feat(prometheus): Support swagger prometheus API

apps/emqx/src/emqx_schema.erl

@@ -93,6 +93,7 @@ includes() ->
     , "emqx_management"
     , "emqx_dashboard"
     , "emqx_gateway"
+    , "emqx_prometheus"
     ].
 -endif.
 

apps/emqx_prometheus/etc/emqx_prometheus.conf

@@ -4,4 +4,5 @@
 emqx_prometheus:{
     push_gateway_server: "http://127.0.0.1:9091"
     interval: "15s"
+    enable: true
 }

apps/emqx_prometheus/include/emqx_prometheus.hrl

@@ -0,0 +1 @@
+-define(APP, emqx_prometheus).

apps/emqx_prometheus/src/emqx_prometheus.erl

@@ -25,12 +25,6 @@
 -include_lib("prometheus/include/prometheus.hrl").
 -include_lib("prometheus/include/prometheus_model.hrl").
 
--rest_api(#{name   => stats,
-            method => 'GET',
-            path   => "/emqx_prometheus",
-            func   => stats,
-            descr  => "Get emqx all stats info"
-           }).
 
 -import(prometheus_model_helpers,
         [ create_mf/5
@@ -38,11 +32,8 @@
         , counter_metric/1
         ]).
 
-%% REST APIs
--export([stats/2]).
-
 %% APIs
--export([start_link/2]).
+-export([start_link/1]).
 
 %% gen_server callbacks
 -export([ init/1
@@ -59,6 +50,8 @@
         , collect_metrics/2
         ]).
 
+-export([collect/1]).
+
 -define(C(K, L), proplists:get_value(K, L, 0)).
 
 -define(TIMER_MSG, '#interval').
@@ -69,25 +62,17 @@
 %% APIs
 %%--------------------------------------------------------------------
 
-start_link(PushGateway, Interval) ->
-    gen_server:start_link({local, ?MODULE}, ?MODULE, [PushGateway, Interval], []).
-
-%%--------------------------------------------------------------------
-%% REST APIs
-
-stats(_Bindings, Params) ->
-    collect(proplists:get_value(<<"type">>, Params, <<"json">>)).
+start_link(Opts) ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [Opts], []).
 
 %%--------------------------------------------------------------------
 %% gen_server callbacks
 %%--------------------------------------------------------------------
 
-init([undefined, Interval]) ->
-    {ok, #state{interval = Interval}};
-
-init([PushGateway, Interval]) ->
-    Ref = erlang:start_timer(Interval, self(), ?TIMER_MSG),
-    {ok, #state{timer = Ref, push_gateway = PushGateway, interval = Interval}}.
+init([Opts]) ->
+    Interval = maps:get(interval, Opts),
+    PushGateway = maps:get(push_gateway_server, Opts),
+    {ok, ensure_timer(#state{push_gateway = PushGateway, interval = Interval})}.
 
 handle_call(_Msg, _From, State) ->
     {noreply, State}.
@@ -95,12 +80,12 @@ handle_call(_Msg, _From, State) ->
 handle_cast(_Msg, State) ->
     {noreply, State}.
 
-handle_info({timeout, R, ?TIMER_MSG}, S = #state{interval=I, timer=R, push_gateway=Uri}) ->
+handle_info({timeout, R, ?TIMER_MSG}, State = #state{timer=R, push_gateway=Uri}) ->
     [Name, Ip] = string:tokens(atom_to_list(node()), "@"),
     Url = lists:concat([Uri, "/metrics/job/", Name, "/instance/",Name, "~", Ip]),
     Data = prometheus_text_format:format(),
     httpc:request(post, {Url, [], "text/plain", Data}, [{autoredirect, true}], []),
-    {noreply, S#state{timer = erlang:start_timer(I, self(), ?TIMER_MSG)}};
+    {noreply, ensure_timer(State)};
 
 handle_info(_Msg, State) ->
     {noreply, State}.
@@ -111,6 +96,8 @@ code_change(_OldVsn, State, _Extra) ->
 terminate(_Reason, _State) ->
     ok.
 
+ensure_timer(State = #state{interval = Interval}) ->
+    State#state{timer = emqx_misc:start_timer(Interval, ?TIMER_MSG)}.
 %%--------------------------------------------------------------------
 %% prometheus callbacks
 %%--------------------------------------------------------------------
@@ -138,18 +125,16 @@ collect(<<"json">>) ->
     Metrics = emqx_metrics:all(),
     Stats = emqx_stats:getstats(),
     VMData = emqx_vm_data(),
-    Data = [{stats, [collect_stats(Name, Stats) || Name <- emqx_stats()]},
-            {metrics, [collect_stats(Name, VMData) || Name <- emqx_vm()]},
-            {packets, [collect_stats(Name, Metrics) || Name <- emqx_metrics_packets()]},
-            {messages, [collect_stats(Name, Metrics) || Name <- emqx_metrics_messages()]},
-            {delivery, [collect_stats(Name, Metrics) || Name <- emqx_metrics_delivery()]},
-            {client, [collect_stats(Name, Metrics) || Name <- emqx_metrics_client()]},
-            {session, [collect_stats(Name, Metrics) || Name <- emqx_metrics_session()]}],
-    return({ok, Data});
+    [{stats, [collect_stats(Name, Stats) || Name <- emqx_stats()]},
+     {metrics, [collect_stats(Name, VMData) || Name <- emqx_vm()]},
+     {packets, [collect_stats(Name, Metrics) || Name <- emqx_metrics_packets()]},
+     {messages, [collect_stats(Name, Metrics) || Name <- emqx_metrics_messages()]},
+     {delivery, [collect_stats(Name, Metrics) || Name <- emqx_metrics_delivery()]},
+     {client, [collect_stats(Name, Metrics) || Name <- emqx_metrics_client()]},
+     {session, [collect_stats(Name, Metrics) || Name <- emqx_metrics_session()]}];
 
 collect(<<"prometheus">>) ->
-    Data = prometheus_text_format:format(),
-    {ok, #{<<"content-type">> => <<"text/plain">>}, Data}.
+    prometheus_text_format:format().
 
 %% @private
 collect_stats(Name, Stats) ->
@@ -608,7 +593,3 @@ emqx_cluster_data() ->
     #{running_nodes := Running, stopped_nodes := Stopped} = ekka_mnesia:cluster_info(),
     [{nodes_running, length(Running)},
      {nodes_stopped, length(Stopped)}].
-
-%% TODO: V5 API
-return(_) ->
-    ok.

apps/emqx_prometheus/src/emqx_prometheus_api.erl

@@ -0,0 +1,138 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_prometheus_api).
+
+-behaviour(minirest_api).
+
+-include("emqx_prometheus.hrl").
+
+-import(emqx_mgmt_util, [ response_schema/1
+                        , response_schema/2
+                        , request_body_schema/1
+                        ]).
+
+-export([api_spec/0]).
+
+-export([ prometheus/2
+        % , stats/2
+        ]).
+
+api_spec() ->
+    {[prometheus_api()], schemas()}.
+
+schemas() ->
+    [#{prometheus => #{
+        type => object,
+        properties => #{
+            push_gateway_server => #{
+                type => string,
+                description => <<"prometheus PushGateway Server">>,
+                example => get_raw(<<"push_gateway_server">>, <<"http://127.0.0.1:9091">>)},
+            interval => #{
+                type => string,
+                description => <<"Interval">>,
+                example => get_raw(<<"interval">>, <<"15s">>)},
+            enable => #{
+                type => boolean,
+                description => <<"Prometheus status">>,
+                example => get_raw(<<"enable">>, false)}
+        }
+    }}].
+
+prometheus_api() ->
+    Metadata = #{
+        get => #{
+            description => <<"Get Prometheus info">>,
+            responses => #{
+                <<"200">> => response_schema(prometheus)
+            }
+        },
+        put => #{
+            description => <<"Update Prometheus">>,
+            'requestBody' => request_body_schema(prometheus),
+            responses => #{
+                <<"200">> =>
+                    response_schema(<<"Update Prometheus successfully">>),
+                <<"400">> =>
+                    response_schema(<<"Bad Request">>, #{
+                        type => object,
+                        properties => #{
+                            message => #{type => string},
+                            code => #{type => string}
+                        }
+                    })
+            }
+        }
+    },
+    {"/prometheus", Metadata, prometheus}.
+
+% prometheus_data_api() ->
+%     Metadata = #{
+%         get => #{
+%             description => <<"Get Prometheus Data">>,
+%             parameters => [#{
+%                 name => format_type,
+%                 in => path,
+%                 schema => #{type => string}
+%             }],
+%             responses => #{
+%                 <<"200">> =>
+%                     response_schema(<<"Update Prometheus successfully">>),
+%                 <<"400">> =>
+%                     response_schema(<<"Bad Request">>, #{
+%                         type => object,
+%                         properties => #{
+%                             message => #{type => string},
+%                             code => #{type => string}
+%                         }
+%                     })
+%             }
+%         }
+%     },
+%     {"/prometheus/stats", Metadata, stats}.
+
+prometheus(get, _Request) ->
+    Response = emqx_config:get_raw([<<"emqx_prometheus">>], #{}),
+    {200, Response};
+
+prometheus(put, Request) ->
+    {ok, Body, _} = cowboy_req:read_body(Request),
+    Params = emqx_json:decode(Body, [return_maps]),
+    Enable = maps:get(<<"enable">>, Params),
+    ok = emqx_config:update([?APP], Params),
+    enable_prometheus(Enable).
+
+% stats(_Bindings, Params) ->
+%     Type = proplists:get_value(<<"format_type">>, Params, <<"json">>),
+%     Data = emqx_prometheus:collect(Type),
+%     case Type of
+%         <<"json">> ->
+%             {ok, Data};
+%         <<"prometheus">> ->
+%             {ok, #{<<"content-type">> => <<"text/plain">>}, Data}
+%     end.
+
+enable_prometheus(true) ->
+    ok = emqx_prometheus_sup:stop_child(?APP),
+    emqx_prometheus_sup:start_child(?APP, emqx_config:get([?APP], #{})),
+    {200};
+enable_prometheus(false) ->
+    _ = emqx_prometheus_sup:stop_child(?APP),
+    {200}.
+
+get_raw(Key, Def) ->
+    emqx_config:get_raw([<<"emqx_prometheus">>] ++ [Key], Def).

apps/emqx_prometheus/src/emqx_prometheus_app.erl

@@ -18,20 +18,25 @@
 
 -behaviour(application).
 
--emqx_plugin(?MODULE).
+-include("emqx_prometheus.hrl").
 
 %% Application callbacks
 -export([ start/2
         , stop/1
         ]).
 
--define(APP, emqx_prometheus).
-
 start(_StartType, _StartArgs) ->
-    PushGateway = emqx_config:get([?APP, push_gateway_server], undefined),
-    Interval = emqx_config:get([?APP, interval], 15000),
-    emqx_prometheus_sup:start_link(PushGateway, Interval).
+    {ok, Sup} = emqx_prometheus_sup:start_link(),
+    maybe_enable_prometheus(),
+    {ok, Sup}.
 
 stop(_State) ->
     ok.
 
+maybe_enable_prometheus() ->
+    case emqx_config:get([?APP, enable], false) of
+        true ->
+            emqx_prometheus_sup:start_child(?APP, emqx_config:get([?APP], #{}));
+        false ->
+            ok
+    end.

apps/emqx_prometheus/src/emqx_prometheus_schema.erl

@@ -27,4 +27,5 @@ structs() -> ["emqx_prometheus"].
 fields("emqx_prometheus") ->
     [ {push_gateway_server, emqx_schema:t(string())}
     , {interval, emqx_schema:t(emqx_schema:duration_ms(), undefined, "15s")}
+    , {enable, emqx_schema:t(boolean(), undefined, false)}
     ].

apps/emqx_prometheus/src/emqx_prometheus_sup.erl

@@ -18,19 +18,48 @@
 
 -behaviour(supervisor).
 
--export([start_link/2]).
+-export([ start_link/0
+        , start_child/1
+        , start_child/2
+        , stop_child/1
+        ]).
 
 -export([init/1]).
 
-start_link(PushGateway, Interval) ->
-    supervisor:start_link({local, ?MODULE}, ?MODULE, [PushGateway, Interval]).
+%% Helper macro for declaring children of supervisor
+-define(CHILD(Mod, Opts), #{id => Mod,
+                            start => {Mod, start_link, [Opts]},
+                            restart => permanent,
+                            shutdown => 5000,
+                            type => worker,
+                            modules => [Mod]}).
 
-init([PushGateway, Interval]) ->
-    {ok, {#{strategy => one_for_one, intensity => 10, period => 100},
-          [#{id       => emqx_prometheus,
-             start    => {emqx_prometheus, start_link, [PushGateway, Interval]},
-             restart  => permanent,
-             shutdown => 5000,
-             type     => worker,
-             modules  => [emqx_prometheus]}]}}.
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
+-spec start_child(supervisor:child_spec()) -> ok.
+start_child(ChildSpec) when is_map(ChildSpec) ->
+    assert_started(supervisor:start_child(?MODULE, ChildSpec)).
+
+-spec start_child(atom(), map()) -> ok.
+start_child(Mod, Opts) when is_atom(Mod) andalso is_map(Opts) ->
+    assert_started(supervisor:start_child(?MODULE, ?CHILD(Mod, Opts))).
+
+-spec(stop_child(any()) -> ok | {error, term()}).
+stop_child(ChildId) ->
+    case supervisor:terminate_child(?MODULE, ChildId) of
+        ok -> supervisor:delete_child(?MODULE, ChildId);
+        Error -> Error
+    end.
+
+init([]) ->
+    {ok, {{one_for_one, 10, 3600}, []}}.
+
+%%--------------------------------------------------------------------
+%% 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).

apps/emqx_statsd/src/emqx_statsd_api.erl

@@ -99,7 +99,7 @@ enable_statsd(true) ->
     emqx_statsd_sup:start_child(?APP, emqx_config:get([?APP], #{})),
     {200};
 enable_statsd(false) ->
-    ok = emqx_statsd_sup:stop_child(?APP),
+    _ = emqx_statsd_sup:stop_child(?APP),
     {200}.
 
 get_raw(Key, Def) ->

apps/emqx_statsd/src/emqx_statsd_app.erl

@@ -34,7 +34,7 @@ stop(_) ->
 maybe_enable_statsd() ->
     case emqx_config:get([?APP, enable], false) of
         true ->
-            emqx_statsd_sup:start_child(emqx_statsd, emqx_config:get([?APP], #{}));
+            emqx_statsd_sup:start_child(?APP, emqx_config:get([?APP], #{}));
         false ->
             ok
     end.

rebar.config.erl

@@ -272,6 +272,7 @@ relx_apps(ReleaseType) ->
     , emqx_dashboard
     , emqx_retainer
     , emqx_statsd
+    , emqx_prometheus
     ]
     ++ [quicer || is_quicer_supported()]
     ++ [emqx_license || is_enterprise()]