Accept multiple protocols in protocol listener health check

This updates the health check for protocol listeners to accept a set of
protocols, comma-separated. The check only returns 200 OK when all
requested protocols have active listeners.

Author: the-mikedavis

deps/rabbitmq_management/priv/www/api/index.html

@@ -1202,10 +1202,12 @@ <h2>Reference</h2>
         <td></td>
         <td></td>
         <td></td>
-        <td class="path">/api/health/checks/protocol-listener/<i>protocol</i></td>
+        <td class="path">/api/health/checks/protocol-listener/<i>protocols</i></td>
         <td>
-          Responds a 200 OK if there is an active listener for the given protocol,
-          otherwise responds with a 503 Service Unavailable. Valid protocol names are: amqp091, amqp10, mqtt, stomp, web-mqtt, web-stomp.
+          Responds a 200 OK if all given protocols have active listeners,
+          otherwise responds with a 503 Service Unavailable. Multiple protocols
+          may be provided by separating the names with commas. Valid protocol
+          names are: amqp091, amqp10, mqtt, stomp, web-mqtt, web-stomp.
         </td>
       </tr>
       <tr>

deps/rabbitmq_management/src/rabbit_mgmt_dispatcher.erl

@@ -200,7 +200,7 @@ dispatcher() ->
      {"/health/checks/metadata-store/initialized/with-data",   rabbit_mgmt_wm_health_check_metadata_store_initialized_with_data, []},
      {"/health/checks/certificate-expiration/:within/:unit",   rabbit_mgmt_wm_health_check_certificate_expiration, []},
      {"/health/checks/port-listener/:port",                    rabbit_mgmt_wm_health_check_port_listener, []},
-     {"/health/checks/protocol-listener/:protocol",            rabbit_mgmt_wm_health_check_protocol_listener, []},
+     {"/health/checks/protocol-listener/:protocols",           rabbit_mgmt_wm_health_check_protocol_listener, []},
      {"/health/checks/virtual-hosts",                          rabbit_mgmt_wm_health_check_virtual_hosts, []},
      {"/health/checks/quorum-queues-without-elected-leaders/all-vhosts/",    rabbit_mgmt_wm_health_check_quorum_queues_without_elected_leaders_across_all_vhosts, []},
      {"/health/checks/quorum-queues-without-elected-leaders/vhost/:vhost/",  rabbit_mgmt_wm_health_check_quorum_queues_without_elected_leaders, []},

deps/rabbitmq_management/src/rabbit_mgmt_wm_health_check_protocol_listener.erl

@@ -27,40 +27,46 @@ content_types_provided(ReqData, Context) ->
    {rabbit_mgmt_util:responder_map(to_json), ReqData, Context}.
 
 resource_exists(ReqData, Context) ->
-    {case protocol(ReqData) of
+    {case protocols(ReqData) of
          none -> false;
          _ -> true
      end, ReqData, Context}.
 
 to_json(ReqData, Context) ->
-    Protocol = normalize_protocol(protocol(ReqData)),
+    Protocols = string:split(protocols(ReqData), ",", all),
+    RequestedProtocols = sets:from_list(
+                           [normalize_protocol(P) || P <- Protocols],
+                           [{version, 2}]),
     Listeners = rabbit_networking:node_listeners(node()),
-    ProtoListeners = [L || #listener{protocol = P} = L <- Listeners, atom_to_list(P) == Protocol],
-    case ProtoListeners of
+    ActiveProtocols = sets:from_list(
+                        [atom_to_list(P) || #listener{protocol = P} <- Listeners],
+                        [{version, 2}]),
+    MissingProtocols = sets:to_list(sets:subtract(RequestedProtocols, ActiveProtocols)),
+    case MissingProtocols of
         [] ->
-            Msg = <<"No active listener">>,
-            failure(Msg, Protocol, [P || #listener{protocol = P} <- Listeners], ReqData, Context);
+            Body = #{status    => ok,
+                     protocols => [list_to_binary(P) || P <- sets:to_list(ActiveProtocols)]},
+            rabbit_mgmt_util:reply(Body, ReqData, Context);
         _ ->
-            Body = #{status   => ok,
-                     protocol => list_to_binary(Protocol)},
-            rabbit_mgmt_util:reply(Body, ReqData, Context)
+            Msg = <<"No active listener">>,
+            failure(Msg, MissingProtocols, sets:to_list(ActiveProtocols), ReqData, Context)
     end.
 
 failure(Message, Missing, Protocols, ReqData, Context) ->
     Body = #{
         status    => failed,
         reason    => Message,
-        missing   => list_to_binary(Missing),
-        protocols => Protocols
+        missing   => [list_to_binary(P) || P <- Missing],
+        protocols => [list_to_binary(P) || P <- Protocols]
     },
     {Response, ReqData1, Context1} = rabbit_mgmt_util:reply(Body, ReqData, Context),
     {stop, cowboy_req:reply(503, #{}, Response, ReqData1), Context1}.
 
 is_authorized(ReqData, Context) ->
     rabbit_mgmt_util:is_authorized(ReqData, Context).
 
-protocol(ReqData) ->
-    rabbit_mgmt_util:id(protocol, ReqData).
+protocols(ReqData) ->
+    rabbit_mgmt_util:id(protocols, ReqData).
 
 normalize_protocol(Protocol) ->
     case string:lowercase(binary_to_list(Protocol)) of

deps/rabbitmq_management/test/rabbit_mgmt_http_health_checks_SUITE.erl

@@ -384,7 +384,7 @@ protocol_listener_test(Config) ->
     Body0 = http_get_failed(Config, "/health/checks/protocol-listener/mqtt"),
     ?assertEqual(<<"failed">>, maps:get(<<"status">>, Body0)),
     ?assertEqual(true, maps:is_key(<<"reason">>, Body0)),
-    ?assertEqual(<<"mqtt">>, maps:get(<<"missing">>, Body0)),
+    ?assertEqual([<<"mqtt">>], maps:get(<<"missing">>, Body0)),
     ?assert(lists:member(<<"http">>, maps:get(<<"protocols">>, Body0))),
     ?assert(lists:member(<<"clustering">>, maps:get(<<"protocols">>, Body0))),
     ?assert(lists:member(<<"amqp">>, maps:get(<<"protocols">>, Body0))),
@@ -394,6 +394,14 @@ protocol_listener_test(Config) ->
     http_get_failed(Config, "/health/checks/protocol-listener/stomp"),
     http_get_failed(Config, "/health/checks/protocol-listener/stomp1.0"),
 
+    %% Multiple protocols may be supplied. The health check only returns OK if
+    %% all requested protocols are available.
+    Body1 = http_get_failed(Config, "/health/checks/protocol-listener/amqp,mqtt"),
+    ?assertEqual(<<"failed">>, maps:get(<<"status">>, Body1)),
+    ?assertEqual(true, maps:is_key(<<"reason">>, Body1)),
+    ?assert(lists:member(<<"mqtt">>, maps:get(<<"missing">>, Body1))),
+    ?assert(lists:member(<<"amqp">>, maps:get(<<"protocols">>, Body1))),
+
     passed.
 
 port_listener_test(Config) ->