Truncate message payloads in the web UI so as not to crash the browser...

deps/rabbitmq_management/priv/www-api/help.html

@@ -327,13 +327,15 @@ Content-Length: 0</pre>
         <td>
           Get messages from a queue. (This is not an HTTP GET as it
           will alter the state of the queue.) You should post a body looking like:
-          <pre>{"count": 5, "requeue": true}</pre>
+          <pre>{"count": 5, "requeue": true, "truncate": 50000}</pre>
           to control the (maximum) number of messages you get and
           whether those messages are requeued. If <code>requeue</code>
           is false the messages will be removed from the queue. If
           requeue is true they will be requeued - but their position
           in the queue may change and their <code>redelivered</code>
-          flag will be set.
+          flag will be set. <code>truncate</code> is optional - if
+          present it will truncate the message payload if it is larger
+          than the size given (in bytes).
         </td>
       </tr>
       <tr>

deps/rabbitmq_management/priv/www/js/help.js

@@ -60,10 +60,11 @@ HELP = {
       network connections.',
 
     'message-get-requeue':
-      'Clicking "Get Message(s)" will consume messages from the queue. \
+      '<p>Clicking "Get Message(s)" will consume messages from the queue. \
       If requeue is set the message will be re-added to the queue, \
-      but ordering will not be preserved and "redelivered" will be set.<br/> \
-      If requeue is not set messages will be removed from the queue.',
+      but ordering will not be preserved and "redelivered" will be set.</p> \
+      <p>If requeue is not set messages will be removed from the queue.</p> \
+      <p>Furthermore, message payloads will be truncated to 50000 bytes.</p>',
 
     'message-publish-headers':
       'Headers can have any name. Only long string headers can be set here.',

deps/rabbitmq_management/priv/www/js/tmpl/queue.ejs

@@ -134,6 +134,7 @@
     <form action="#/queues/get" method="post">
       <input type="hidden" name="vhost" value="<%= queue.vhost %>"/>
       <input type="hidden" name="name" value="<%= queue.name %>"/>
+      <input type="hidden" name="truncate" value="50000"/>
       <table class="form">
         <tr>
           <th><label>Requeue:</label></th>

deps/rabbitmq_management/src/rabbit_mgmt_wm_queue_get.erl

@@ -45,7 +45,7 @@ do_it(ReqData, Context) ->
     Q = rabbit_mgmt_util:id(queue, ReqData),
     rabbit_mgmt_util:with_decode(
       [requeue, count, encoding], ReqData, Context,
-      fun([RequeueBin, CountBin, EncBin], _) ->
+      fun([RequeueBin, CountBin, EncBin], Body) ->
               rabbit_mgmt_util:with_channel(
                 VHost, ReqData, Context,
                 fun (Ch) ->
@@ -58,22 +58,27 @@ do_it(ReqData, Context) ->
                                                          {bad_encoding,
                                                           EncBin}})
                               end,
+                        Trunc = case proplists:get_value(truncate, Body) of
+                                    undefined -> none;
+                                    TruncBin  -> rabbit_mgmt_util:parse_int(
+                                                   TruncBin)
+                                end,
                         rabbit_mgmt_util:reply(
-                          basic_gets(Count, Ch, Q, NoAck, Enc),
+                          basic_gets(Count, Ch, Q, NoAck, Enc, Trunc),
                           ReqData, Context)
                 end)
       end).
 
-basic_gets(0, _, _, _, _) ->
+basic_gets(0, _, _, _, _, _) ->
     [];
 
-basic_gets(Count, Ch, Q, NoAck, Enc) ->
-    case basic_get(Ch, Q, NoAck, Enc) of
+basic_gets(Count, Ch, Q, NoAck, Enc, Trunc) ->
+    case basic_get(Ch, Q, NoAck, Enc, Trunc) of
         none -> [];
-        M    -> [M | basic_gets(Count - 1, Ch, Q, NoAck, Enc)]
+        M    -> [M | basic_gets(Count - 1, Ch, Q, NoAck, Enc, Trunc)]
     end.
 
-basic_get(Ch, Q, NoAck, Enc) ->
+basic_get(Ch, Q, NoAck, Enc, Trunc) ->
     case amqp_channel:call(Ch, #'basic.get'{queue = Q,
                                             no_ack = NoAck}) of
         {#'basic.get_ok'{redelivered   = Redelivered,
@@ -87,7 +92,7 @@ basic_get(Ch, Q, NoAck, Enc) ->
              {routing_key,   RoutingKey},
              {message_count, MessageCount},
              {properties,    rabbit_mgmt_format:basic_properties(Props)}] ++
-                payload_part(Payload, Enc);
+                payload_part(maybe_truncate(Payload, Trunc), Enc);
         #'basic.get_empty'{} ->
             none
     end.
@@ -97,6 +102,12 @@ is_authorized(ReqData, Context) ->
 
 %%--------------------------------------------------------------------
 
+maybe_truncate(Payload, none)                         -> Payload;
+maybe_truncate(Payload, Len) when size(Payload) < Len -> Payload;
+maybe_truncate(Payload, Len) ->
+    <<Start:Len/binary, _Rest/binary>> = Payload,
+    Start.
+
 payload_part(Payload, Enc) ->
     {PL, E} = case Enc of
                   auto -> try

deps/rabbitmq_management/test/rabbit_mgmt_test_http.erl

@@ -717,13 +717,14 @@ get_test() ->
                         #amqp_msg{props = #'P_basic'{headers = Headers},
                                   payload = Payload})
               end,
-    Publish(<<"1">>),
-    Publish(<<"2">>),
-    Publish(<<"3">>),
+    Publish(<<"1aaa">>),
+    Publish(<<"2aaa">>),
+    Publish(<<"3aaa">>),
     amqp_connection:close(Conn),
     [Msg] = http_post("/queues/%2f/myqueue/get", [{requeue,  false},
                                                   {count,    1},
-                                                  {encoding, auto}], ?OK),
+                                                  {encoding, auto},
+                                                  {truncate, 1}], ?OK),
     false         = pget(redelivered, Msg),
     <<>>          = pget(exchange,    Msg),
     <<"myqueue">> = pget(routing_key, Msg),
@@ -735,8 +736,8 @@ get_test() ->
     [M2, M3] = http_post("/queues/%2f/myqueue/get", [{requeue,  true},
                                                      {count,    5},
                                                      {encoding, auto}], ?OK),
-    <<"2">> = pget(payload, M2),
-    <<"3">> = pget(payload, M3),
+    <<"2aaa">> = pget(payload, M2),
+    <<"3aaa">> = pget(payload, M3),
     2 = length(http_post("/queues/%2f/myqueue/get", [{requeue,  false},
                                                      {count,    5},
                                                      {encoding, auto}], ?OK)),