feat(retainer): CLI to list and clean retained messages

apps/emqx_retainer/src/emqx_retainer.erl

@@ -41,7 +41,8 @@
     delete/1,
     page_read/3,
     post_config_update/5,
-    stats_fun/0
+    stats_fun/0,
+    retained_count/0
 ]).
 
 %% gen_server callbacks
@@ -152,6 +153,9 @@ clean() ->
 delete(Topic) ->
     call({?FUNCTION_NAME, Topic}).
 
+retained_count() ->
+    call(?FUNCTION_NAME).
+
 page_read(Topic, Page, Limit) ->
     call({?FUNCTION_NAME, Topic, Page, Limit}).
 

apps/emqx_retainer/src/emqx_retainer_mnesia.erl

@@ -24,6 +24,7 @@
 -include_lib("stdlib/include/ms_transform.hrl").
 -include_lib("stdlib/include/qlc.hrl").
 
+%% emqx_retainer callbacks
 -export([
     delete_message/2,
     store_retained/2,
@@ -35,6 +36,9 @@
     size/1
 ]).
 
+%% Management API:
+-export([topics/0]).
+
 -export([create_resource/1]).
 
 -export([reindex/2, reindex_status/0]).
@@ -54,6 +58,13 @@
 -define(REINDEX_BATCH_SIZE, 1000).
 -define(REINDEX_DISPATCH_WAIT, 30000).
 
+%%--------------------------------------------------------------------
+%% Management API
+%%--------------------------------------------------------------------
+
+topics() ->
+    [emqx_topic:join(I) || I <- mnesia:dirty_all_keys(?TAB_MESSAGE)].
+
 %%--------------------------------------------------------------------
 %% emqx_retainer callbacks
 %%--------------------------------------------------------------------

apps/emqx_retainer/src/emqx_retainer_mnesia_cli.erl

@@ -31,6 +31,15 @@
 load() ->
     ok = emqx_ctl:register_command(retainer, {?MODULE, retainer}, []).
 
+retainer(["info"]) ->
+    ?PRINT("Number of retained messages: ~p~n", [emqx_retainer:retained_count()]);
+retainer(["topics"]) ->
+    [?PRINT("~ts~n", [I]) || I <- emqx_retainer_mnesia:topics()],
+    ok;
+retainer(["clean", Topic]) ->
+    emqx_retainer:delete(list_to_binary(Topic));
+retainer(["clean"]) ->
+    emqx_retainer:clean();
 retainer(["reindex", "status"]) ->
     case emqx_retainer_mnesia:reindex_status() of
         true ->
@@ -66,6 +75,10 @@ retainer(["reindex", "start", ForceParam]) ->
 retainer(_) ->
     emqx_ctl:usage(
         [
+            {"retainer info", "Show the count of retained messages"},
+            {"retainer topics", "Show all topics of retained messages"},
+            {"retainer clean", "Clean all retained messages"},
+            {"retainer clean <Topic>", "Clean retained messages by the specified topic filter"},
             {"retainer reindex status", "Show reindex status"},
             {"retainer reindex start [force]",
                 "Generate new retainer topic indices config settings.\n"

apps/emqx_retainer/test/emqx_retainer_cli_SUITE.erl

@@ -38,6 +38,18 @@ end_per_suite(_Config) ->
 t_reindex_status(_Config) ->
     ok = emqx_retainer_mnesia_cli:retainer(["reindex", "status"]).
 
+t_info(_Config) ->
+    ok = emqx_retainer_mnesia_cli:retainer(["info"]).
+
+t_topics(_Config) ->
+    ok = emqx_retainer_mnesia_cli:retainer(["topics"]).
+
+t_clean(_Config) ->
+    ok = emqx_retainer_mnesia_cli:retainer(["clean"]).
+
+t_topic(_Config) ->
+    ok = emqx_retainer_mnesia_cli:retainer(["clean", "foo/bar"]).
+
 t_reindex(_Config) ->
     {ok, C} = emqtt:start_link([{clean_start, true}, {proto_ver, v5}]),
     {ok, _} = emqtt:connect(C),