fix(retainer): fix that EMQX can't start when the retainer is disabled

apps/emqx_retainer/src/emqx_retainer.erl

@@ -348,16 +348,12 @@ enable_retainer(
     #{context_id := ContextId} = State,
     #{
         msg_clear_interval := ClearInterval,
-        backend := BackendCfg,
-        flow_control := FlowControl
+        backend := BackendCfg
     }
 ) ->
     NewContextId = ContextId + 1,
     Context = create_resource(new_context(NewContextId), BackendCfg),
     load(Context),
-    emqx_limiter_server:add_bucket(
-        ?APP, internal, maps:get(batch_deliver_limiter, FlowControl, undefined)
-    ),
     State#{
         enable := true,
         context_id := NewContextId,
@@ -373,7 +369,6 @@ disable_retainer(
     } = State
 ) ->
     unload(),
-    emqx_limiter_server:del_bucket(?APP, internal),
     ok = close_resource(Context),
     State#{
         enable := false,

apps/emqx_retainer/src/emqx_retainer_app.erl

@@ -18,6 +18,8 @@
 
 -behaviour(application).
 
+-include("emqx_retainer.hrl").
+
 -export([
     start/2,
     stop/1
@@ -25,8 +27,19 @@
 
 start(_Type, _Args) ->
     ok = emqx_retainer_mnesia_cli:load(),
+    init_bucket(),
     emqx_retainer_sup:start_link().
 
 stop(_State) ->
     ok = emqx_retainer_mnesia_cli:unload(),
+    delete_bucket(),
     ok.
+
+init_bucket() ->
+    #{flow_control := FlowControl} = emqx:get_config([retainer]),
+    emqx_limiter_server:add_bucket(
+        ?APP, internal, maps:get(batch_deliver_limiter, FlowControl, undefined)
+    ).
+
+delete_bucket() ->
+    emqx_limiter_server:del_bucket(?APP, internal).