Make it possible to configure WebSocket options such as compression

While at it, correctly configure connection inactivity
timeout with modern Cowboy versions.

Closes #34.
References rabbitmq/rabbitmq-web-stomp#89.

[#161053821]

deps/rabbitmq_web_mqtt/priv/schema/rabbitmq_web_mqtt.schema

@@ -67,5 +67,38 @@
     [{datatype, integer}]}.
 {mapping, "web_mqtt.cowboy_opts.max_request_line_length", "rabbitmq_web_mqtt.cowboy_opts.max_request_line_length",
     [{datatype, integer}]}.
-{mapping, "web_mqtt.cowboy_opts.timeout", "rabbitmq_web_mqtt.cowboy_opts.timeout",
+{mapping, "web_mqtt.cowboy_opts.timeout", "rabbitmq_web_mqtt.cowboy_opts.idle_timeout",
     [{datatype, integer}]}.
+
+%% backwards compatibility
+{mapping, "web_mqtt.cowboy_opts.timeout",      "rabbitmq_web_mqtt.cowboy_opts.idle_timeout",
+    [{datatype, integer}, {validators, ["non_negative_integer"]}]
+}.
+%% recent Cowboy versions have several timeout settings
+{mapping, "web_mqtt.cowboy_opts.idle_timeout", "rabbitmq_web_mqtt.cowboy_opts.idle_timeout",
+    [{datatype, integer}]
+}.
+
+{translation,
+    "rabbitmq_web_mqtt.cowboy_opts.idle_timeout",
+    fun(Conf) ->
+        case cuttlefish:conf_get("web_mqtt.cowboy_opts.timeout", Conf, undefined) of
+            Value when is_integer(Value) ->
+                Value;
+            undefined ->
+                case cuttlefish:conf_get("web_mqtt.cowboy_opts.idle_timeout", Conf, undefined) of
+                    undefined -> cuttlefish:unset();
+                    Value     -> Value
+                end
+        end
+    end
+}.
+
+{mapping, "web_mqtt.ws_opts.compress", "rabbitmq_web_mqtt.cowboy_ws_opts.compress",
+    [{datatype, {enum, [true, false]}}]}.
+{mapping, "web_mqtt.ws_opts.max_frame_size", "rabbitmq_web_mqtt.cowboy_ws_opts.max_frame_size",
+    [{datatype, integer}, {validators, ["non_negative_integer"]}]
+}.
+{mapping, "web_mqtt.ws_opts.idle_timeout", "rabbitmq_web_mqtt.cowboy_ws_opts.idle_timeout",
+    [{datatype, integer}, {validators, ["non_negative_integer"]}]
+}.

deps/rabbitmq_web_mqtt/src/rabbit_web_mqtt_app.erl

@@ -45,21 +45,27 @@ init([]) -> {ok, {{one_for_one, 1, 5}, []}}.
 %%----------------------------------------------------------------------------
 
 mqtt_init() ->
-    CowboyOpts0 = get_env(cowboy_opts, []),
+    CowboyOpts0 = maps:from_list(get_env(cowboy_opts, [])),
 
     Routes = cowboy_router:compile([{'_', [
         {get_env(ws_path, "/ws"), rabbit_web_mqtt_handler, []}
     ]}]),
-    CowboyOpts = maps:from_list([
-        {env, #{dispatch => Routes}},
-        {middlewares, [cowboy_router, rabbit_web_mqtt_middleware, cowboy_handler]}
-    |CowboyOpts0]),
-
+    CowboyOpts = CowboyOpts0#{env         => #{dispatch => Routes},
+                              middlewares => [cowboy_router, rabbit_web_mqtt_middleware, cowboy_handler]},
     {TCPConf, IpStr, Port} = get_tcp_conf(),
 
-    {ok, _} = ranch:start_listener(web_mqtt, get_env(num_tcp_acceptors, 10),
+    case ranch:start_listener(web_mqtt, get_env(num_tcp_acceptors, 10),
         ranch_tcp, TCPConf,
-        rabbit_web_mqtt_connection_sup, CowboyOpts),
+        rabbit_web_mqtt_connection_sup, CowboyOpts) of
+        {ok, _}                       -> ok;
+        {error, {already_started, _}} -> ok;
+        {error, Err}                  ->
+            rabbit_log_connection:error(
+                "Failed to start a WebSocket (HTTP) listener. Error: ~p,"
+                " listener settings: ~p~n",
+                [Err, TCPConf]),
+            throw(Err)
+    end,
     listener_started('http/web-mqtt', TCPConf),
     rabbit_log:info("rabbit_web_mqtt: listening for HTTP connections on ~s:~w~n",
                     [IpStr, Port]),

deps/rabbitmq_web_mqtt/src/rabbit_web_mqtt_handler.erl

@@ -46,13 +46,14 @@ init(Req, Opts) ->
                 SecWsProtocol ->
                     cowboy_req:set_resp_header(<<"sec-websocket-protocol">>, SecWsProtocol, Req)
             end,
+            WsOpts = proplists:get_value(ws_opts, Opts, #{}),
             {cowboy_websocket, Req2, #state{
                 conn_name     = ConnStr,
                 keepalive     = {none, none},
                 keepalive_sup = KeepaliveSup,
                 parse_state   = rabbit_mqtt_frame:initial_state(),
                 socket        = Sock
-            }};
+            }, WsOpts};
         _ ->
             {stop, Req}
     end.

deps/rabbitmq_web_mqtt/test/config_schema_SUITE_data/rabbitmq_web_mqtt.snippets

@@ -49,7 +49,47 @@
     [{ws_path, "/rmq/ws"}]}],
   [rabbitmq_web_mqtt]},
 
+ %%
+ %% Cowboy options
+ %%
+
  {cowboy_max_keepalive,
   "web_mqtt.cowboy_opts.max_keepalive = 10",
   [{rabbitmq_web_mqtt,[{cowboy_opts,[{max_keepalive, 10}]}]}],
-  [rabbitmq_web_mqtt]}].
+  [rabbitmq_web_mqtt]},
+
+ {cowboy_timeout,
+  "web_mqtt.cowboy_opts.timeout = 10000",
+  [{rabbitmq_web_mqtt,[{cowboy_opts,[{idle_timeout, 10000}]}]}],
+  [rabbitmq_web_mqtt]},
+
+ {cowboy_idle_timeout,
+  "web_mqtt.cowboy_opts.idle_timeout = 10000",
+  [{rabbitmq_web_mqtt,[{cowboy_opts,[{idle_timeout, 10000}]}]}],
+  [rabbitmq_web_mqtt]},
+
+ %%
+ %% Cowboy WebSocket options
+ %%
+
+{ws_opts_compress_true,
+  "web_mqtt.ws_opts.compress = true",
+  [{rabbitmq_web_mqtt,[{cowboy_ws_opts,[{compress, true}]}]}],
+  [rabbitmq_web_mqtt]},
+
+{ws_opts_compress_false,
+  "web_mqtt.ws_opts.compress = false",
+  [{rabbitmq_web_mqtt,[{cowboy_ws_opts,[{compress, false}]}]}],
+  [rabbitmq_web_mqtt]},
+
+{ws_opts_max_frame_size,
+  "web_mqtt.ws_opts.max_frame_size = 8000",
+  [{rabbitmq_web_mqtt,[{cowboy_ws_opts,[{max_frame_size, 8000}]}]}],
+  [rabbitmq_web_mqtt]},
+
+{ws_idle_timeout,
+  "web_mqtt.ws_opts.idle_timeout = 10000",
+  [{rabbitmq_web_mqtt,[{cowboy_ws_opts,[{idle_timeout, 10000}]}]}],
+  [rabbitmq_web_mqtt]}
+].
+