Merge pull request #2114 from rabbitmq/consume-events-command

Consume events command

1 files changed, 206 insertions, 0 deletions

diff --git a/src/rabbit_event_consumer.erl b/src/rabbit_event_consumer.erl
new file mode 100644
index 0000000000..d0159000f6
--- /dev/null
+++ b/src/rabbit_event_consumer.erl
@@ -0,0 +1,206 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License
+%% at https://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is GoPivotal, Inc.
+%% Copyright (c) 2007-2019 Pivotal Software, Inc.  All rights reserved.
+%%
+
+-module(rabbit_event_consumer).
+
+-include_lib("rabbit_common/include/rabbit.hrl").
+
+-export([register/4]).
+-export([init/1, handle_call/2, handle_event/2, handle_info/2,
+         terminate/2, code_change/3]).
+
+-record(state, {pid, ref, monitor, pattern}).
+
+%%----------------------------------------------------------------------------
+
+register(Pid, Ref, Duration, Pattern) ->
+    case gen_event:add_handler(rabbit_event, ?MODULE, [Pid, Ref, Duration, Pattern]) of
+        ok ->
+            {ok, Ref};
+        Error ->
+            Error
+    end.
+
+%%----------------------------------------------------------------------------
+
+init([Pid, Ref, Duration, Pattern]) ->
+    MRef = erlang:monitor(process, Pid),
+    case Duration of
+        infinity -> infinity;
+        _        -> erlang:send_after(Duration * 1000, self(), rabbit_event_consumer_timeout)
+    end,
+    {ok, #state{pid = Pid, ref = Ref, monitor = MRef, pattern = Pattern}}.
+
+handle_call(_Request, State) -> {ok, not_understood, State}.
+
+handle_event(#event{type      = Type,
+                    props     = Props,
+                    timestamp = TS,
+                    reference = none}, #state{pid = Pid,
+                                              ref = Ref,
+                                              pattern = Pattern} = State) ->
+    case key(Type) of
+        ignore -> ok;
+        Key    -> case re:run(Key, Pattern, [{capture, none}]) of
+                      match ->
+                          Data = [{'event', Key}] ++
+                              fmt_proplist([{'timestamp_in_ms', TS} | Props]),
+                          Pid ! {Ref, Data, confinue};
+                      _ ->
+                          ok
+                  end
+    end,
+    {ok, State};
+handle_event(_Event, State) ->
+    {ok, State}.
+
+handle_info({'DOWN', MRef, _, _, _}, #state{monitor = MRef}) ->
+    remove_handler;
+handle_info(rabbit_event_consumer_timeout, #state{pid = Pid, ref = Ref}) ->
+    Pid ! {Ref, <<>>, finished},
+    remove_handler;
+handle_info(_Info, State) ->
+    {ok, State}.
+
+terminate(_Arg, #state{monitor = MRef}) ->
+    erlang:demonitor(MRef),
+    ok.
+
+code_change(_OldVsn, State, _Extra) -> {ok, State}.
+
+%%----------------------------------------------------------------------------
+
+%% pattern matching is way more efficient that the string operations,
+%% let's use all the keys we're aware of to speed up the handler.
+%% Any unknown or new one will be processed as before (see last function clause).
+key(queue_deleted) ->
+    <<"queue.deleted">>;
+key(queue_created) ->
+    <<"queue.created">>;
+key(exchange_created) ->
+    <<"exchange.created">>;
+key(exchange_deleted) ->
+    <<"exchange.deleted">>;
+key(binding_created) ->
+    <<"binding.created">>;
+key(connection_created) ->
+    <<"connection.created">>;
+key(connection_closed) ->
+    <<"connection.closed">>;
+key(channel_created) ->
+    <<"channel.created">>;
+key(channel_closed) ->
+    <<"channel.closed">>;
+key(consumer_created) ->
+    <<"consumer.created">>;
+key(consumer_deleted) ->
+    <<"consumer.deleted">>;
+key(queue_stats) ->
+    ignore;
+key(connection_stats) ->
+    ignore;
+key(policy_set) ->
+    <<"policy.set">>;
+key(policy_cleared) ->
+    <<"policy.cleared">>;
+key(parameter_set) ->
+    <<"parameter.set">>;
+key(parameter_cleared) ->
+    <<"parameter.cleared">>;
+key(vhost_created) ->
+    <<"vhost.created">>;
+key(vhost_deleted) ->
+    <<"vhost.deleted">>;
+key(vhost_limits_set) ->
+    <<"vhost.limits.set">>;
+key(vhost_limits_cleared) ->
+    <<"vhost.limits.cleared">>;
+key(user_authentication_success) ->
+    <<"user.authentication.success">>;
+key(user_authentication_failure) ->
+    <<"user.authentication.failure">>;
+key(user_created) ->
+    <<"user.created">>;
+key(user_deleted) ->
+    <<"user.deleted">>;
+key(user_password_changed) ->
+    <<"user.password.changed">>;
+key(user_password_cleared) ->
+    <<"user.password.cleared">>;
+key(user_tags_set) ->
+    <<"user.tags.set">>;
+key(permission_created) ->
+    <<"permission.created">>;
+key(permission_deleted) ->
+    <<"permission.deleted">>;
+key(topic_permission_created) ->
+    <<"topic.permission.created">>;
+key(topic_permission_deleted) ->
+    <<"topic.permission.deleted">>;
+key(alarm_set) ->
+    <<"alarm.set">>;
+key(alarm_cleared) ->
+    <<"alarm.cleared">>;
+key(shovel_worker_status) ->
+    <<"shovel.worker.status">>;
+key(shovel_worker_removed) ->
+    <<"shovel.worker.removed">>;
+key(federation_link_status) ->
+    <<"federation.link.status">>;
+key(federation_link_removed) ->
+    <<"federation.link.removed">>;
+key(S) ->
+    case string:tokens(atom_to_list(S), "_") of
+        [_, "stats"] -> ignore;
+        Tokens       -> list_to_binary(string:join(Tokens, "."))
+    end.
+
+fmt_proplist(Props) ->
+    lists:foldl(fun({K, V}, Acc) ->
+                        case fmt(K, V) of
+                            L when is_list(L) -> lists:append(L, Acc);
+                            T -> [T | Acc]
+                        end
+                end, [], Props).
+
+fmt(K, #resource{virtual_host = VHost, 
+                 name         = Name}) -> [{K,           Name},
+                                           {'vhost', VHost}];
+fmt(K, true)                 -> {K, true};
+fmt(K, false)                -> {K, false};
+fmt(K, V) when is_atom(V)    -> {K, atom_to_binary(V, utf8)};
+fmt(K, V) when is_integer(V) -> {K, V};
+fmt(K, V) when is_number(V)  -> {K, V};
+fmt(K, V) when is_binary(V)  -> {K, V};
+fmt(K, [{_, _}|_] = Vs)      -> {K, fmt_proplist(Vs)};
+fmt(K, Vs) when is_list(Vs)  -> {K,  [fmt(V) || V <- Vs]};
+fmt(K, V) when is_pid(V)     -> {K, list_to_binary(rabbit_misc:pid_to_string(V))};
+fmt(K, V)                    -> {K,
+                                 list_to_binary(
+                                   rabbit_misc:format("~1000000000p", [V]))}.
+
+%% Exactly the same as fmt/2, duplicated only for performance issues
+fmt(true)                 -> true;
+fmt(false)                -> false;
+fmt(V) when is_atom(V)    -> atom_to_binary(V, utf8);
+fmt(V) when is_integer(V) -> V;
+fmt(V) when is_number(V)  -> V;
+fmt(V) when is_binary(V)  -> V;
+fmt([{_, _}|_] = Vs)      -> fmt_proplist(Vs);
+fmt(Vs) when is_list(Vs)  -> [fmt(V) || V <- Vs];
+fmt(V) when is_pid(V)     -> list_to_binary(rabbit_misc:pid_to_string(V));
+fmt(V)                    -> list_to_binary(
+                                rabbit_misc:format("~1000000000p", [V])).