchSpec)).
@@ -167,7 +161,6 @@ auth_username_cli(["update", Username, NewPassword]) ->
         ok -> emqx_ctl:print("ok~n");
         {error, Reason} -> emqx_ctl:print("Error: ~p~n", [Reason])
     end;
-
 auth_username_cli(["del", Username]) ->
     case  remove_user({username, iolist_to_binary(Username)}) of
         ok -> emqx_ctl:print("ok~n");

apps/emqx_auth_mongo/src/emqx_auth_mongo.erl

@@ -82,8 +82,6 @@ description() -> "Authentication with MongoDB".
 %%--------------------------------------------------------------------
 %% Is Superuser?
 %%--------------------------------------------------------------------
-
--spec(is_superuser(string(), maybe(#superquery{}), emqx_types:clientinfo()) -> boolean()).
 is_superuser(_Pool, undefined, _ClientInfo) ->
     false;
 is_superuser(Pool, #superquery{collection = Coll, field = Field, selector = Selector}, ClientInfo) ->

apps/emqx_auth_mysql/src/emqx_auth_mysql_app.erl

@@ -36,8 +36,8 @@
 
 start(_StartType, _StartArgs) ->
     {ok, Sup} = emqx_auth_mysql_sup:start_link(),
-    if_enabled(auth_query, fun load_auth_hook/1),
-    if_enabled(acl_query,  fun load_acl_hook/1),
+    _ = if_enabled(auth_query, fun load_auth_hook/1),
+    _ = if_enabled(acl_query,  fun load_acl_hook/1),
 
     {ok, Sup}.
 

apps/emqx_auth_pgsql/src/emqx_auth_pgsql_cli.erl

@@ -29,6 +29,8 @@
         , equery/3
         ]).
 
+-type client_info() :: #{username:=_, clientid:=_, peerhost:=_, _=>_}.
+
 %%--------------------------------------------------------------------
 %% Avoid SQL Injection: Parse SQL to Parameter Query.
 %%--------------------------------------------------------------------
@@ -62,9 +64,6 @@ connect(Opts) ->
         {ok, C} ->
             conn_post(C),
             {ok, C};
-        {error, Reason = econnrefused} ->
-            ?LOG(error, "[Postgres] Can't connect to Postgres server: Connection refused."),
-            {error, Reason};
         {error, Reason = invalid_authorization_specification} ->
             ?LOG(error, "[Postgres] Can't connect to Postgres server: Invalid authorization specification."),
             {error, Reason};
@@ -104,9 +103,11 @@ conn_opts([Opt = {ssl_opts, _}|Opts], Acc) ->
 conn_opts([_Opt|Opts], Acc) ->
     conn_opts(Opts, Acc).
 
+-spec(equery(atom(), string() | epgsql:statement(), Parameters::[any()]) -> {ok, ColumnsDescription :: [any()], RowsValues :: [any()]} | {error, any()} ).
 equery(Pool, Sql, Params) ->
     ecpool:with_client(Pool, fun(C) -> epgsql:prepared_query(C, Sql, Params) end).
 
+-spec(equery(atom(), string() | epgsql:statement(), Parameters::[any()], client_info()) ->  {ok, ColumnsDescription :: [any()], RowsValues :: [any()]} | {error, any()} ).
 equery(Pool, Sql, Params, ClientInfo) ->
     ecpool:with_client(Pool, fun(C) -> epgsql:prepared_query(C, Sql, replvar(Params, ClientInfo)) end).
 

apps/emqx_auth_redis/src/emqx_auth_redis_app.erl

@@ -28,8 +28,8 @@
 
 start(_StartType, _StartArgs) ->
     {ok, Sup} = emqx_auth_redis_sup:start_link(),
-    if_cmd_enabled(auth_cmd, fun load_auth_hook/1),
-    if_cmd_enabled(acl_cmd,  fun load_acl_hook/1),
+    _ = if_cmd_enabled(auth_cmd, fun load_auth_hook/1),
+    _ = if_cmd_enabled(acl_cmd,  fun load_acl_hook/1),
     {ok, Sup}.
 
 stop(_State) ->

apps/emqx_auth_redis/src/emqx_auth_redis_cli.erl

@@ -38,7 +38,7 @@ connect(Opts) ->
     Host = case Sentinel =:= "" of
         true -> get_value(host, Opts);
         false ->
-            eredis_sentinel:start_link(get_value(servers, Opts)),
+            _ = eredis_sentinel:start_link(get_value(servers, Opts)),
             "sentinel:" ++ Sentinel
     end,
     case eredis:start_link(Host,

apps/emqx_bridge_mqtt/src/emqx_bridge_mqtt.erl

@@ -186,6 +186,5 @@ replvar([Key|More], Options) ->
 
 %% ${node} => node()
 feedvar(clientid, ClientId, _) ->
-    iolist_to_binary(re:replace(ClientId, "\\${node}", atom_to_list(node())));
-feedvar(_, Val, _) ->
-    Val.
+    iolist_to_binary(re:replace(ClientId, "\\${node}", atom_to_list(node()))).
+

apps/emqx_bridge_mqtt/src/emqx_bridge_mqtt_cli.erl

@@ -56,16 +56,12 @@ cli(["forwards", Name]) ->
             end, emqx_bridge_worker:get_forwards(Name));
 
 cli(["add-forward", Name, Topic]) ->
-    case emqx_bridge_worker:ensure_forward_present(Name, iolist_to_binary(Topic)) of
-        ok -> emqx_ctl:print("Add-forward topic successfully.~n");
-        {error, Reason} -> emqx_ctl:print("Add-forward failed reason: ~p.~n", [Reason])
-    end;
+    ok = emqx_bridge_worker:ensure_forward_present(Name, iolist_to_binary(Topic)),
+    emqx_ctl:print("Add-forward topic successfully.~n");
 
 cli(["del-forward", Name, Topic]) ->
-    case emqx_bridge_worker:ensure_forward_absent(Name, iolist_to_binary(Topic)) of
-        ok -> emqx_ctl:print("Del-forward topic successfully.~n");
-        {error, Reason} -> emqx_ctl:print("Del-forward failed reason: ~p.~n", [Reason])
-    end;
+    ok = emqx_bridge_worker:ensure_forward_absent(Name, iolist_to_binary(Topic)),
+    emqx_ctl:print("Del-forward topic successfully.~n");
 
 cli(["subscriptions", Name]) ->
     foreach(fun({Topic, Qos}) ->
@@ -79,10 +75,8 @@ cli(["add-subscription", Name, Topic, Qos]) ->
     end;
 
 cli(["del-subscription", Name, Topic]) ->
-    case emqx_bridge_worker:ensure_subscription_absent(Name, Topic) of
-        ok -> emqx_ctl:print("Del-subscription topic successfully.~n");
-        {error, Reason} -> emqx_ctl:print("Del-subscription failed reason: ~p.~n", [Reason])
-    end;
+    ok = emqx_bridge_worker:ensure_subscription_absent(Name, Topic),
+    emqx_ctl:print("Del-subscription topic successfully.~n");
 
 cli(_) ->
     emqx_ctl:usage([{"bridges list",           "List bridges"},

apps/emqx_bridge_mqtt/src/emqx_bridge_rpc.erl

@@ -33,6 +33,7 @@
 
 -type ack_ref() :: emqx_bridge_worker:ack_ref().
 -type batch() :: emqx_bridge_worker:batch().
+-type node_or_tuple() :: atom() | {atom(), term()}.
 
 -define(HEARTBEAT_INTERVAL, timer:seconds(1)).
 
@@ -61,7 +62,7 @@ stop(#{client_pid := Pid}) when is_pid(Pid) ->
     ok.
 
 %% @doc Callback for `emqx_bridge_connect' behaviour
--spec send(node(), batch()) -> {ok, ack_ref()} | {error, any()}.
+-spec send(#{address:=node_or_tuple(), _=>_}, batch()) -> {ok, ack_ref()} | {error, any()}.
 send(#{address := Remote}, Batch) ->
     case ?RPC:call(Remote, ?MODULE, handle_send, [Batch]) of
         ok ->

apps/emqx_bridge_mqtt/src/emqx_bridge_worker.erl

@@ -307,7 +307,7 @@ idle({call, From}, ensure_started, State) ->
     case do_connect(State) of
         {ok, State1} ->
             {next_state, connected, State1, [{reply, From, ok}, {state_timeout, 0, connected}]};
-        {error, Reason} ->
+        {error, Reason, _State} ->
             {keep_state_and_data, [{reply, From, {error, Reason}}]}
     end;
 %% @doc Standing by for manual start.
@@ -320,12 +320,8 @@ idle(state_timeout, reconnect, State) ->
     connecting(State);
 
 idle(info, {batch_ack, Ref}, State) ->
-    case do_ack(State, Ref) of
-        {ok, NewState} ->
-            {keep_state, NewState};
-        _ ->
-            keep_state_and_data
-    end;
+    {ok, NewState} = do_ack(State, Ref),
+    {keep_state, NewState};
 
 idle(Type, Content, State) ->
     common(idle, Type, Content, State).
@@ -359,12 +355,8 @@ connected(info, {disconnected, Conn, Reason},
             keep_state_and_data
     end;
 connected(info, {batch_ack, Ref}, State) ->
-    case do_ack(State, Ref) of
-        {ok, NewState} ->
-            {keep_state, NewState, {next_event, internal, maybe_send}};
-        _ ->
-            keep_state_and_data
-    end;
+    {ok, NewState} = do_ack(State, Ref),
+    {keep_state, NewState, {next_event, internal, maybe_send}};
 connected(Type, Content, State) ->
     common(connected, Type, Content, State).
 

apps/emqx_coap/rebar.config

@@ -1,6 +1,6 @@
 {deps,
  [
-  {gen_coap, {git, "https://github.com/emqx/gen_coap", {tag, "v0.3.0"}}}
+  {gen_coap, {git, "https://github.com/emqx/gen_coap", {tag, "v0.3.1"}}}
  ]}.
 
 {edoc_opts, [{preprocess, true}]}.

apps/emqx_coap/src/emqx_coap_app.erl

@@ -30,7 +30,7 @@ start(_Type, _Args) ->
     {ok, Sup} = emqx_coap_sup:start_link(),
     coap_server_registry:add_handler([<<"mqtt">>], emqx_coap_resource, undefined),
     coap_server_registry:add_handler([<<"ps">>], emqx_coap_ps_resource, undefined),
-    emqx_coap_ps_topics:start_link(),
+    _ = emqx_coap_ps_topics:start_link(),
     emqx_coap_server:start(application:get_all_env(?APP)),
     {ok,Sup}.
 

apps/emqx_coap/src/emqx_coap_mqtt_adapter.erl

@@ -136,7 +136,7 @@ handle_call({unsubscribe, Topic, _CoapPid}, _From, State=#state{sub_topics = Top
     {reply, ok, State#state{sub_topics = NewTopics}, hibernate};
 
 handle_call({publish, Topic, Payload}, _From, State) ->
-    chann_publish(Topic, Payload, State),
+    _ = chann_publish(Topic, Payload, State),
     {reply, ok, State};
 
 handle_call(info, _From, State) ->
@@ -233,10 +233,6 @@ do_deliver({Topic, Payload}, Subscribers) ->
     %% handle PUBLISH packet from broker
     ?LOG(debug, "deliver message from broker Topic=~p, Payload=~p", [Topic, Payload]),
     deliver_to_coap(Topic, Payload, Subscribers),
-    ok;
-
-do_deliver(Pkt, _Subscribers) ->
-    ?LOG(warning, "unknown packet type to deliver, pkt=~p,", [Pkt]),
     ok.
 
 deliver_to_coap(_TopicName, _Payload, []) ->

apps/emqx_coap/src/emqx_coap_ps_topics.erl

@@ -104,7 +104,7 @@ lookup_topic_payload(Topic) ->
 %%--------------------------------------------------------------------
 
 init([]) ->
-    ets:new(?COAP_TOPIC_TABLE, [set, named_table, protected]),
+    _ = ets:new(?COAP_TOPIC_TABLE, [set, named_table, protected]),
     ?LOG(debug, "Create the coap_topic table", []),
     {ok, #state{}}.
 

apps/emqx_coap/src/emqx_coap_registry.erl

@@ -86,8 +86,8 @@ stop() ->
 %% ------------------------------------------------------------------
 
 init([]) ->
-    ets:new(?RESPONSE_TAB, [set, named_table, protected]),
-    ets:new(?RESPONSE_REF_TAB, [set, named_table, protected]),
+    _ = ets:new(?RESPONSE_TAB, [set, named_table, protected]),
+    _ = ets:new(?RESPONSE_REF_TAB, [set, named_table, protected]),
     {ok, #state{}}.
 
 handle_call({register_name, Name, Pid}, _From, State) ->

apps/emqx_dashboard/src/emqx_dashboard_admin.erl

@@ -137,7 +137,7 @@ change_password_hash(Username, PasswordHash) ->
 
 update_pwd(Username, Fun) ->
     Trans = fun() ->
-                    User = 
+                    User =
                     case lookup_user(Username) of
                     [Admin] -> Admin;
                     [] ->
@@ -180,7 +180,7 @@ check(Username, Password) ->
 
 init([]) ->
     %% Add default admin user
-    add_default_user(binenv(default_user_username), binenv(default_user_passwd)),
+    _ = add_default_user(binenv(default_user_username), binenv(default_user_passwd)),
     {ok, state}.
 
 handle_call(_Req, _From, State) ->
@@ -210,7 +210,7 @@ md5_hash(SaltBin, Password) ->
     erlang:md5(<<SaltBin/binary, Password/binary>>).
 
 salt() ->
-    emqx_misc:rand_seed(),
+    _ = emqx_misc:rand_seed(),
     Salt = rand:uniform(16#ffffffff),
     <<Salt:32>>.
 

apps/emqx_exhook/src/emqx_exhook.erl

@@ -64,9 +64,9 @@ disable(Name) ->
             unsave(Name)
     end.
 
--spec disable_all() -> [term()].
+-spec disable_all() -> ok.
 disable_all() ->
-    [begin disable(Name), Name end || Name <- running()].
+    lists:foreach(fun disable/1, running()).
 
 %%----------------------------------------------------------
 %% Dispatch APIs

apps/emqx_exhook/src/emqx_exhook_app.erl

@@ -45,7 +45,7 @@ start(_StartType, _StartArgs) ->
     load_all_servers(),
 
     %% Register all hooks
-    load_exhooks(),
+    _ = load_exhooks(),
 
     %% Register CLI
     emqx_ctl:register_command(exhook, {emqx_exhook_cli, cli}, []),
@@ -53,8 +53,8 @@ start(_StartType, _StartArgs) ->
 
 prep_stop(State) ->
     emqx_ctl:unregister_command(exhook),
-    unload_exhooks(),
-    unload_all_servers(),
+    _ = unload_exhooks(),
+    ok = unload_all_servers(),
     State.
 
 stop(_State) ->

apps/emqx_exproto/src/emqx_exproto_channel.erl

@@ -331,7 +331,7 @@ handle_call({publish, Topic, Qos, Payload},
         _ ->
             Msg = emqx_message:make(From, Qos, Topic, Payload),
             NMsg = emqx_mountpoint:mount(Mountpoint, Msg),
-            emqx:publish(NMsg),
+            _ = emqx:publish(NMsg),
             {reply, ok, Channel}
     end;
 

apps/emqx_exproto/src/emqx_exproto_conn.erl

@@ -52,7 +52,7 @@
 
 -record(state, {
           %% TCP/SSL/UDP/DTLS Wrapped Socket
-          socket :: esockd:socket(),
+          socket :: {esockd_transport, esockd:socket()} | {udp, _, _},
           %% Peername of the connection
           peername :: emqx_types:peername(),
           %% Sockname of the connection
@@ -451,8 +451,8 @@ handle_msg(Msg, State) ->
 
 terminate(Reason, State = #state{channel = Channel}) ->
     ?LOG(debug, "Terminated due to ~p", [Reason]),
-    emqx_exproto_channel:terminate(Reason, Channel),
-    close_socket(State),
+    _ = emqx_exproto_channel:terminate(Reason, Channel),
+    _ = close_socket(State),
     exit(Reason).
 
 %%--------------------------------------------------------------------
@@ -527,10 +527,10 @@ handle_timeout(TRef, Msg, State) ->
 process_incoming(Data, State = #state{idle_timer = IdleTimer}) ->
     ?LOG(debug, "RECV ~0p", [Data]),
     Oct = iolist_size(Data),
-    emqx_pd:inc_counter(incoming_bytes, Oct),
-    emqx_pd:inc_counter(incoming_pkt, 1),
-    emqx_pd:inc_counter(recv_pkt, 1),
-    emqx_pd:inc_counter(recv_msg, 1),
+    inc_counter(incoming_bytes, Oct),
+    inc_counter(incoming_pkt, 1),
+    inc_counter(recv_pkt, 1),
+    inc_counter(recv_msg, 1),
     % TODO:
     %ok = emqx_metrics:inc('bytes.received', Oct),
 
@@ -561,10 +561,10 @@ handle_outgoing(IoData, State = #state{socket = Socket}) ->
 
     Oct = iolist_size(IoData),
 
-    emqx_pd:inc_counter(send_pkt, 1),
-    emqx_pd:inc_counter(send_msg, 1),
-    emqx_pd:inc_counter(outgoing_pkt, 1),
-    emqx_pd:inc_counter(outgoing_bytes, Oct),
+    inc_counter(send_pkt, 1),
+    inc_counter(send_msg, 1),
+    inc_counter(outgoing_pkt, 1),
+    inc_counter(outgoing_bytes, Oct),
 
     %% FIXME:
     %%ok = emqx_metrics:inc('bytes.sent', Oct),
@@ -680,3 +680,7 @@ stop(Reason, State) ->
 
 stop(Reason, Reply, State) ->
     {stop, Reason, Reply, State}.
+
+inc_counter(Name, Value) ->
+    _ = emqx_pd:inc_counter(Name, Value),
+    ok.

apps/emqx_exproto/src/emqx_exproto_gcli.erl

@@ -74,22 +74,24 @@ handle_call(_Request, _From, State) ->
     {reply, ok, State}.
 
 handle_cast({rpc, Fun, Req, Options, From}, State) ->
-    case catch apply(?CONN_ADAPTER_MOD, Fun, [Req, Options]) of
-        {ok, Resp, _Metadata} ->
-            ?LOG(debug, "~p got {ok, ~0p, ~0p}", [Fun, Resp, _Metadata]),
-            reply(From, Fun, {ok, Resp});
-        {error, {Code, Msg}, _Metadata} ->
-            ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) response errcode: ~0p, errmsg: ~0p",
+    try
+        case apply(?CONN_ADAPTER_MOD, Fun, [Req, Options]) of
+            {ok, Resp, _Metadata} ->
+                ?LOG(debug, "~p got {ok, ~0p, ~0p}", [Fun, Resp, _Metadata]),
+                reply(From, Fun, {ok, Resp});
+            {error, {Code, Msg}, _Metadata} ->
+                ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) response errcode: ~0p, errmsg: ~0p",
                         [?CONN_ADAPTER_MOD, Fun, Req, Options, Code, Msg]),
-            reply(From, Fun, {error, {Code, Msg}});
-        {error, Reason} ->
-            ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) error: ~0p",
+                reply(From, Fun, {error, {Code, Msg}});
+            {error, Reason} ->
+                ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) error: ~0p",
                         [?CONN_ADAPTER_MOD, Fun, Req, Options, Reason]),
-            reply(From, Fun, {error, Reason});
-        {'EXIT', {Reason, Stk}} ->
-            ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) throw an exception: ~0p, stacktrace: ~0p",
-                        [?CONN_ADAPTER_MOD, Fun, Req, Options, Reason, Stk]),
-            reply(From, Fun, {error, Reason})
+                reply(From, Fun, {error, Reason})
+        end
+    catch _ : Rsn : Stk ->
+        ?LOG(error, "CALL ~0p:~0p(~0p, ~0p) throw an exception: ~0p, stacktrace: ~0p",
+             [?CONN_ADAPTER_MOD, Fun, Req, Options, Rsn, Stk]),
+        reply(From, Fun, {error, Rsn})
     end,
     {noreply, State}.
 
@@ -107,4 +109,5 @@ code_change(_OldVsn, State, _Extra) ->
 %%--------------------------------------------------------------------
 
 reply(Pid, Fun, Result) ->
-    Pid ! {hreply, Fun, Result}.
+    Pid ! {hreply, Fun, Result},
+    ok.

apps/emqx_lua_hook/src/emqx_lua_hook.erl

@@ -147,7 +147,7 @@ do_load(FileName) ->
                     error;
                 {Ret1, St1} ->
                     ?LOG(debug, "Register lua script ~p", [FileName]),
-                    do_register_hooks(Ret1, FileName, St1),
+                    _ = do_register_hooks(Ret1, FileName, St1),
                     {FileName, St1};
                 Other ->
                     ?LOG(error, "Failed to load lua script ~p, register_hook() raise exception ~p", [FileName, Other]),
@@ -184,7 +184,7 @@ do_register(Hook, ScriptName, _St) ->
 do_register_hooks([], _ScriptName, _St) ->
     ok;
 do_register_hooks([H|T], ScriptName, St) ->
-    do_register(H, ScriptName, St),
+    _ = do_register(H, ScriptName, St),
     do_register_hooks(T, ScriptName, St);
 do_register_hooks(Hook = <<$o, $n, _Rest/binary>>, ScriptName, St) ->
     do_register(Hook, ScriptName, St);

apps/emqx_lwm2m/rebar.config

@@ -1,5 +1,5 @@
 {deps,
- [{lwm2m_coap, {git, "https://github.com/emqx/lwm2m-coap", {tag, "v1.1.1"}}}
+ [{lwm2m_coap, {git, "https://github.com/emqx/lwm2m-coap", {tag, "v1.1.2"}}}
  ]}.
 
 {profiles,

apps/emqx_lwm2m/src/emqx_lwm2m_app.erl

@@ -30,7 +30,7 @@
 
 start(_Type, _Args) ->
     Pid = emqx_lwm2m_sup:start_link(),
-    lwm2m_coap_server:start_registry(),
+    _ = lwm2m_coap_server:start_registry(),
     lwm2m_coap_server_registry:add_handler([<<"rd">>], emqx_lwm2m_coap_resource, undefined),
     emqx_lwm2m_coap_server:start(application:get_all_env(?APP)),
     Pid.

apps/emqx_lwm2m/src/emqx_lwm2m_json.erl

@@ -240,10 +240,10 @@ insert_resource_into_object_instance([ResourceId, ResourceInstanceId], Value, Ac
     ?LOG(debug, "insert_resource_into_object_instance1() ResourceId=~p, ResourceInstanceId=~p, Value=~p, Acc=~p", [ResourceId, ResourceInstanceId, Value, Acc]),
     case find_resource(ResourceId, Acc) of
         undefined ->
-            NewList = insert_resource_instance_into_resource(ResourceInstanceId, Value, []),
+            NewList = insert_resource_instance_into_resource([ResourceInstanceId], Value, []),
             Acc++[#{tlv_multiple_resource=>integer(ResourceId), value=>NewList}];
         Resource = #{value:=List}->
-            NewList = insert_resource_instance_into_resource(ResourceInstanceId, Value, List),
+            NewList = insert_resource_instance_into_resource([ResourceInstanceId], Value, List),
             Acc2 = lists:delete(Resource, Acc),
             Acc2 ++ [Resource#{value=>NewList}]
     end;
@@ -251,18 +251,18 @@ insert_resource_into_object_instance([ResourceId], Value, Acc) ->
     ?LOG(debug, "insert_resource_into_object_instance2() ResourceId=~p, Value=~p, Acc=~p", [ResourceId, Value, Acc]),
     NewMap = #{tlv_resource_with_value=>integer(ResourceId), value=>Value},
     case find_resource(ResourceId, Acc) of
-        undeinfed ->
+        undefined ->
             Acc ++ [NewMap];
         Resource ->
             Acc2 = lists:delete(Resource, Acc),
             Acc2 ++ [NewMap]
     end.
 
-insert_resource_instance_into_resource(ResourceInstanceId, Value, Acc) ->
+insert_resource_instance_into_resource([ResourceInstanceId], Value, Acc) ->
     ?LOG(debug, "insert_resource_instance_into_resource() ResourceInstanceId=~p, Value=~p, Acc=~p", [ResourceInstanceId, Value, Acc]),
     NewMap = #{tlv_resource_instance=>integer(ResourceInstanceId), value=>Value},
     case find_resource_instance(ResourceInstanceId, Acc) of
-        undeinfed ->
+        undefined ->
             Acc ++ [NewMap];
         Resource ->
             Acc2 = lists:delete(Resource, Acc),

apps/emqx_lwm2m/src/emqx_lwm2m_message.erl

@@ -229,7 +229,7 @@ insert_resource_into_object_instance([ResourceId, ResourceInstanceId], Value, Ac
 insert_resource_into_object_instance([ResourceId], Value, Acc) ->
     NewMap = #{tlv_resource_with_value=>integer(ResourceId), value=>Value},
     case find_resource(ResourceId, Acc) of
-        undeinfed ->
+        undefined ->
             Acc ++ [NewMap];
         Resource ->
             Acc2 = lists:delete(Resource, Acc),
@@ -239,7 +239,7 @@ insert_resource_into_object_instance([ResourceId], Value, Acc) ->
 insert_resource_instance_into_resource(ResourceInstanceId, Value, Acc) ->
     NewMap = #{tlv_resource_instance=>integer(ResourceInstanceId), value=>Value},
     case find_resource_instance(ResourceInstanceId, Acc) of
-        undeinfed ->
+        undefined ->
             Acc ++ [NewMap];
         Resource ->
             Acc2 = lists:delete(Resource, Acc),

apps/emqx_lwm2m/src/emqx_lwm2m_protocol.erl

@@ -109,7 +109,7 @@ post_init(Lwm2mState = #lwm2m_state{endpoint_name = _EndpointName,
     Topic = downlink_topic(<<"register">>, Lwm2mState),
     subscribe(Topic, Lwm2mState),
     %% - report the registration info
-    send_to_broker(<<"register">>, #{<<"data">> => RegInfo}, Lwm2mState),
+    _ = send_to_broker(<<"register">>, #{<<"data">> => RegInfo}, Lwm2mState),
     Lwm2mState#lwm2m_state{mqtt_topic = Topic}.
 
 update_reg_info(NewRegInfo, Lwm2mState=#lwm2m_state{life_timer = LifeTimer, register_info = RegInfo,
@@ -124,7 +124,7 @@ update_reg_info(NewRegInfo, Lwm2mState=#lwm2m_state{life_timer = LifeTimer, regi
     end,
 
     %% - flush cached donwlink commands
-    flush_cached_downlink_messages(CoapPid),
+    _ = flush_cached_downlink_messages(CoapPid),
 
     %% - update the life timer
     UpdatedLifeTimer = emqx_lwm2m_timer:refresh_timer(
@@ -136,16 +136,16 @@ update_reg_info(NewRegInfo, Lwm2mState=#lwm2m_state{life_timer = LifeTimer, regi
 
 replace_reg_info(NewRegInfo, Lwm2mState=#lwm2m_state{life_timer = LifeTimer,
                                                      coap_pid = CoapPid}) ->
-    send_to_broker(<<"register">>, #{<<"data">> => NewRegInfo}, Lwm2mState),
+    _ = send_to_broker(<<"register">>, #{<<"data">> => NewRegInfo}, Lwm2mState),
 
     %% - flush cached donwlink commands
-    flush_cached_downlink_messages(CoapPid),
+    _ = flush_cached_downlink_messages(CoapPid),
 
     %% - update the life timer
     UpdatedLifeTimer = emqx_lwm2m_timer:refresh_timer(
                             maps:get(<<"lt">>, NewRegInfo), LifeTimer),
 
-    send_auto_observe(CoapPid, NewRegInfo),
+    _ = send_auto_observe(CoapPid, NewRegInfo),
 
     ?LOG(debug, "Replace RegInfo to: ~p", [NewRegInfo]),
     Lwm2mState#lwm2m_state{life_timer = UpdatedLifeTimer,
@@ -153,13 +153,13 @@ replace_reg_info(NewRegInfo, Lwm2mState=#lwm2m_state{life_timer = LifeTimer,
 
 send_ul_data(_EventType, <<>>, _Lwm2mState) -> ok;
 send_ul_data(EventType, Payload, Lwm2mState=#lwm2m_state{coap_pid = CoapPid}) ->
-    send_to_broker(EventType, Payload, Lwm2mState),
-    flush_cached_downlink_messages(CoapPid),
+    _ = send_to_broker(EventType, Payload, Lwm2mState),
+    _ = flush_cached_downlink_messages(CoapPid),
     Lwm2mState.
 
 auto_observe(Lwm2mState = #lwm2m_state{register_info = RegInfo,
                                        coap_pid = CoapPid}) ->
-    send_auto_observe(CoapPid, RegInfo),
+    _ = send_auto_observe(CoapPid, RegInfo),
     Lwm2mState.
 
 deliver(#message{topic = Topic, payload = Payload}, Lwm2mState = #lwm2m_state{coap_pid = CoapPid, register_info = RegInfo, started_at = StartedAt}) ->
@@ -297,7 +297,7 @@ observe_object(AlternatePath, ObjectPath, CoapPid) ->
 do_deliver_to_coap_slowly(CoapPid, CoapRequestList, Interval) ->
     erlang:spawn(fun() ->
         lists:foreach(fun({CoapRequest, Ref}) ->
-                do_deliver_to_coap(CoapPid, CoapRequest, Ref),
+                _ = do_deliver_to_coap(CoapPid, CoapRequest, Ref),
                 timer:sleep(Interval)
             end, lists:reverse(CoapRequestList))
         end).

apps/emqx_lwm2m/src/emqx_lwm2m_timer.erl

@@ -33,7 +33,7 @@
     logger:Level("LWM2M-TIMER: " ++ Format, Args)).
 
 cancel_timer(#timer_state{tref = TRef}) when is_reference(TRef) ->
-    erlang:cancel_timer(TRef), ok.
+    _ = erlang:cancel_timer(TRef), ok.
 
 refresh_timer(State=#timer_state{interval = Interval, message = Msg}) ->
     cancel_timer(State), start_timer(Interval, Msg).

apps/emqx_lwm2m/src/emqx_lwm2m_tlv.erl

@@ -20,6 +20,11 @@
         , encode/1
         ]).
 
+
+-ifdef(TEST).
+-export([binary_to_hex_string/1]).
+-endif.
+
 -include("emqx_lwm2m.hrl").
 
 -define(LOG(Level, Format, Args), logger:Level("LWM2M-TLV: " ++ Format, Args)).

apps/emqx_lwm2m/src/emqx_lwm2m_xml_object_db.erl

@@ -86,8 +86,8 @@ stop() ->
 %% ------------------------------------------------------------------
 
 init([]) ->
-    ets:new(?LWM2M_OBJECT_DEF_TAB, [set, named_table, protected]),
-    ets:new(?LWM2M_OBJECT_NAME_TO_ID_TAB, [set, named_table, protected]),
+    _ = ets:new(?LWM2M_OBJECT_DEF_TAB, [set, named_table, protected]),
+    _ = ets:new(?LWM2M_OBJECT_NAME_TO_ID_TAB, [set, named_table, protected]),
     PluginsEtcDir = emqx:get_env(plugins_etc_dir),
     DefBaseDir = re:replace(PluginsEtcDir, "plugins", "lwm2m_xml", [{return, list}]),
     BaseDir = application:get_env(emqx_lwm2m, xml_dir, DefBaseDir),

apps/emqx_management/src/emqx_mgmt.erl

@@ -585,7 +585,7 @@ delete_all_deactivated_alarms() ->
 
 delete_all_deactivated_alarms(Node) when Node =:= node() ->
     emqx_alarm:delete_all_deactivated_alarms();
-delete_all_deactivated_alarms(Node) -> 
+delete_all_deactivated_alarms(Node) ->
     rpc_call(Node, delete_deactivated_alarms, [Node]).
 
 %%--------------------------------------------------------------------
@@ -664,7 +664,7 @@ export_auth_username() ->
 export_auth_mnesia() ->
     case ets:info(emqx_user) of
         undefined -> [];
-        _ -> 
+        _ ->
             lists:foldl(fun({_, Login, Password, IsSuperuser}, Acc) ->
                             [[{login, Login}, {password, Password}, {is_superuser, IsSuperuser}] | Acc]
                         end, [], ets:tab2list(emqx_user))
@@ -764,7 +764,7 @@ import_auth_clientid(Lists) ->
     case ets:info(emqx_auth_clientid) of
         undefined -> ok;
         _ ->
-            [ mnesia:dirty_write({emqx_auth_clientid, ClientId, Password}) || #{<<"clientid">> := ClientId, 
+            [ mnesia:dirty_write({emqx_auth_clientid, ClientId, Password}) || #{<<"clientid">> := ClientId,
                                                                                <<"password">> := Password} <- Lists ]
     end.
 
@@ -772,14 +772,14 @@ import_auth_username(Lists) ->
     case ets:info(emqx_auth_username) of
         undefined -> ok;
         _ ->
-            [ mnesia:dirty_write({emqx_auth_username, Username, Password}) || #{<<"username">> := Username, 
+            [ mnesia:dirty_write({emqx_auth_username, Username, Password}) || #{<<"username">> := Username,
                                                                                <<"password">> := Password} <- Lists ]
     end.
 
 import_auth_mnesia(Auths) ->
     case ets:info(emqx_user) of
         undefined -> ok;
-        _ -> 
+        _ ->
             [ mnesia:dirty_write({emqx_user, Login, Password, IsSuperuser}) || #{<<"login">> := Login,
                                                                                  <<"password">> := Password,
                                                                                  <<"is_superuser">> := IsSuperuser} <- Auths ]
@@ -788,14 +788,14 @@ import_auth_mnesia(Auths) ->
 import_acl_mnesia(Acls) ->
     case ets:info(emqx_acl) of
         undefined -> ok;
-        _ -> 
-            [ mnesia:dirty_write({emqx_acl ,Login, Topic, Action, Allow}) || #{<<"login">> := Login, 
+        _ ->
+            [ mnesia:dirty_write({emqx_acl ,Login, Topic, Action, Allow}) || #{<<"login">> := Login,
                                                                                <<"topic">> := Topic,
                                                                                <<"action">> := Action,
                                                                                <<"allow">> := Allow} <- Acls ]
     end.
 
-import_schemas(Schemas) -> 
+import_schemas(Schemas) ->
     case ets:info(emqx_schema) of
         undefined -> ok;
         _ -> [emqx_schema_registry:add_schema(emqx_schema_api:make_schema_params(Schema)) || Schema <- Schemas]
@@ -817,7 +817,7 @@ to_version(Version) when is_list(Version) ->
 %%--------------------------------------------------------------------
 
 enable_telemetry() ->
-    [enable_telemetry(Node) || Node <- ekka_mnesia:running_nodes()], ok.
+    lists:foreach(fun enable_telemetry/1,ekka_mnesia:running_nodes()).
 
 enable_telemetry(Node) when Node =:= node() ->
     emqx_telemetry:enable();
@@ -825,7 +825,7 @@ enable_telemetry(Node) ->
     rpc_call(Node, enable_telemetry, [Node]).
 
 disable_telemetry() ->
-    [disable_telemetry(Node) || Node <- ekka_mnesia:running_nodes()], ok.
+    lists:foreach(fun disable_telemetry/1,ekka_mnesia:running_nodes()).
 
 disable_telemetry(Node) when Node =:= node() ->
     emqx_telemetry:disable();

apps/emqx_management/src/emqx_mgmt_api.erl

@@ -37,7 +37,9 @@ paginate(Tables, Params, RowFun) ->
     Limit = limit(Params),
     Cursor = qlc:cursor(Qh),
     case Page > 1 of
-        true  -> qlc:next_answers(Cursor, (Page - 1) * Limit);
+        true  ->
+            _ = qlc:next_answers(Cursor, (Page - 1) * Limit),
+            ok;
         false -> ok
     end,
     Rows = qlc:next_answers(Cursor, Limit),

apps/emqx_management/src/emqx_mgmt_api_alarms.erl

@@ -111,7 +111,7 @@ deactivate(_Bindings, Params) ->
     do_deactivate(Node, Name).
 
 delete_deactivated(Bindings, _Params) when map_size(Bindings) == 0 ->
-    emqx_mgmt:delete_all_deactivated_alarms(),
+    _ = emqx_mgmt:delete_all_deactivated_alarms(),
     {ok, #{code => ?SUCCESS}};
 
 delete_deactivated(#{node := Node}, _Params) ->
@@ -134,4 +134,4 @@ do_deactivate(Node, Name) ->
             minirest:return();
         {error, Reason} ->
             minirest:return({error, Reason})
-    end.
+    end.

apps/emqx_management/src/emqx_mgmt_api_data.erl

@@ -187,11 +187,11 @@ do_import(Filename) ->
                         emqx_mgmt:import_applications(maps:get(<<"apps">>, Data, [])),
                         emqx_mgmt:import_users(maps:get(<<"users">>, Data, [])),
                         emqx_mgmt:import_modules(maps:get(<<"modules">>, Data, [])),
-                        emqx_mgmt:import_auth_clientid(maps:get(<<"auth_clientid">>, Data, [])),
-                        emqx_mgmt:import_auth_username(maps:get(<<"auth_username">>, Data, [])),
-                        emqx_mgmt:import_auth_mnesia(maps:get(<<"auth_mnesia">>, Data, []), Version),
-                        emqx_mgmt:import_acl_mnesia(maps:get(<<"acl_mnesia">>, Data, []), Version),
-                        emqx_mgmt:import_schemas(maps:get(<<"schemas">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_clientid(maps:get(<<"auth_clientid">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_username(maps:get(<<"auth_username">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_mnesia(maps:get(<<"auth_mnesia">>, Data, []), Version),
+                        _ = emqx_mgmt:import_acl_mnesia(maps:get(<<"acl_mnesia">>, Data, []), Version),
+                        _ = emqx_mgmt:import_schemas(maps:get(<<"schemas">>, Data, [])),
                         logger:debug("The emqx data has been imported successfully"),
                         ok
                     catch Class:Reason:Stack ->

apps/emqx_management/src/emqx_mgmt_app.erl

@@ -26,7 +26,7 @@
 
 start(_Type, _Args) ->
     {ok, Sup} = emqx_mgmt_sup:start_link(),
-    emqx_mgmt_auth:add_default_app(),
+    _ = emqx_mgmt_auth:add_default_app(),
     emqx_mgmt_http:start_listeners(),
     emqx_mgmt_cli:load(),
     {ok, Sup}.

apps/emqx_management/src/emqx_mgmt_cli.erl

@@ -416,7 +416,7 @@ log(["primary-level"]) ->
     emqx_ctl:print("~s~n", [Level]);
 
 log(["primary-level", Level]) ->
-    emqx_logger:set_primary_log_level(list_to_atom(Level)),
+    _ = emqx_logger:set_primary_log_level(list_to_atom(Level)),
     emqx_ctl:print("~s~n", [emqx_logger:get_primary_log_level()]);
 
 log(["handlers", "list"]) ->
@@ -606,11 +606,11 @@ data(["import", Filename]) ->
                         emqx_mgmt:import_blacklist(maps:get(<<"blacklist">>, Data, [])),
                         emqx_mgmt:import_applications(maps:get(<<"apps">>, Data, [])),
                         emqx_mgmt:import_users(maps:get(<<"users">>, Data, [])),
-                        emqx_mgmt:import_auth_clientid(maps:get(<<"auth_clientid">>, Data, [])),
-                        emqx_mgmt:import_auth_username(maps:get(<<"auth_username">>, Data, [])),
-                        emqx_mgmt:import_auth_mnesia(maps:get(<<"auth_mnesia">>, Data, [])),
-                        emqx_mgmt:import_acl_mnesia(maps:get(<<"acl_mnesia">>, Data, [])),
-                        emqx_mgmt:import_schemas(maps:get(<<"schemas">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_clientid(maps:get(<<"auth_clientid">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_username(maps:get(<<"auth_username">>, Data, [])),
+                        _ = emqx_mgmt:import_auth_mnesia(maps:get(<<"auth_mnesia">>, Data, [])),
+                        _ = emqx_mgmt:import_acl_mnesia(maps:get(<<"acl_mnesia">>, Data, [])),
+                        _ = emqx_mgmt:import_schemas(maps:get(<<"schemas">>, Data, [])),
                         emqx_ctl:print("The emqx data has been imported successfully.~n")
                     catch Class:Reason:Stack ->
                         emqx_ctl:print("The emqx data import failed due: ~0p~n", [{Class,Reason,Stack}])

apps/emqx_plugin_template/src/emqx_plugin_template.erl

@@ -52,25 +52,25 @@
 
 %% Called when the plugin application start
 load(Env) ->
-    emqx:hook('client.connect',      {?MODULE, on_client_connect, [Env]}),
-    emqx:hook('client.connack',      {?MODULE, on_client_connack, [Env]}),
-    emqx:hook('client.connected',    {?MODULE, on_client_connected, [Env]}),
-    emqx:hook('client.disconnected', {?MODULE, on_client_disconnected, [Env]}),
-    emqx:hook('client.authenticate', {?MODULE, on_client_authenticate, [Env]}),
-    emqx:hook('client.check_acl',    {?MODULE, on_client_check_acl, [Env]}),
-    emqx:hook('client.subscribe',    {?MODULE, on_client_subscribe, [Env]}),
-    emqx:hook('client.unsubscribe',  {?MODULE, on_client_unsubscribe, [Env]}),
-    emqx:hook('session.created',     {?MODULE, on_session_created, [Env]}),
-    emqx:hook('session.subscribed',  {?MODULE, on_session_subscribed, [Env]}),
-    emqx:hook('session.unsubscribed',{?MODULE, on_session_unsubscribed, [Env]}),
-    emqx:hook('session.resumed',     {?MODULE, on_session_resumed, [Env]}),
-    emqx:hook('session.discarded',   {?MODULE, on_session_discarded, [Env]}),
-    emqx:hook('session.takeovered',  {?MODULE, on_session_takeovered, [Env]}),
-    emqx:hook('session.terminated',  {?MODULE, on_session_terminated, [Env]}),
-    emqx:hook('message.publish',     {?MODULE, on_message_publish, [Env]}),
-    emqx:hook('message.delivered',   {?MODULE, on_message_delivered, [Env]}),
-    emqx:hook('message.acked',       {?MODULE, on_message_acked, [Env]}),
-    emqx:hook('message.dropped',     {?MODULE, on_message_dropped, [Env]}).
+    hook('client.connect',      {?MODULE, on_client_connect, [Env]}),
+    hook('client.connack',      {?MODULE, on_client_connack, [Env]}),
+    hook('client.connected',    {?MODULE, on_client_connected, [Env]}),
+    hook('client.disconnected', {?MODULE, on_client_disconnected, [Env]}),
+    hook('client.authenticate', {?MODULE, on_client_authenticate, [Env]}),
+    hook('client.check_acl',    {?MODULE, on_client_check_acl, [Env]}),
+    hook('client.subscribe',    {?MODULE, on_client_subscribe, [Env]}),
+    hook('client.unsubscribe',  {?MODULE, on_client_unsubscribe, [Env]}),
+    hook('session.created',     {?MODULE, on_session_created, [Env]}),
+    hook('session.subscribed',  {?MODULE, on_session_subscribed, [Env]}),
+    hook('session.unsubscribed',{?MODULE, on_session_unsubscribed, [Env]}),
+    hook('session.resumed',     {?MODULE, on_session_resumed, [Env]}),
+    hook('session.discarded',   {?MODULE, on_session_discarded, [Env]}),
+    hook('session.takeovered',  {?MODULE, on_session_takeovered, [Env]}),
+    hook('session.terminated',  {?MODULE, on_session_terminated, [Env]}),
+    hook('message.publish',     {?MODULE, on_message_publish, [Env]}),
+    hook('message.delivered',   {?MODULE, on_message_delivered, [Env]}),
+    hook('message.acked',       {?MODULE, on_message_acked, [Env]}),
+    hook('message.dropped',     {?MODULE, on_message_dropped, [Env]}).
 
 %%--------------------------------------------------------------------
 %% Client Lifecircle Hooks
@@ -186,3 +186,8 @@ unload() ->
     emqx:unhook('message.acked',       {?MODULE, on_message_acked}),
     emqx:unhook('message.dropped',     {?MODULE, on_message_dropped}).
 
+hook(Name, MFA) ->
+    case emqx:hook(Name, MFA) of
+        ok -> ok;
+        {error, already_exists} -> ok
+    end.

apps/emqx_psk_file/src/emqx_psk_file.erl

@@ -34,10 +34,10 @@
 
 %% Called when the plugin application start
 load(Env) ->
-    ets:new(?TAB, [set, named_table, {keypos, #psk_entry.psk_id}]),
+    _ = ets:new(?TAB, [set, named_table, {keypos, #psk_entry.psk_id}]),
     {ok, PskFile} = file:open(get_value(path, Env), [read, raw, binary, read_ahead]),
     preload_psks(PskFile, bin(get_value(delimiter, Env))),
-    file:close(PskFile),
+    _ = file:close(PskFile),
     emqx:hook('tls_handshake.psk_lookup', fun ?MODULE:on_psk_lookup/2, []).
 
 %% Called when the plugin application stop

apps/emqx_psk_file/src/emqx_psk_file_app.erl

@@ -25,7 +25,7 @@
 
 start(_StartType, _StartArgs) ->
     {ok, Sup} = emqx_psk_file_sup:start_link(),
-    emqx_psk_file:load(
+    _ = emqx_psk_file:load(
         application:get_all_env(emqx_psk_file)),
     {ok, Sup}.
 

apps/emqx_retainer/src/emqx_retainer.erl

@@ -56,8 +56,9 @@
 %%--------------------------------------------------------------------
 
 load(Env) ->
-    emqx:hook('session.subscribed', fun ?MODULE:on_session_subscribed/3, []),
-    emqx:hook('message.publish', fun ?MODULE:on_message_publish/2, [Env]).
+    _ = emqx:hook('session.subscribed', fun ?MODULE:on_session_subscribed/3, []),
+    _ = emqx:hook('message.publish', fun ?MODULE:on_message_publish/2, [Env]),
+    ok.
 
 unload() ->
     emqx:unhook('message.publish', fun ?MODULE:on_message_publish/2),
@@ -169,15 +170,17 @@ handle_info(stats, State = #state{stats_fun = StatsFun}) ->
     {noreply, State, hibernate};
 
 handle_info(expire, State) ->
-    expire_messages(),
+    ok = expire_messages(),
     {noreply, State, hibernate};
 
 handle_info(Info, State) ->
     ?LOG(error, "Unexpected info: ~p", [Info]),
     {noreply, State}.
 
-terminate(_Reason, _State = #state{stats_timer = TRef1, expiry_timer = TRef2}) ->
-    timer:cancel(TRef1), timer:cancel(TRef2).
+terminate(_Reason, #state{stats_timer = TRef1, expiry_timer = TRef2} = State) ->
+    _ = timer:cancel(TRef1),
+    _ = timer:cancel(TRef2),
+    ok.
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
@@ -248,11 +251,12 @@ expire_messages() ->
     NowMs = erlang:system_time(millisecond),
     MsHd = #retained{topic = '$1', msg = '_', expiry_time = '$3'},
     Ms = [{MsHd, [{'=/=','$3',0}, {'<','$3',NowMs}], ['$1']}],
-    mnesia:transaction(
+    {atomic, _} = mnesia:transaction(
         fun() ->
             Keys = mnesia:select(?TAB, Ms, write),
             lists:foreach(fun(Key) -> mnesia:delete({?TAB, Key}) end, Keys)
-        end).
+        end),
+    ok.
 
 -spec(read_messages(emqx_types:topic())
       -> [emqx_types:message()]).

apps/emqx_rule_engine/include/rule_engine.hrl

@@ -60,7 +60,7 @@
         { id :: action_instance_id()
         , name :: action_name()
         , fallbacks :: list(#action_instance{})
-        , args :: #{atom() => term()} %% the args got from API for initializing action_instance
+        , args :: #{binary() => term()} %% the args got from API for initializing action_instance
         }).
 
 -record(rule,
@@ -82,7 +82,7 @@
         { id :: resource_id()
         , type :: resource_type_name()
         , config :: #{} %% the configs got from API for initializing resource
-        , created_at :: erlang:timestamp()
+        , created_at :: integer() %% epoch in millisecond precision
         , description :: binary()
         }).
 

apps/emqx_rule_engine/src/emqx_rule_engine.erl

@@ -39,6 +39,7 @@
         , get_resource_status/1
         , get_resource_params/1
         , delete_resource/1
+        , ensure_resource_deleted/1
         ]).
 
 -export([ init_resource/4
@@ -154,6 +155,7 @@ module_attributes(Module) ->
 %% APIs for rules and resources
 %%------------------------------------------------------------------------------
 
+-dialyzer([{nowarn_function, [create_rule/1, rule_id/0]}]).
 -spec(create_rule(#{}) -> {ok, rule()} | no_return()).
 create_rule(Params = #{rawsql := Sql, actions := Actions}) ->
     case emqx_rule_sqlparser:parse_select(Sql) of
@@ -178,7 +180,7 @@ create_rule(Params = #{rawsql := Sql, actions := Actions}) ->
         Error -> error(Error)
     end.
 
--spec(update_rule(#{}) -> {ok, rule()} | no_return()).
+-spec(update_rule(#{id := binary(), _=>_}) -> {ok, rule()} | {error, {not_found, rule_id()}}).
 update_rule(Params = #{id := RuleId}) ->
     case emqx_rule_registry:get_rule(RuleId) of
         {ok, Rule0} ->
@@ -205,7 +207,7 @@ delete_rule(RuleId) ->
             ok
     end.
 
--spec(create_resource(#{}) -> {ok, resource()} | {error, Reason :: term()}).
+-spec(create_resource(#{type := _, config := _, _ => _}) -> {ok, resource()} | {error, Reason :: term()}).
 create_resource(#{type := Type, config := Config} = Params) ->
     case emqx_rule_registry:find_resource_type(Type) of
         {ok, #resource_type{on_create = {M, F}, params_spec = ParamSpec}} ->
@@ -214,7 +216,9 @@ create_resource(#{type := Type, config := Config} = Params) ->
             Resource = #resource{id = ResId,
                                  type = Type,
                                  config = Config,
-                                 description = iolist_to_binary(maps:get(description, Params, ""))},
+                                 description = iolist_to_binary(maps:get(description, Params, "")),
+                                 created_at = erlang:system_time(millisecond)
+                                },
             ok = emqx_rule_registry:add_resource(Resource),
             %% Note that we will return OK in case of resource creation failure,
             %% users can always re-start the resource later.
@@ -230,14 +234,14 @@ start_resource(ResId) ->
         {ok, #resource{type = ResType, config = Config}} ->
             {ok, #resource_type{on_create = {Mod, Create}}}
                 = emqx_rule_registry:find_resource_type(ResType),
-            init_resource(Mod, Create, ResId, Config),
+            _ = init_resource(Mod, Create, ResId, Config),
             refresh_actions_of_a_resource(ResId),
             ok;
         not_found ->
             {error, {resource_not_found, ResId}}
     end.
 
--spec(test_resource(#{}) -> ok | {error, Reason :: term()}).
+-spec(test_resource(#{type := _, config := _, _ => _}) -> ok | {error, Reason :: term()}).
 test_resource(#{type := Type, config := Config}) ->
     case emqx_rule_registry:find_resource_type(Type) of
         {ok, #resource_type{on_create = {ModC,Create}, on_destroy = {ModD,Destroy}, params_spec = ParamSpec}} ->
@@ -283,6 +287,12 @@ delete_resource(ResId) ->
             {error, {resource_not_found, ResId}}
     end.
 
+%% @doc Ensure resource deleted. `resource_not_found` error is discarded.
+-spec(ensure_resource_deleted(resource_id()) -> ok).
+ensure_resource_deleted(ResId) ->
+    _ = delete_resource(ResId),
+    ok.
+
 %%------------------------------------------------------------------------------
 %% Re-establish resources
 %%------------------------------------------------------------------------------
@@ -364,8 +374,7 @@ with_resource_params(Args = #{<<"$resource">> := ResId}) ->
     end;
 with_resource_params(Args) -> Args.
 
-may_update_rule_params(Rule, Params) when map_size(Params) =:= 0 ->
-    Rule;
+-dialyzer([{nowarn_function, may_update_rule_params/2}]).
 may_update_rule_params(Rule, Params = #{rawsql := SQL}) ->
     case emqx_rule_sqlparser:parse_select(SQL) of
         {ok, Select} ->
@@ -530,12 +539,12 @@ fetch_resource_status(Module, OnStatus, ResId) ->
     end.
 
 refresh_actions_of_a_resource(ResId) ->
-    [refresh_actions(Actions,
-        fun (#action_instance{args = #{<<"$resource">> := ResId0}})
+    R = fun (#action_instance{args = #{<<"$resource">> := ResId0}})
                 when ResId0 =:= ResId -> true;
             (_) -> false
-        end)
-     || #rule{actions = Actions} <- emqx_rule_registry:get_rules()].
+        end,
+    F = fun(#rule{actions = Actions}) -> refresh_actions(Actions, R) end,
+    lists:foreach(F, emqx_rule_registry:get_rules()).
 
 refresh_actions(Actions) ->
     refresh_actions(Actions, fun(_) -> true end).

apps/emqx_rule_engine/src/emqx_rule_engine_api.erl

@@ -22,6 +22,9 @@
 
 -import(minirest,  [return/1]).
 
+%% A lot of case clause no_match:es from rule_events.hrl
+-dialyzer(no_match).
+
 -rest_api(#{name   => create_rule,
             method => 'POST',
             path   => "/rules/",
@@ -352,7 +355,7 @@ start_resource(#{id := Id}, _Params) ->
 
 delete_resource(#{id := Id}, _Params) ->
     try
-        emqx_rule_engine:delete_resource(Id),
+        ok = emqx_rule_engine:ensure_resource_deleted(Id),
         return(ok)
     catch
         _Error:{throw,Reason} ->

apps/emqx_rule_engine/src/emqx_rule_engine_sup.erl

@@ -31,8 +31,8 @@ start_link() ->
 
 init([]) ->
     Opts = [public, named_table, set, {read_concurrency, true}],
-    ets:new(?ACTION_INST_PARAMS_TAB, [{keypos, #action_instance_params.id}|Opts]),
-    ets:new(?RES_PARAMS_TAB, [{keypos, #resource_params.id}|Opts]),
+    _ = ets:new(?ACTION_INST_PARAMS_TAB, [{keypos, #action_instance_params.id}|Opts]),
+    _ = ets:new(?RES_PARAMS_TAB, [{keypos, #resource_params.id}|Opts]),
     Registry = #{id => emqx_rule_registry,
                  start => {emqx_rule_registry, start_link, []},
                  restart => permanent,

apps/emqx_rule_engine/src/emqx_rule_events.erl

@@ -56,9 +56,10 @@
 -endif.
 
 load(Env) ->
-    [emqx_hooks:add(HookPoint, {?MODULE, hook_fun(HookPoint), [hook_conf(HookPoint, Env)]})
-     || HookPoint <- ?SUPPORTED_HOOK],
-    ok.
+    lists:foreach(
+      fun(HookPoint) ->
+              ok = emqx_hooks:put(HookPoint, {?MODULE, hook_fun(HookPoint), [hook_conf(HookPoint, Env)]})
+      end, ?SUPPORTED_HOOK).
 
 unload(_Env) ->
     [emqx_hooks:del(HookPoint, {?MODULE, hook_fun(HookPoint)})
@@ -291,7 +292,8 @@ may_publish_and_apply(EventName, GenEventMsg, #{enabled := true, qos := QoS}) ->
     EventMsg = GenEventMsg(),
     case emqx_json:safe_encode(EventMsg) of
         {ok, Payload} ->
-            emqx_broker:safe_publish(make_msg(QoS, EventTopic, Payload));
+            _ = emqx_broker:safe_publish(make_msg(QoS, EventTopic, Payload)),
+            ok;
         {error, _Reason} ->
             ?LOG(error, "Failed to encode event msg for ~p, msg: ~p", [EventName, EventMsg])
     end,

apps/emqx_rule_engine/src/emqx_rule_funcs.erl

@@ -515,25 +515,28 @@ sprintf_s(Format, Args) when is_list(Args) ->
     erlang:iolist_to_binary(io_lib:format(binary_to_list(Format), Args)).
 
 pad(S, Len) when is_binary(S), is_integer(Len) ->
-   iolist_to_binary(string:pad(S, Len, trailing)).
+    iolist_to_binary(string:pad(S, Len, trailing)).
 
 pad(S, Len, <<"trailing">>) when is_binary(S), is_integer(Len) ->
-   iolist_to_binary(string:pad(S, Len, trailing));
+    iolist_to_binary(string:pad(S, Len, trailing));
 
 pad(S, Len, <<"both">>) when is_binary(S), is_integer(Len) ->
-   iolist_to_binary(string:pad(S, Len, both));
+    iolist_to_binary(string:pad(S, Len, both));
 
 pad(S, Len, <<"leading">>) when is_binary(S), is_integer(Len) ->
-   iolist_to_binary(string:pad(S, Len, leading)).
+    iolist_to_binary(string:pad(S, Len, leading)).
 
 pad(S, Len, <<"trailing">>, Char) when is_binary(S), is_integer(Len), is_binary(Char) ->
-   iolist_to_binary(string:pad(S, Len, trailing, Char));
+    Chars = unicode:characters_to_list(Char, utf8),
+    iolist_to_binary(string:pad(S, Len, trailing, Chars));
 
 pad(S, Len, <<"both">>, Char) when is_binary(S), is_integer(Len), is_binary(Char) ->
-   iolist_to_binary(string:pad(S, Len, both, Char));
+    Chars = unicode:characters_to_list(Char, utf8),
+    iolist_to_binary(string:pad(S, Len, both, Chars));
 
 pad(S, Len, <<"leading">>, Char) when is_binary(S), is_integer(Len), is_binary(Char) ->
-   iolist_to_binary(string:pad(S, Len, leading, Char)).
+    Chars = unicode:characters_to_list(Char, utf8),
+    iolist_to_binary(string:pad(S, Len, leading, Chars)).
 
 replace(SrcStr, P, RepStr) when is_binary(SrcStr), is_binary(P), is_binary(RepStr) ->
     iolist_to_binary(string:replace(SrcStr, P, RepStr, all)).

apps/emqx_rule_engine/src/emqx_rule_metrics.erl

@@ -99,18 +99,18 @@
 
 -record(state, {
             metric_ids = sets:new(),
-            rule_speeds :: #{rule_id() => #rule_speed{}},
+            rule_speeds :: undefined | #{rule_id() => #rule_speed{}},
             overall_rule_speed :: #rule_speed{}
         }).
 
 %%------------------------------------------------------------------------------
 %% APIs
 %%------------------------------------------------------------------------------
--spec(create_rule_metrics(rule_id()) -> Ref :: reference()).
+-spec(create_rule_metrics(rule_id()) -> Ref :: counters:counters_ref()).
 create_rule_metrics(Id) ->
     gen_server:call(?MODULE, {create_rule_metrics, Id}).
 
--spec(create_metrics(rule_id()) -> Ref :: reference()).
+-spec(create_metrics(rule_id()) -> Ref :: counters:counters_ref()).
 create_metrics(Id) ->
     gen_server:call(?MODULE, {create_metrics, Id}).
 
@@ -133,7 +133,7 @@ get(Id, Metric) ->
 get_overall(Metric) ->
     emqx_metrics:val(Metric).
 
--spec(get_rule_speed(atom()) -> map()).
+-spec(get_rule_speed(rule_id()) -> map()).
 get_rule_speed(Id) ->
     gen_server:call(?MODULE, {get_rule_speed, Id}).
 
@@ -157,14 +157,16 @@ get_action_metrics(Id) ->
       taken => get_actions_taken(Id)
      }.
 
--spec(inc(rule_id(), atom()) -> ok).
+-spec inc(rule_id(), atom()) -> ok.
 inc(Id, Metric) ->
     inc(Id, Metric, 1).
+
+-spec inc(rule_id(), atom(), pos_integer()) -> ok.
 inc(Id, Metric, Val) ->
     counters:add(couters_ref(Id), metrics_idx(Metric), Val),
     inc_overall(Metric, Val).
 
--spec(inc_overall(rule_id(), atom()) -> ok).
+-spec(inc_overall(atom(), pos_integer()) -> ok).
 inc_overall(Metric, Val) ->
     emqx_metrics:inc(Metric, Val).
 

apps/emqx_rule_engine/src/emqx_rule_registry.erl

@@ -166,6 +166,10 @@ start_link() ->
 get_rules() ->
     get_all_records(?RULE_TAB).
 
+%% TODO: emqx_rule_utils:can_topic_match_oneof(Topic::any(), For::atom())
+%% will never return since it differs in the 2nd argument from the success
+%% typing arguments: (any(), [binary() | ['' | '#' | '+' | binary()]])
+-dialyzer([{nowarn_function, get_rules_for/1}]).
 -spec(get_rules_for(Topic :: binary()) -> list(emqx_rule_engine:rule())).
 get_rules_for(Topic) ->
     [Rule || Rule = #rule{for = For} <- get_rules(),
@@ -329,9 +333,10 @@ remove_resource_params(ResId) ->
 
 %% @private
 delete_resource(ResId) ->
-    [[ResId =:= ResId1 andalso throw({dependency_exists, {rule, Id}})
-        || #action_instance{args = #{<<"$resource">> := ResId1}} <- Actions]
-            || #rule{id = Id, actions = Actions} <- get_rules()],
+    %% TODO, change to foreache:s
+    _ = [[ResId =:= ResId1 andalso throw({dependency_exists, {rule, Id}})
+            || #action_instance{args = #{<<"$resource">> := ResId1}} <- Actions]
+                || #rule{id = Id, actions = Actions} <- get_rules()],
     mnesia:delete(?RES_TAB, ResId, write).
 
 %% @private

apps/emqx_rule_engine/src/emqx_rule_runtime.erl

@@ -49,7 +49,7 @@ apply_rules([], _Input) ->
 apply_rules([#rule{enabled = false}|More], Input) ->
     apply_rules(More, Input);
 apply_rules([Rule = #rule{id = RuleID}|More], Input) ->
-    try apply_rule(Rule, Input)
+    try apply_rule_discard_result(Rule, Input)
     catch
         %% ignore the errors if select or match failed
         _:{select_and_transform_error, Error} ->
@@ -70,6 +70,13 @@ apply_rules([Rule = #rule{id = RuleID}|More], Input) ->
     end,
     apply_rules(More, Input).
 
+apply_rule_discard_result(Rule, Input) ->
+    %% TODO check if below two clauses are ok to discard:
+    %% {'error','nomatch'}
+    %% {'ok',[any()]}
+    _ = apply_rule(Rule, Input),
+    ok.
+
 apply_rule(Rule = #rule{id = RuleID}, Input) ->
     clear_rule_payload(),
     do_apply_rule(Rule, add_metadata(Input, #{rule_id => RuleID})).
@@ -160,6 +167,7 @@ select_and_collect([Field|More], Input, {Output, LastKV}) ->
         {nested_put(Key, Val, Output), LastKV}).
 
 %% Filter each item got from FOREACH
+-dialyzer({nowarn_function, filter_collection/4}).
 filter_collection(Input, InCase, DoEach, {CollKey, CollVal}) ->
     lists:filtermap(
         fun(Item) ->
@@ -242,7 +250,7 @@ take_action(#action_instance{id = Id, name = ActName, fallbacks = Fallbacks} = A
         error:{badfun, _Func}:_ST ->
             %?LOG(warning, "Action ~p maybe outdated, refresh it and try again."
             %              "Func: ~p~nST:~0p", [Id, Func, ST]),
-            trans_action_on(Id, fun() ->
+            _ = trans_action_on(Id, fun() ->
                 emqx_rule_engine:refresh_actions([ActInst])
             end, 5000),
             emqx_rule_metrics:inc_actions_retry(Id),
@@ -291,11 +299,11 @@ wait_action_on(Id, RetryN) ->
 
 handle_action_failure(continue, Id, Fallbacks, Selected, Envs, Reason) ->
     ?LOG(error, "Take action ~p failed, continue next action, reason: ~0p", [Id, Reason]),
-    take_actions(Fallbacks, Selected, Envs, continue),
+    _ = take_actions(Fallbacks, Selected, Envs, continue),
     failed;
 handle_action_failure(stop, Id, Fallbacks, Selected, Envs, Reason) ->
     ?LOG(error, "Take action ~p failed, skip all actions, reason: ~0p", [Id, Reason]),
-    take_actions(Fallbacks, Selected, Envs, continue),
+    _ = take_actions(Fallbacks, Selected, Envs, continue),
     error({take_action_failed, {Id, Reason}}).
 
 eval({path, [{key, <<"payload">>} | Path]}, #{payload := Payload}) ->

apps/emqx_rule_engine/src/emqx_rule_sqlparser.erl

@@ -49,6 +49,10 @@
 
 -export_type([select/0]).
 
+%% Dialyzer gives up on the generated code.
+%% probably due to stack depth, or inlines.
+-dialyzer({nowarn_function, [parse_select/1]}).
+
 %% Parse one select statement.
 -spec(parse_select(string() | binary())
       -> {ok, select()} | {parse_error, term()} | {lex_error, term()}).
@@ -76,7 +80,7 @@ parse_select(Sql) ->
         end
     catch
         _Error:Reason:StackTrace ->
-            {parse_error, Reason, StackTrace}
+            {parse_error, {Reason, StackTrace}}
     end.
 
 -spec(select_fields(select()) -> list(field())).

apps/emqx_rule_engine/src/emqx_rule_sqltester.erl

@@ -21,24 +21,30 @@
 -export([ test/1
         ]).
 
+%% Dialyzer gives up on the generated code.
+%% probably due to stack depth, or inlines.
+-dialyzer({nowarn_function, [test/1,
+                             test_rule/4,
+                             flatten/1,
+                             sql_test_action/0,
+                             fill_default_values/2
+                             ]}).
+
 -spec(test(#{}) -> {ok, Result::map()} | no_return()).
 test(#{<<"rawsql">> := Sql, <<"ctx">> := Context}) ->
-    case emqx_rule_sqlparser:parse_select(Sql) of
-        {ok, Select} ->
-            InTopic = maps:get(<<"topic">>, Context, <<>>),
-            EventTopics = emqx_rule_sqlparser:select_from(Select),
-            case lists:all(fun is_publish_topic/1, EventTopics) of
-                true ->
-                    %% test if the topic matches the topic filters in the rule
-                    case emqx_rule_utils:can_topic_match_oneof(InTopic, EventTopics) of
-                        true -> test_rule(Sql, Select, Context, EventTopics);
-                        false -> {error, nomatch}
-                    end;
-                false ->
-                    %% the rule is for both publish and events, test it directly
-                    test_rule(Sql, Select, Context, EventTopics)
+    {ok, Select} = emqx_rule_sqlparser:parse_select(Sql),
+    InTopic = maps:get(<<"topic">>, Context, <<>>),
+    EventTopics = emqx_rule_sqlparser:select_from(Select),
+    case lists:all(fun is_publish_topic/1, EventTopics) of
+        true ->
+            %% test if the topic matches the topic filters in the rule
+            case emqx_rule_utils:can_topic_match_oneof(InTopic, EventTopics) of
+                true -> test_rule(Sql, Select, Context, EventTopics);
+                false -> {error, nomatch}
             end;
-        Error -> error(Error)
+        false ->
+            %% the rule is for both publish and events, test it directly
+            test_rule(Sql, Select, Context, EventTopics)
     end.
 
 test_rule(Sql, Select, Context, EventTopics) ->

apps/emqx_rule_engine/src/emqx_rule_validator.erl

@@ -31,25 +31,31 @@
 %% APIs
 %%------------------------------------------------------------------------------
 
-%% Validate the params according the spec and return a new spec.
-%% Note that this function will throw out exceptions in case of
-%% validation failure.
--spec(validate_params(params(), params_spec()) -> params()).
+%% Validate the params according the spec.
+%% Note that this function throws exception in case of validation failure.
+-spec(validate_params(params(), params_spec()) -> ok).
 validate_params(Params, ParamsSepc) ->
-    maps:map(fun(Name, Spec) ->
+    F = fun(Name, Spec) ->
             do_validate_param(Name, Spec, Params)
-        end, ParamsSepc),
-    ok.
+        end,
+    map_foreach(F, ParamsSepc).
 
 -spec(validate_spec(params_spec()) -> ok).
-validate_spec(ParamsSepc) ->
-    maps:map(fun do_validate_spec/2, ParamsSepc),
-    ok.
+validate_spec(ParamsSepc) -> map_foreach(fun do_validate_spec/2, ParamsSepc).
 
 %%------------------------------------------------------------------------------
 %% Internal Functions
 %%------------------------------------------------------------------------------
 
+map_foreach(Fun, Map) ->
+    Iterator = maps:iterator(Map),
+    map_foreach_loop(Fun, maps:next(Iterator)).
+
+map_foreach_loop(_Fun, none) -> ok;
+map_foreach_loop(Fun, {Key, Value, Iterator}) ->
+    _ = Fun(Key, Value),
+    map_foreach_loop(Fun, maps:next(Iterator)).
+
 do_validate_param(Name, Spec = #{required := true}, Params) ->
     find_field(Name, Params,
         fun (not_found) -> error({required_field_missing, Name});
@@ -171,5 +177,5 @@ do_find_field([F | Fields], Spec, Func) ->
     end.
 
 bin(Atom) when is_atom(Atom) -> atom_to_binary(Atom, utf8);
-bin(Str) when is_list(Str) -> atom_to_list(Str);
+bin(Str) when is_list(Str) -> iolist_to_binary(Str);
 bin(Bin) when is_binary(Bin) -> Bin.

apps/emqx_sasl/src/emqx_sasl_app.erl

@@ -30,7 +30,7 @@
 
 start(_Type, _Args) ->
     ok = emqx_sasl:init(),
-    emqx_sasl:load(),
+    _ = emqx_sasl:load(),
     emqx_sasl_cli:load(),
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
@@ -43,4 +43,4 @@ stop(_State) ->
 %%--------------------------------------------------------------------
 
 init([]) ->
-    {ok, { {one_for_all, 1, 10}, []} }.
+    {ok, { {one_for_all, 1, 10}, []} }.

apps/emqx_sasl/src/emqx_sasl_scram.erl

@@ -217,12 +217,8 @@ nonce() ->
     base64:encode([$a + rand:uniform(26) || _ <- lists:seq(1, 10)]).
 
 pbkdf2_sha_1(Password, Salt, IterationCount) ->
-    case pbkdf2:pbkdf2(sha, Password, Salt, IterationCount) of
-        {ok, Bin} ->
-            pbkdf2:to_hex(Bin);
-        {error, Reason} ->
-            error(Reason)
-    end.
+    {ok, Bin} = pbkdf2:pbkdf2(sha, Password, Salt, IterationCount),
+    pbkdf2:to_hex(Bin).
 
 -if(?OTP_RELEASE >= 23).
 hmac(Key, Data) ->

apps/emqx_sn/src/emqx_sn_gateway.erl

@@ -74,7 +74,7 @@
                 sockstate            :: emqx_types:sockstate(),
                 sockname             :: {inet:ip_address(), inet:port()},
                 peername             :: {inet:ip_address(), inet:port()},
-                channel              :: emqx_channel:channel(),
+                channel              :: maybe(emqx_channel:channel()),
                 registry             :: emqx_sn_registry:registry(),
                 clientid             :: maybe(binary()),
                 username             :: maybe(binary()),
@@ -105,6 +105,8 @@
 
 -define(NO_PEERCERT, undefined).
 
+%% TODO: fix when https://github.com/emqx/emqx-sn/pull/170 is merged
+-dialyzer([{nowarn_function, [idle/3]}]).
 
 %%--------------------------------------------------------------------
 %% Exported APIs
@@ -136,7 +138,8 @@ init([{_, SockPid, Sock}, Peername, Options]) ->
     EnableStats = proplists:get_value(enable_stats, Options, false),
     case inet:sockname(Sock) of
         {ok, Sockname} ->
-            Channel = emqx_channel:init(#{sockname => Sockname,
+            Channel = emqx_channel:init(#{socktype => udp,
+                                          sockname => Sockname,
                                           peername => Peername,
                                           protocol => 'mqtt-sn',
                                           peercert => ?NO_PEERCERT,
@@ -195,14 +198,18 @@ idle(cast, {incoming, ?SN_PUBLISH_MSG(_Flag, _TopicId, _MsgId, _Data)}, State =
 idle(cast, {incoming, ?SN_PUBLISH_MSG(#mqtt_sn_flags{qos = ?QOS_NEG1,
                                                      topic_id_type = TopicIdType
                                                     }, TopicId, _MsgId, Data)},
-     State = #state{clientid = ClientId, registry = Registry}) ->
+    State = #state{clientid = ClientId, registry = Registry}) ->
     TopicName = case (TopicIdType =:= ?SN_SHORT_TOPIC) of
-                    false ->
-                        emqx_sn_registry:lookup_topic(Registry, ClientId, TopicId);
+                    false -> emqx_sn_registry:lookup_topic(Registry, ClientId, TopicId);
                     true  -> <<TopicId:16>>
                 end,
-    Msg = emqx_message:make(?NEG_QOS_CLIENT_ID, ?QOS_0, TopicName, Data),
-    (TopicName =/= undefined) andalso emqx_broker:publish(Msg),
+    case TopicName =/= undefined of
+        true ->
+            Msg = emqx_message:make(?NEG_QOS_CLIENT_ID, ?QOS_0, TopicName, Data),
+            emqx_broker:publish(Msg);
+        false ->
+            ok
+    end,
     ?LOG(debug, "Client id=~p receives a publish with QoS=-1 in idle mode!", [ClientId], State),
     {keep_state_and_data, State#state.idle_timeout};
 
@@ -473,10 +480,10 @@ handle_event(info, {datagram, SockPid, Data}, StateName,
              State = #state{sockpid = SockPid, channel = _Channel}) ->
     ?LOG(debug, "RECV ~p", [Data], State),
     Oct = iolist_size(Data),
-    emqx_pd:inc_counter(recv_oct, Oct),
+    inc_counter(recv_oct, Oct),
     try emqx_sn_frame:parse(Data) of
         {ok, Msg} ->
-            emqx_pd:inc_counter(recv_cnt, 1),
+            inc_counter(recv_cnt, 1),
             ?LOG(info, "RECV ~s at state ~s",
                  [emqx_sn_frame:format(Msg), StateName], State),
             {keep_state, State, next_event({incoming, Msg})}
@@ -562,10 +569,9 @@ terminate(Reason, _StateName, #state{clientid = ClientId,
                                      channel  = Channel,
                                      registry = Registry}) ->
     emqx_sn_registry:unregister_topic(Registry, ClientId),
-    case {Channel, Reason} of
-        {undefined, _} -> ok;
-        {_, _} ->
-            emqx_channel:terminate(Reason, Channel)
+    case Channel =:= undefined of
+        true -> ok;
+        false -> emqx_channel:terminate(Reason, Channel)
     end.
 
 code_change(_Vsn, StateName, State, _Extra) ->
@@ -597,8 +603,8 @@ handle_info(Info, State = #state{channel = Channel}) ->
    handle_return(emqx_channel:handle_info(Info, Channel), State).
 
 handle_ping(_PingReq, State) ->
-    emqx_pd:inc_counter(recv_oct, 2),
-    emqx_pd:inc_counter(recv_msg, 1),
+    inc_counter(recv_oct, 2),
+    inc_counter(recv_msg, 1),
     ok = send_message(?SN_PINGRESP_MSG(), State),
     {keep_state, State}.
 
@@ -947,7 +953,7 @@ do_publish_will(#state{will_msg = WillMsg, clientid = ClientId}) ->
                                                           qos = QoS, retain = Retain},
                            variable = #mqtt_packet_publish{topic_name = Topic, packet_id = 1000},
                            payload  = Payload},
-    emqx_broker:publish(emqx_packet:to_message(Publish, ClientId)),
+    _ = emqx_broker:publish(emqx_packet:to_message(Publish, ClientId)),
     ok.
 
 do_puback(TopicId, MsgId, ReturnCode, _StateName,
@@ -1075,18 +1081,24 @@ transform_fun() ->
     fun(Packet, State) -> transform(Packet, FunMsgIdToTopicId, State) end.
 
 inc_incoming_stats(Type) ->
-    emqx_pd:inc_counter(recv_pkt, 1),
+    inc_counter(recv_pkt, 1),
     case Type == ?PUBLISH of
         true ->
-            emqx_pd:inc_counter(recv_msg, 1),
-            emqx_pd:inc_counter(incoming_pubs, 1);
+            inc_counter(recv_msg, 1),
+            inc_counter(incoming_pubs, 1);
         false -> ok
     end.
 
 inc_outgoing_stats(Type) ->
-    emqx_pd:inc_counter(send_pkt, 1),
-    (Type == ?SN_PUBLISH)
-        andalso emqx_pd:inc_counter(send_msg, 1).
+    inc_counter(send_pkt, 1),
+    case Type =:= ?SN_PUBLISH of
+        true -> inc_counter(send_msg, 1);
+        false -> ok
+    end.
 
 next_event(Content) ->
     {next_event, cast, Content}.
+
+inc_counter(Key, Inc) ->
+    _ = emqx_pd:inc_counter(Key, Inc),
+    ok.

apps/emqx_stomp/include/emqx_stomp.hrl

@@ -24,7 +24,7 @@
 %% STOMP Frame
 %%--------------------------------------------------------------------
 
--record(stomp_frame, {command, headers = [], body = <<>> :: iolist()}).
+-record(stomp_frame, {command, headers = [], body = <<>> :: iodata()}).
 
 -type(stomp_frame() :: #stomp_frame{}).
 

apps/emqx_stomp/src/emqx_stomp_frame.erl

@@ -87,7 +87,11 @@
 
 -define(IS_ESC(Ch), Ch == ?CR; Ch == ?LF; Ch == ?BSL; Ch == ?COLON).
 
--record(parser_state, {cmd, headers = [], hdname, acc = <<>>, limit}).
+-record(parser_state, {cmd,
+                       headers = [],
+                       hdname,
+                       acc = <<>> :: binary(),
+                       limit}).
 
 -record(frame_limit, {max_header_num, max_header_length, max_body_length}).
 

apps/emqx_stomp/src/emqx_stomp_protocol.erl

@@ -99,12 +99,12 @@ received(#stomp_frame{command = <<"CONNECT">>, headers = Headers},
                     send(connected_frame([{<<"version">>, Version},
                                           {<<"heart-beat">>, reverse_heartbeats(Heartbeats)}]), NewState);
                 false ->
-                    send(error_frame(undefined, <<"Login or passcode error!">>), State),
+                    _ = send(error_frame(undefined, <<"Login or passcode error!">>), State),
                     {error, login_or_passcode_error, State}
              end;
         {error, Msg} ->
-            send(error_frame([{<<"version">>, <<"1.0,1.1,1.2">>},
-                              {<<"content-type">>, <<"text/plain">>}], undefined, Msg), State),
+            _ = send(error_frame([{<<"version">>, <<"1.0,1.1,1.2">>},
+                                  {<<"content-type">>, <<"text/plain">>}], undefined, Msg), State),
             {error, unsupported_version, State}
     end;
 
@@ -114,10 +114,9 @@ received(#stomp_frame{command = <<"CONNECT">>}, State = #stomp_proto{connected =
 received(#stomp_frame{command = <<"SEND">>, headers = Headers, body = Body}, State) ->
     Topic = header(<<"destination">>, Headers),
     Action = fun(State0) ->
-                 maybe_send_receipt(receipt_id(Headers), State0),
-                 emqx_broker:publish(
-                     make_mqtt_message(Topic, Headers, iolist_to_binary(Body))
-                 ),
+                 _ = maybe_send_receipt(receipt_id(Headers), State0),
+                 _ = emqx_broker:publish(
+                       make_mqtt_message(Topic, Headers, iolist_to_binary(Body))),
                  State0
              end,
     case header(<<"transaction">>, Headers) of
@@ -160,7 +159,7 @@ received(#stomp_frame{command = <<"UNSUBSCRIBE">>, headers = Headers},
 received(#stomp_frame{command = <<"ACK">>, headers = Headers}, State) ->
     Id = header(<<"id">>, Headers),
     Action = fun(State0) -> 
-                 maybe_send_receipt(receipt_id(Headers), State0),
+                 _ = maybe_send_receipt(receipt_id(Headers), State0),
                  ack(Id, State0) 
              end,
     case header(<<"transaction">>, Headers) of
@@ -176,7 +175,7 @@ received(#stomp_frame{command = <<"ACK">>, headers = Headers}, State) ->
 received(#stomp_frame{command = <<"NACK">>, headers = Headers}, State) ->
     Id = header(<<"id">>, Headers),
     Action = fun(State0) -> 
-                 maybe_send_receipt(receipt_id(Headers), State0),
+                 _ = maybe_send_receipt(receipt_id(Headers), State0),
                  nack(Id, State0) 
              end,
     case header(<<"transaction">>, Headers) of
@@ -226,7 +225,7 @@ received(#stomp_frame{command = <<"ABORT">>, headers = Headers}, State) ->
     end;
 
 received(#stomp_frame{command = <<"DISCONNECT">>, headers = Headers}, State) ->
-    maybe_send_receipt(receipt_id(Headers), State),
+    _ = maybe_send_receipt(receipt_id(Headers), State),
     {stop, normal, State}.
 
 send(Msg = #message{topic = Topic, headers = Headers, payload = Payload},

apps/emqx_telemetry/src/emqx_telemetry.erl

@@ -132,6 +132,12 @@ get_telemetry() ->
 %% gen_server callbacks
 %%--------------------------------------------------------------------
 
+%% This is to suppress dialyzer warnings for mnesia:dirty_write and
+%% dirty_read race condition. Given that the init function is not evaluated
+%% concurrently in one node, it should be free of race condition.
+%% Given the chance of having two nodes bootstraping with the write
+%% is very small, it should be safe to ignore.
+-dialyzer([{nowarn_function, [init/1]}]).
 init([Opts]) ->
     State = #state{url = get_value(url, Opts),
                    report_interval = timer:seconds(get_value(report_interval, Opts))},
@@ -409,4 +415,4 @@ module_attributes(Module) ->
 bin(L) when is_list(L) ->
     list_to_binary(L);
 bin(B) when is_binary(B) ->
-    B.
+    B.

apps/emqx_telemetry/src/emqx_telemetry_api.erl

@@ -103,7 +103,7 @@ get_data(_Bindings, _Params) ->
     return(get_telemetry_data()).
 
 enable_telemetry() ->
-    [enable_telemetry(Node) || Node <- ekka_mnesia:running_nodes()], ok.
+    lists:foreach(fun enable_telemetry/1, ekka_mnesia:running_nodes()).
 
 enable_telemetry(Node) when Node =:= node() ->
     emqx_telemetry:enable();
@@ -111,7 +111,7 @@ enable_telemetry(Node) ->
     rpc_call(Node, ?MODULE, enable_telemetry, [Node]).
 
 disable_telemetry() ->
-    [disable_telemetry(Node) || Node <- ekka_mnesia:running_nodes()], ok.
+    lists:foreach(fun disable_telemetry/1, ekka_mnesia:running_nodes()).
 
 disable_telemetry(Node) when Node =:= node() ->
     emqx_telemetry:disable();
@@ -128,4 +128,4 @@ rpc_call(Node, Module, Fun, Args) ->
     case rpc:call(Node, Module, Fun, Args) of
         {badrpc, Reason} -> {error, Reason};
         Result -> Result
-    end.
+    end.

rebar.config

@@ -9,9 +9,9 @@
 {minimum_otp_vsn, "21.3"}.
 {edoc_opts, [{preprocess,true}]}.
 {erl_opts, [warn_unused_vars,warn_shadow_vars,warn_unused_import,
-            warn_obsolete_guard,no_debug_info,compressed]}.
+            warn_obsolete_guard,compressed]}.
 
-{overrides,[{add,[{erl_opts,[no_debug_info,compressed,deterministic,
+{overrides,[{add,[{erl_opts,[compressed,deterministic,
                              {parse_transform,mod_vsn}]}]}
            ,{add,[{extra_src_dirs, [{"etc", [{recursive,true}]}]}]}
            ]}.
@@ -46,7 +46,7 @@
     , {minirest, {git, "https://github.com/emqx/minirest", {tag, "0.3.2"}}}
     , {ecpool, {git, "https://github.com/emqx/ecpool", {tag, "0.5.0"}}}
     , {replayq, {git, "https://github.com/emqx/replayq", {tag, "v0.2.0"}}}
-    , {pbkdf2, {git, "https://github.com/emqx/erlang-pbkdf2.git", {branch, "2.0.3"}}}
+    , {pbkdf2, {git, "https://github.com/emqx/erlang-pbkdf2.git", {branch, "2.0.4"}}}
     , {emqtt, {git, "https://github.com/emqx/emqtt", {tag, "1.2.3"}}}
     , {rulesql, {git, "https://github.com/emqx/rulesql", {tag, "0.1.2"}}}
     , {getopt, "1.0.1"}

rebar.config.erl

@@ -34,12 +34,18 @@ test_deps() ->
 
 profiles() ->
     [ {'emqx',          [ {relx, relx('emqx')}
+                        , {erl_opts, [no_debug_info]}
                         ]}
     , {'emqx-pkg',      [ {relx, relx('emqx-pkg')}
+                        , {erl_opts, [no_debug_info]}
                         ]}
     , {'emqx-edge',     [ {relx, relx('emqx-edge')}
+                        , {erl_opts, [no_debug_info]}
                         ]}
     , {'emqx-edge-pkg', [ {relx, relx('emqx-edge-pkg')}
+                        , {erl_opts, [no_debug_info]}
+                        ]}
+    , {check,           [ {erl_opts, [debug_info]}
                         ]}
     , {test,            [ {deps, test_deps()}
                         , {erl_opts, [debug_info]}

src/emqx.erl

@@ -86,7 +86,7 @@ restart(ConfFile) ->
     reload_config(ConfFile),
     shutdown(),
     ok = application:stop(mnesia),
-    application:start(mnesia),
+    _ = application:start(mnesia),
     reboot().
 
 %% @doc Stop emqx application.
@@ -184,7 +184,7 @@ hook(HookPoint, Action, InitArgs) when is_list(InitArgs) ->
 hook(HookPoint, Action, Filter, Priority) ->
     emqx_hooks:add(HookPoint, Action, Filter, Priority).
 
--spec(unhook(emqx_hooks:hookpoint(), function() | {module(), atom()}) -> ok).
+-spec(unhook(emqx_hooks:hookpoint(), fun() | {module(), atom()}) -> ok).
 unhook(HookPoint, Action) ->
     emqx_hooks:del(HookPoint, Action).
 
@@ -205,8 +205,8 @@ shutdown() ->
 
 shutdown(Reason) ->
     ?LOG(critical, "emqx shutdown for ~s", [Reason]),
-    emqx_alarm_handler:unload(),
-    emqx_plugins:unload(),
+    _ = emqx_alarm_handler:unload(),
+    _ = emqx_plugins:unload(),
     lists:foreach(fun application:stop/1, [emqx, ekka, cowboy, ranch, esockd, gproc]).
 
 reboot() ->

src/emqx_acl_cache.erl

@@ -107,9 +107,7 @@ put_acl_cache(PubSub, Topic, AclResult) ->
 %% delete all the acl entries
 -spec(empty_acl_cache() -> ok).
 empty_acl_cache() ->
-    map_acl_cache(fun({CacheK, _CacheV}) ->
-            erlang:erase(CacheK)
-        end),
+    foreach_acl_cache(fun({CacheK, _CacheV}) -> erlang:erase(CacheK) end),
     set_cache_size(0),
     keys_queue_set(queue:new()).
 
@@ -139,9 +137,13 @@ get_cache_size() ->
 
 dump_acl_cache() ->
     map_acl_cache(fun(Cache) -> Cache end).
+
 map_acl_cache(Fun) ->
     [Fun(R) || R = {{SubPub, _T}, _Acl} <- get(), SubPub =:= publish
                                            orelse SubPub =:= subscribe].
+foreach_acl_cache(Fun) ->
+    _ = map_acl_cache(Fun),
+    ok.
 
 %%--------------------------------------------------------------------
 %% Internal functions

src/emqx_alarm.erl

@@ -165,6 +165,10 @@ init([Opts]) ->
                                     size_limit = SizeLimit,
                                     validity_period = ValidityPeriod})}.
 
+%% suppress dialyzer warning due to dirty read/write race condition.
+%% TODO: change from dirty_read/write to transactional.
+%% TODO: handle mnesia write errors.
+-dialyzer([{nowarn_function, [handle_call/3]}]).
 handle_call({activate_alarm, Name, Details}, _From, State = #state{actions = Actions}) ->
     case mnesia:dirty_read(?ACTIVATED_ALARM, Name) of
         [#activated_alarm{name = Name}] ->
@@ -211,7 +215,7 @@ handle_call({deactivate_alarm, Name}, _From, State = #state{actions = Actions,
     end;
 
 handle_call(delete_all_deactivated_alarms, _From, State) ->
-    mnesia:clear_table(?DEACTIVATED_ALARM),
+    clear_table(?DEACTIVATED_ALARM),
     {reply, ok, State};
 
 handle_call({get_alarms, all}, _From, State) ->
@@ -266,7 +270,17 @@ deactivate_all_alarms() ->
                                                             message = Message,
                                                             deactivate_at = erlang:system_time(microsecond)})
                   end, ets:tab2list(?ACTIVATED_ALARM)),
-    mnesia:clear_table(?ACTIVATED_ALARM).
+    clear_table(?ACTIVATED_ALARM).
+
+%% Delete all records from the given table, ignore result.
+clear_table(TableName) ->
+    case mnesia:clear_table(TableName) of
+        {aborted, Reason} ->
+            ?LOG(warning, "Faile to clear table ~p reason: ~p",
+                 [TableName, Reason]);
+        {atomic, ok} ->
+            ok
+    end.
 
 ensure_delete_timer(State = #state{validity_period = ValidityPeriod}) ->
     State#state{timer = emqx_misc:start_timer(ValidityPeriod div 1, delete_expired_deactivated_alarm)}.
@@ -299,7 +313,8 @@ do_actions(Operation, Alarm, [publish | More]) ->
     {ok, Payload} = encode_to_json(Alarm),
     Message = emqx_message:make(?MODULE, 0, Topic, Payload, #{sys => true},
                   #{properties => #{'Content-Type' => <<"application/json">>}}),
-    emqx_broker:safe_publish(Message),
+    %% TODO log failed publishes
+    _ = emqx_broker:safe_publish(Message),
     do_actions(Operation, Alarm, More).
 
 encode_to_json(Alarm) ->

src/emqx_alarm_handler.erl

@@ -85,4 +85,4 @@ handle_call(_Query, State) ->
 terminate(swap, _State) ->
     {emqx_alarm_handler, []};
 terminate(_, _) ->
-    ok.
+    ok.

src/emqx_app.erl

@@ -34,18 +34,18 @@ start(_Type, _Args) ->
     {ok, Sup} = emqx_sup:start_link(),
     ok = emqx_modules:load(),
     ok = emqx_plugins:init(),
-    emqx_plugins:load(),
+    _ = emqx_plugins:load(),
     emqx_boot:is_enabled(listeners)
       andalso (ok = emqx_listeners:start()),
     start_autocluster(),
     register(emqx, self()),
-    emqx_alarm_handler:load(),
+    ok = emqx_alarm_handler:load(),
     print_vsn(),
     {ok, Sup}.
 
 -spec(stop(State :: term()) -> term()).
 stop(_State) ->
-    emqx_alarm_handler:unload(),
+    ok = emqx_alarm_handler:unload(),
     emqx_boot:is_enabled(listeners)
       andalso emqx_listeners:stop(),
     emqx_modules:unload().

src/emqx_broker.erl

@@ -465,7 +465,8 @@ handle_cast({subscribe, Topic}, State) ->
 handle_cast({unsubscribed, Topic}, State) ->
     case ets:member(?SUBSCRIBER, Topic) of
         false ->
-            _ = emqx_router:do_delete_route(Topic);
+            _ = emqx_router:do_delete_route(Topic),
+            ok;
         true -> ok
     end,
     {noreply, State};

src/emqx_channel.erl

@@ -1554,15 +1554,20 @@ mabye_publish_will_msg(Channel = #channel{will_msg = undefined}) ->
     Channel;
 mabye_publish_will_msg(Channel = #channel{will_msg = WillMsg}) ->
     case will_delay_interval(WillMsg) of
-        0 -> publish_will_msg(WillMsg),
-             Channel#channel{will_msg = undefined};
-        I -> ensure_timer(will_timer, timer:seconds(I), Channel)
+        0 ->
+            ok = publish_will_msg(WillMsg),
+            Channel#channel{will_msg = undefined};
+        I ->
+            ensure_timer(will_timer, timer:seconds(I), Channel)
     end.
 
 will_delay_interval(WillMsg) ->
     maps:get('Will-Delay-Interval', emqx_message:get_header(properties, WillMsg), 0).
 
-publish_will_msg(Msg) -> emqx_broker:publish(Msg).
+publish_will_msg(Msg) ->
+    %% TODO check if we should discard result here
+    _ = emqx_broker:publish(Msg),
+    ok.
 
 %%--------------------------------------------------------------------
 %% Disconnect Reason

src/emqx_connection.erl

@@ -252,6 +252,7 @@ run_loop(Parent, State = #state{transport = Transport,
             exit_on_sock_error(Reason)
     end.
 
+-spec exit_on_sock_error(any()) -> no_return().
 exit_on_sock_error(Reason) when Reason =:= einval;
                                 Reason =:= enotconn;
                                 Reason =:= closed ->
@@ -343,7 +344,7 @@ handle_msg({'$gen_call', From, Req}, State) ->
 handle_msg({Inet, _Sock, Data}, State) when Inet == tcp; Inet == ssl ->
     ?LOG(debug, "RECV ~0p", [Data]),
     Oct = iolist_size(Data),
-    emqx_pd:inc_counter(incoming_bytes, Oct),
+    inc_counter(incoming_bytes, Oct),
     ok = emqx_metrics:inc('bytes.received', Oct),
     parse_incoming(Data, State);
 
@@ -439,11 +440,12 @@ handle_msg(Msg, State) ->
 %%--------------------------------------------------------------------
 %% Terminate
 
+-spec terminate(any(), state()) -> no_return().
 terminate(Reason, State = #state{channel = Channel}) ->
     ?LOG(debug, "Terminated due to ~p", [Reason]),
     emqx_alarm:deactivate(?ALARM_TCP_CONGEST(Channel)),
     emqx_channel:terminate(Reason, Channel),
-    close_socket(State),
+    _ = close_socket(State),
     exit(Reason).
 
 %%--------------------------------------------------------------------
@@ -611,7 +613,7 @@ serialize_and_inc_stats_fun(#state{serialize = Serialize}) ->
 send(IoData, #state{transport = Transport, socket = Socket, channel = Channel}) ->
     Oct = iolist_size(IoData),
     ok = emqx_metrics:inc('bytes.sent', Oct),
-    emqx_pd:inc_counter(outgoing_bytes, Oct),
+    inc_counter(outgoing_bytes, Oct),
     maybe_warn_congestion(Socket, Transport, Channel),
     case Transport:async_send(Socket, IoData, [nosuspend]) of
         ok -> ok;
@@ -750,23 +752,25 @@ close_socket(State = #state{transport = Transport, socket = Socket}) ->
 
 -compile({inline, [inc_incoming_stats/1]}).
 inc_incoming_stats(Packet = ?PACKET(Type)) ->
-    emqx_pd:inc_counter(recv_pkt, 1),
-    if
-        Type == ?PUBLISH ->
-            emqx_pd:inc_counter(recv_msg, 1),
-            emqx_pd:inc_counter(incoming_pubs, 1);
-        true -> ok
+    inc_counter(recv_pkt, 1),
+    case Type =:= ?PUBLISH of
+        true ->
+            inc_counter(recv_msg, 1),
+            inc_counter(incoming_pubs, 1);
+        false ->
+            ok
     end,
     emqx_metrics:inc_recv(Packet).
 
 -compile({inline, [inc_outgoing_stats/1]}).
 inc_outgoing_stats(Packet = ?PACKET(Type)) ->
-    emqx_pd:inc_counter(send_pkt, 1),
-    if
-        Type == ?PUBLISH ->
-            emqx_pd:inc_counter(send_msg, 1),
-            emqx_pd:inc_counter(outgoing_pubs, 1);
-        true -> ok
+    inc_counter(send_pkt, 1),
+    case Type =:= ?PUBLISH of
+        true ->
+            inc_counter(send_msg, 1),
+            inc_counter(outgoing_pubs, 1);
+        false ->
+            ok
     end,
     emqx_metrics:inc_sent(Packet).
 
@@ -795,6 +799,10 @@ stop(Reason, State) ->
 stop(Reason, Reply, State) ->
     {stop, Reason, Reply, State}.
 
+inc_counter(Key, Inc) ->
+    _ = emqx_pd:inc_counter(Key, Inc),
+    ok.
+
 %%--------------------------------------------------------------------
 %% For CT tests
 %%--------------------------------------------------------------------

src/emqx_hooks.erl

@@ -31,6 +31,7 @@
 -export([ add/2
         , add/3
         , add/4
+        , put/2
         , del/2
         , run/2
         , run_fold/3
@@ -111,6 +112,14 @@ add(HookPoint, Action, Priority) when is_integer(Priority) ->
 add(HookPoint, Action, Filter, Priority) when is_integer(Priority) ->
     add(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).
 
+%% @doc Like add/2, it register a callback, discard 'already_exists' error.
+-spec(put(hookpoint(), action() | #callback{}) -> ok).
+put(HookPoint, Callback) ->
+    case add(HookPoint, Callback) of
+        ok -> ok;
+        {error, already_exists} -> ok
+    end.
+
 %% @doc Unregister a callback.
 -spec(del(hookpoint(), function() | {module(), atom()}) -> ok).
 del(HookPoint, Action) ->

src/emqx_listeners.erl

@@ -124,10 +124,10 @@ restart_listener(tcp, ListenOn, _Options) ->
 restart_listener(Proto, ListenOn, _Options) when Proto == ssl; Proto == tls ->
     esockd:reopen('mqtt:ssl', ListenOn);
 restart_listener(Proto, ListenOn, Options) when Proto == http; Proto == ws ->
-    cowboy:stop_listener(ws_name('mqtt:ws', ListenOn)),
+    _ = cowboy:stop_listener(ws_name('mqtt:ws', ListenOn)),
     start_listener(Proto, ListenOn, Options);
 restart_listener(Proto, ListenOn, Options) when Proto == https; Proto == wss ->
-    cowboy:stop_listener(ws_name('mqtt:wss', ListenOn)),
+    _ = cowboy:stop_listener(ws_name('mqtt:wss', ListenOn)),
     start_listener(Proto, ListenOn, Options);
 restart_listener(Proto, ListenOn, _Opts) ->
     esockd:reopen(Proto, ListenOn).

src/emqx_logger.erl

@@ -268,7 +268,7 @@ set_all_log_handlers_level([], _NewLevel, _NewHanlder) ->
     ok.
 
 rollback([{ID, Level} | List]) ->
-    set_log_handler_level(ID, Level),
+    _ = set_log_handler_level(ID, Level),
     rollback(List);
 rollback([]) -> ok.
 

src/emqx_mod_presence.erl

@@ -38,8 +38,8 @@
 -endif.
 
 load(Env) ->
-    emqx_hooks:add('client.connected',    {?MODULE, on_client_connected, [Env]}),
-    emqx_hooks:add('client.disconnected', {?MODULE, on_client_disconnected, [Env]}).
+    emqx_hooks:put('client.connected',    {?MODULE, on_client_connected, [Env]}),
+    emqx_hooks:put('client.disconnected', {?MODULE, on_client_disconnected, [Env]}).
 
 unload(_Env) ->
     emqx_hooks:del('client.connected',    {?MODULE, on_client_connected}),

src/emqx_mod_rewrite.erl

@@ -45,9 +45,9 @@
 
 load(RawRules) ->
     {PubRules, SubRules} = compile(RawRules),
-    emqx_hooks:add('client.subscribe',   {?MODULE, rewrite_subscribe, [SubRules]}),
-    emqx_hooks:add('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}),
-    emqx_hooks:add('message.publish',    {?MODULE, rewrite_publish, [PubRules]}).
+    emqx_hooks:put('client.subscribe',   {?MODULE, rewrite_subscribe, [SubRules]}),
+    emqx_hooks:put('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}),
+    emqx_hooks:put('message.publish',    {?MODULE, rewrite_publish, [PubRules]}).
 
 rewrite_subscribe(_ClientInfo, _Properties, TopicFilters, Rules) ->
     {ok, [{match_and_rewrite(Topic, Rules), Opts} || {Topic, Opts} <- TopicFilters]}.

src/emqx_mod_sup.erl

@@ -40,11 +40,13 @@
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
+-spec start_child(supervisor:child_spec()) -> ok.
 start_child(ChildSpec) when is_map(ChildSpec) ->
-    supervisor:start_child(?MODULE, ChildSpec).
+    assert_started(supervisor:start_child(?MODULE, ChildSpec)).
 
+-spec start_child(atom(), atom()) -> ok.
 start_child(Mod, Type) when is_atom(Mod) andalso is_atom(Type) ->
-    supervisor:start_child(?MODULE, ?CHILD(Mod, Type)).
+    assert_started(supervisor:start_child(?MODULE, ?CHILD(Mod, Type))).
 
 -spec(stop_child(any()) -> ok | {error, term()}).
 stop_child(ChildId) ->
@@ -61,3 +63,12 @@ init([]) ->
     ok = emqx_tables:new(emqx_modules, [set, public, {write_concurrency, true}]),
     {ok, {{one_for_one, 10, 100}, []}}.
 
+%%--------------------------------------------------------------------
+%% Internal functions
+%%--------------------------------------------------------------------
+
+assert_started({ok, _Pid}) -> ok;
+assert_started({ok, _Pid, _Info}) -> ok;
+assert_started({error, {already_tarted, _Pid}}) -> ok;
+assert_started({error, Reason}) -> erlang:error(Reason).
+

src/emqx_mod_topic_metrics.erl

@@ -102,14 +102,14 @@
 
 load(_Env) ->
     emqx_mod_sup:start_child(?MODULE, worker),
-    emqx:hook('message.publish',   {?MODULE, on_message_publish, []}),
-    emqx:hook('message.dropped',   {?MODULE, on_message_dropped, []}),
-    emqx:hook('message.delivered', {?MODULE, on_message_delivered, []}).
+    emqx_hooks:put('message.publish',   {?MODULE, on_message_publish, []}),
+    emqx_hooks:put('message.dropped',   {?MODULE, on_message_dropped, []}),
+    emqx_hooks:put('message.delivered', {?MODULE, on_message_delivered, []}).
 
 unload(_Env) ->
-    emqx:unhook('message.publish',   {?MODULE, on_message_publish}),
-    emqx:unhook('message.dropped',   {?MODULE, on_message_dropped}),
-    emqx:unhook('message.delivered', {?MODULE, on_message_delivered}),
+    emqx_hooks:del('message.publish',   {?MODULE, on_message_publish}),
+    emqx_hooks:del('message.dropped',   {?MODULE, on_message_dropped}),
+    emqx_hooks:del('message.delivered', {?MODULE, on_message_delivered}),
     emqx_mod_sup:stop_child(?MODULE).
 
 description() ->
@@ -118,7 +118,7 @@ description() ->
 on_message_publish(#message{topic = Topic, qos = QoS}) ->
     case is_registered(Topic) of
         true ->
-            inc(Topic, 'messages.in'),
+            try_inc(Topic, 'messages.in'),
             case QoS of
                 ?QOS_0 -> inc(Topic, 'messages.qos0.in');
                 ?QOS_1 -> inc(Topic, 'messages.qos1.in');
@@ -131,7 +131,7 @@ on_message_publish(#message{topic = Topic, qos = QoS}) ->
 on_message_delivered(_, #message{topic = Topic, qos = QoS}) ->
     case is_registered(Topic) of
         true ->
-            inc(Topic, 'messages.out'),
+            try_inc(Topic, 'messages.out'),
             case QoS of
                 ?QOS_0 -> inc(Topic, 'messages.qos0.out');
                 ?QOS_1 -> inc(Topic, 'messages.qos1.out');
@@ -155,6 +155,10 @@ start_link() ->
 stop() ->
     gen_server:stop(?MODULE).
 
+try_inc(Topic, Metric) ->
+    _ = inc(Topic, Metric),
+    ok.
+
 inc(Topic, Metric) ->
     inc(Topic, Metric, 1).
 

src/emqx_modules.erl

@@ -77,14 +77,17 @@ unload(ModuleName) ->
             unload_module(ModuleName, true)
     end.
 
+-spec(reload(module()) -> ok | ignore | {error, any()}).
 reload(emqx_mod_acl_internal) ->
     Modules = emqx:get_env(modules, []),
     Env = proplists:get_value(emqx_mod_acl_internal, Modules, undefined),
     case emqx_mod_acl_internal:reload(Env) of
         ok ->
-            ?LOG(info, "Reload ~s module successfully.", [emqx_mod_acl_internal]);
+            ?LOG(info, "Reload ~s module successfully.", [emqx_mod_acl_internal]),
+            ok;
         {error, Error} ->
-            ?LOG(error, "Reload module ~s failed, cannot start for ~0p", [emqx_mod_acl_internal, Error])
+            ?LOG(error, "Reload module ~s failed, cannot start for ~0p", [emqx_mod_acl_internal, Error]),
+            {error, Error}
     end;
 reload(_) ->
     ignore.
@@ -125,7 +128,7 @@ load_module(ModuleName, Persistent) ->
     case ModuleName:load(Env) of
         ok ->
             ets:insert(?MODULE, {ModuleName, true}),
-            write_loaded(Persistent),
+            ok = write_loaded(Persistent),
             ?LOG(info, "Load ~s module successfully.", [ModuleName]);
         {error, Error} ->
             ?LOG(error, "Load module ~s failed, cannot load for ~0p", [ModuleName, Error]),
@@ -152,7 +155,7 @@ unload_module(ModuleName, Persistent) ->
     case ModuleName:unload(Env) of
         ok ->
             ets:insert(?MODULE, {ModuleName, false}),
-            write_loaded(Persistent),
+            ok = write_loaded(Persistent),
             ?LOG(info, "Unload ~s module successfully.", [ModuleName]);
         {error, Error} ->
             ?LOG(error, "Unload module ~s failed, cannot unload for ~0p", [ModuleName, Error])
@@ -164,6 +167,6 @@ write_loaded(true) ->
         ok -> ok;
         {error, Error} ->
             ?LOG(error, "Write File ~p Error: ~p", [FilePath, Error]),
-            {error, Error}
+            ok
     end;
 write_loaded(false) -> ok.

src/emqx_plugins.erl

@@ -59,13 +59,13 @@ init() ->
     end.
 
 %% @doc Load all plugins when the broker started.
--spec(load() -> list() | {error, term()}).
+-spec(load() -> ok | ignore | {error, term()}).
 load() ->
     load_expand_plugins(),
     case emqx:get_env(plugins_loaded_file) of
         undefined -> ignore; %% No plugins available
         File ->
-            ensure_file(File),
+            _ = ensure_file(File),
             with_loaded_file(File, fun(Names) -> load_plugins(Names, false) end)
     end.
 
@@ -103,7 +103,7 @@ unload(PluginName) when is_atom(PluginName) ->
             ?LOG(error, "Plugin ~s is not started", [PluginName]),
             {error, not_started};
         {_, _} ->
-            unload_plugin(PluginName, true)            
+            unload_plugin(PluginName, true)
     end.
 
 reload(PluginName) when is_atom(PluginName)->
@@ -165,7 +165,7 @@ load_expand_plugins() ->
 load_expand_plugin(PluginDir) ->
     init_expand_plugin_config(PluginDir),
     Ebin = filename:join([PluginDir, "ebin"]),
-    code:add_patha(Ebin),
+    _ = code:add_patha(Ebin),
     Modules = filelib:wildcard(filename:join([Ebin, "*.beam"])),
     lists:foreach(fun(Mod) ->
         Module = list_to_atom(filename:basename(Mod, ".beam")),
@@ -246,7 +246,7 @@ apply_configs([{App, Config} | More]) ->
 
 %% Stop plugins
 stop_plugins(Names) ->
-    [stop_app(App) || App <- Names],
+    _ = [stop_app(App) || App <- Names],
     ok.
 
 plugin(AppName, Type) ->
@@ -287,7 +287,7 @@ start_app(App, SuccFun) ->
         {ok, Started} ->
             ?LOG(info, "Started plugins: ~p", [Started]),
             ?LOG(info, "Load plugin ~s successfully", [App]),
-            SuccFun(App),
+            _ = SuccFun(App),
             ok;
         {error, {ErrApp, Reason}} ->
             ?LOG(error, "Load plugin ~s failed, cannot start plugin ~s for ~0p", [App, ErrApp, Reason]),
@@ -297,7 +297,7 @@ start_app(App, SuccFun) ->
 unload_plugin(App, Persistent) ->
     case stop_app(App) of
         ok ->
-            plugin_unloaded(App, Persistent), ok;
+            _ = plugin_unloaded(App, Persistent), ok;
         {error, Reason} ->
             {error, Reason}
     end.

src/emqx_sys.erl

@@ -151,16 +151,16 @@ handle_cast(Msg, State) ->
     {noreply, State}.
 
 handle_info({timeout, TRef, heartbeat}, State = #state{heartbeat = TRef}) ->
-    publish(uptime, iolist_to_binary(uptime(State))),
-    publish(datetime, iolist_to_binary(datetime())),
+    publish_any(uptime, iolist_to_binary(uptime(State))),
+    publish_any(datetime, iolist_to_binary(datetime())),
     {noreply, heartbeat(State)};
 
 handle_info({timeout, TRef, tick}, State = #state{ticker = TRef, version = Version, sysdescr = Descr}) ->
-    publish(version, Version),
-    publish(sysdescr, Descr),
-    publish(brokers, ekka_mnesia:running_nodes()),
-    publish(stats, emqx_stats:getstats()),
-    publish(metrics, emqx_metrics:all()),
+    publish_any(version, Version),
+    publish_any(sysdescr, Descr),
+    publish_any(brokers, ekka_mnesia:running_nodes()),
+    publish_any(stats, emqx_stats:getstats()),
+    publish_any(metrics, emqx_metrics:all()),
     {noreply, tick(State), hibernate};
 
 handle_info(Info, State) ->
@@ -192,6 +192,10 @@ uptime(hours, H) ->
 uptime(days, D) ->
     [integer_to_list(D), " days, "].
 
+publish_any(Name, Value) ->
+    _ = publish(Name, Value),
+    ok.
+
 publish(uptime, Uptime) ->
     safe_publish(systop(uptime), Uptime);
 publish(datetime, Datetime) ->

src/emqx_sys_mon.erl

@@ -55,7 +55,7 @@ start_link(Opts) ->
 %%--------------------------------------------------------------------
 
 init([Opts]) ->
-    erlang:system_monitor(self(), parse_opt(Opts)),
+    _ = erlang:system_monitor(self(), parse_opt(Opts)),
     emqx_logger:set_proc_metadata(#{sysmon => true}),
 
     %% Monitor cluster partition event
@@ -174,7 +174,7 @@ suppress(Key, SuccFun, State = #{events := Events}) ->
         true ->
             {noreply, State};
         false ->
-            SuccFun(),
+            _ = SuccFun(),
             {noreply, State#{events := [Key|Events]}}
     end.
 

src/emqx_types.erl

@@ -113,18 +113,18 @@
                       peername := peername(),
                       peercert := nossl | undefined | esockd_peercert:peercert(),
                       conn_mod := module(),
-                      proto_name := binary(),
-                      proto_ver := ver(),
-                      clean_start := boolean(),
-                      clientid := clientid(),
-                      username := username(),
-                      conn_props := properties(),
-                      connected := boolean(),
-                      connected_at := non_neg_integer(),
+                      proto_name => binary(),
+                      proto_ver => ver(),
+                      clean_start => boolean(),
+                      clientid => clientid(),
+                      username => username(),
+                      conn_props => properties(),
+                      connected => boolean(),
+                      connected_at => non_neg_integer(),
                       disconnected_at => non_neg_integer(),
-                      keepalive := 0..16#FFFF,
-                      receive_maximum := non_neg_integer(),
-                      expiry_interval := non_neg_integer(),
+                      keepalive => 0..16#FFFF,
+                      receive_maximum => non_neg_integer(),
+                      expiry_interval => non_neg_integer(),
                       atom() => term()
                      }).
 -type(clientinfo() :: #{zone         := zone(),
@@ -148,7 +148,8 @@
 -type(username() :: maybe(binary())).
 -type(password() :: maybe(binary())).
 -type(peerhost() :: inet:ip_address()).
--type(peername() :: {inet:ip_address(), inet:port_number()}).
+-type(peername() :: {inet:ip_address(), inet:port_number()}
+                  | inet:returned_non_ip_address()).
 -type(protocol() :: mqtt | 'mqtt-sn' | coap | lwm2m | stomp | none | atom()).
 -type(auth_result() :: success
                      | client_identifier_not_valid

src/emqx_ws_connection.erl

@@ -63,7 +63,7 @@
           %% Simulate the active_n opt
           active_n :: pos_integer(),
           %% MQTT Piggyback
-          mqtt_piggyback :: single | multiple, 
+          mqtt_piggyback :: single | multiple,
           %% Limiter
           limiter :: maybe(emqx_limiter:limiter()),
           %% Limit Timer
@@ -535,7 +535,7 @@ handle_outgoing(Packets, State = #state{active_n = ActiveN, mqtt_piggyback = MQT
                      postpone({check_gc, Stats}, State);
                  false -> State
              end,
-    
+
     {case MQTTPiggyback of
          single -> [{binary, IoData}];
          multiple -> lists:map(fun(Bin) -> {binary, Bin} end, IoData)
@@ -568,35 +568,38 @@ serialize_and_inc_stats_fun(#state{serialize = Serialize}) ->
           ]}).
 
 inc_recv_stats(Cnt, Oct) ->
-    emqx_pd:inc_counter(incoming_bytes, Oct),
-    emqx_pd:inc_counter(recv_cnt, Cnt),
-    emqx_pd:inc_counter(recv_oct, Oct),
+    inc_counter(incoming_bytes, Oct),
+    inc_counter(recv_cnt, Cnt),
+    inc_counter(recv_oct, Oct),
     emqx_metrics:inc('bytes.received', Oct).
 
 inc_incoming_stats(Packet = ?PACKET(Type)) ->
-    emqx_pd:inc_counter(recv_pkt, 1),
+    _ = emqx_pd:inc_counter(recv_pkt, 1),
     if Type == ?PUBLISH ->
-           emqx_pd:inc_counter(recv_msg, 1),
-           emqx_pd:inc_counter(incoming_pubs, 1);
+           inc_counter(recv_msg, 1),
+           inc_counter(incoming_pubs, 1);
        true -> ok
     end,
     emqx_metrics:inc_recv(Packet).
 
 inc_outgoing_stats(Packet = ?PACKET(Type)) ->
-    emqx_pd:inc_counter(send_pkt, 1),
+    _ = emqx_pd:inc_counter(send_pkt, 1),
     if Type == ?PUBLISH ->
-           emqx_pd:inc_counter(send_msg, 1),
-           emqx_pd:inc_counter(outgoing_pubs, 1);
+           inc_counter(send_msg, 1),
+           inc_counter(outgoing_pubs, 1);
        true -> ok
     end,
     emqx_metrics:inc_sent(Packet).
 
 inc_sent_stats(Cnt, Oct) ->
-    emqx_pd:inc_counter(outgoing_bytes, Oct),
-    emqx_pd:inc_counter(send_cnt, Cnt),
-    emqx_pd:inc_counter(send_oct, Oct),
+    inc_counter(outgoing_bytes, Oct),
+    inc_counter(send_cnt, Cnt),
+    inc_counter(send_oct, Oct),
     emqx_metrics:inc('bytes.sent', Oct).
 
+inc_counter(Name, Value) ->
+    _ = emqx_pd:inc_counter(Name, Value),
+    ok.
 %%--------------------------------------------------------------------
 %% Helper functions
 %%--------------------------------------------------------------------