1 package Catalyst::Engine::Stomp;
3 extends 'Catalyst::Engine::Embeddable';
7 use List::MoreUtils qw/ uniq /;
11 has connection => (is => 'rw', isa => 'Net::Stomp');
12 has conn_desc => (is => 'rw', isa => 'Str');
16 Catalyst::Engine::Stomp - write message handling apps with Catalyst.
23 $ENV{CATALYST_ENGINE} = 'Stomp';
24 require Catalyst::Engine::Stomp;
27 MyApp->config->{Engine::Stomp} =
29 hostname => '127.0.0.1',
34 # In a controller, or controller base class:
35 use base qw/ Catalyst::Controller::MessageDriven /;
37 # then create actions, which map as message types
38 sub testaction : Local {
41 # Reply with a minimal response message
42 my $response = { type => 'testaction_response' };
43 $c->stash->{response} = $response;
46 # The default serialization is YAML, but this configuration
47 # may be overridden in your controller:
49 'default' => 'text/x-yaml',
50 'stash_key' => 'rest',
51 'map' => { 'text/x-yaml' => 'YAML' },
56 Write a Catalyst app connected to a Stomp messagebroker, not HTTP. You
57 need a controller that understands messaging, as well as this engine.
59 This is single-threaded and single process - you need to run multiple
60 instances of this engine to get concurrency, and configure your broker
61 to load-balance across multiple consumers of the same queue.
63 Controllers are mapped to Stomp queues, and a controller base class is
64 provided, Catalyst::Controller::MessageDriven, which implements
65 YAML-serialized messages, mapping a top-level YAML "type" key to
72 App entry point. Starts a loop listening for messages.
77 my ($self, $app, $oneshot) = @_;
79 die 'No Engine::Stomp configuration found'
80 unless ref $app->config->{'Engine::Stomp'} eq 'HASH';
82 # list the path namespaces that will be mapped as queues.
84 # this is known to use the deprecated
85 # Dispatcher->action_hash() method, but there doesn't appear
86 # to be another way to get the relevant strings out.
88 # http://github.com/rafl/catalyst-runtime/commit/5de163f4963d9dbb41d7311ca6f17314091b7af3#L2R644
94 values %{$app->dispatcher->action_hash};
97 my %template = %{$app->config->{'Engine::Stomp'}};
98 $self->connection(Net::Stomp->new(\%template));
99 $self->connection->connect();
100 $self->conn_desc($template{hostname}.':'.$template{port});
102 # subscribe, with client ack.
103 foreach my $queue (@queues) {
104 my $queue_name = "/queue/$queue";
105 $self->connection->subscribe({
106 destination => $queue_name,
113 my $frame = $self->connection->receive_frame();
114 $self->handle_stomp_frame($app, $frame);
115 last if $ENV{ENGINE_ONESHOT};
120 =head2 prepare_request
122 Overridden to add the source broker to the request, in place of the
127 sub prepare_request {
128 my ($self, $c, $req, $res_ref) = @_;
130 $self->next::method(@_);
131 $c->req->address($self->conn_desc);
134 =head2 finalize_headers
136 Overridden to dump out any errors encountered, since you won't get a
137 "debugging" message as for HTTP.
141 sub finalize_headers {
143 my $error = join "\n", @{$c->error};
145 $c->log->debug($error);
147 return $self->next::method($c);
150 =head2 handle_stomp_frame
152 Dispatch according to Stomp frame type.
156 sub handle_stomp_frame {
157 my ($self, $app, $frame) = @_;
159 my $command = $frame->command();
160 if ($command eq 'MESSAGE') {
161 $self->handle_stomp_message($app, $frame);
163 elsif ($command eq 'ERROR') {
164 $self->handle_stomp_error($app, $frame);
167 $app->log->debug("Got unknown Stomp command: $command");
171 =head2 handle_stomp_message
173 Dispatch a Stomp message into the Catalyst app.
177 sub handle_stomp_message {
178 my ($self, $app, $frame) = @_;
180 # queue -> controller
181 my $queue = $frame->headers->{destination};
182 my ($controller) = $queue =~ m!^/queue/(.*)$!;
185 my $config = $app->config->{'Engine::Stomp'};
186 my $url = 'stomp://'.$config->{hostname}.':'.$config->{port}.'/'.$controller;
187 my $req = HTTP::Request->new(POST => $url);
188 $req->content($frame->body);
189 $req->content_length(length $frame->body);
193 $app->handle_request($req, \$response);
196 my $reply_queue = '/remote-temp-queue/' . ($response->headers->header('X-Reply-Address'));
197 $self->connection->send({ destination => $reply_queue, body => $response->content });
199 # ack the message off the queue now we've replied
200 $self->connection->ack( { frame => $frame } );
203 =head2 handle_stomp_error
205 Log any Stomp error frames we receive.
209 sub handle_stomp_error {
210 my ($self, $app, $frame) = @_;
212 my $error = $frame->headers->{message};
213 $app->log->debug("Got Stomp error: $error");
216 __PACKAGE__->meta->make_immutable;