fix: wait for app to boot before starting subscriptions

lib/index.js

@@ -30,7 +30,7 @@ function setupRabbitMqModel(app, settings) {
 module.exports = function loopbackComponentMq(app, settings) {
   settings = settings || {}
 
-  debug('initializing message queue component with settings: %o', settings)
+  debug('initializing message queue component with settings: %O', settings)
 
   // Set up the RabbitMQ model.
   const RabbitMQ = setupRabbitMqModel(app, settings)
@@ -52,25 +52,59 @@ module.exports = function loopbackComponentMq(app, settings) {
     process.exit(1)
   })
 
+  // Determine which queues should be subscribed to.
+  const queuesToSubscribeTo = []
+
+  _.map(settings.topology.queues, queue => {
+    if (queue.subscribe) {
+      queuesToSubscribeTo.push(queue)
+      delete queue.subscribe
+    }
+  })
+
+  // Start subscriptions for a list of queues.
+  function startSubscriptionsForQueues(queues) {
+    queues.forEach(queue => rabbit.startSubscription(queue.name))
+    debug('Started subscriptions for queues: %O', queuesToSubscribeTo)
+  }
+
   // Configure the rabbit topology.
-  rabbit.configure(settings.topology)
-    .then(() => debug('Rabbit topology configured'))
-    .catch(err => {
-      RabbitMQ.log.error('Unable to configure Rabbit topology', err)
-      process.exit(1)
-    })
-
-  const connection = _.get(rabbit, 'configurations.default.connection')
-  const parsedConnectionUri = url.parse(connection.uri)
-  const ampqStatsOptions = {
-    username: connection.user,
-    password: connection.pass,
-    hostname: `${parsedConnectionUri.hostname}:${_.get(settings, 'options.restPort', 15672)}`,
-    protocol: (parsedConnectionUri.protocol === 'amqps') ? 'https' : 'http',
+  function configureRabbit() {
+    return rabbit.configure(settings.topology)
+      .then(() => debug('Rabbit topology configured'))
+      .catch(err => {
+        RabbitMQ.log.error('Unable to configure Rabbit topology', err)
+        process.exit(1)
+      })
   }
 
-  debug('Setting up AmqpStats with options: %o', ampqStatsOptions)
+  // Start subscriptions for a list of queues.
+  function startSubscriptions() {
+    if (app.booting) {
+      return app.on('booted', () => {
+        startSubscriptionsForQueues(queuesToSubscribeTo)
+      })
+    }
+    return startSubscriptionsForQueues(queuesToSubscribeTo)
+  }
+
+  function configureAmqpStats() {
+    const connection = _.get(rabbit, 'configurations.default.connection')
+    const parsedConnectionUri = url.parse(connection.uri)
+    const ampqStatsOptions = {
+      username: connection.user,
+      password: connection.pass,
+      hostname: `${parsedConnectionUri.hostname}:${_.get(settings, 'options.restPort', 15672)}`,
+      protocol: (parsedConnectionUri.protocol === 'amqps') ? 'https' : 'http',
+    }
+
+    debug('Setting up AmqpStats with options: %o', ampqStatsOptions)
+
+    // Set up access to AmqpStats.
+    RabbitMQ.amqpStats = new AmqpStats(ampqStatsOptions)
+  }
 
-  // Set up access to AmqpStats.
-  RabbitMQ.amqpStats = new AmqpStats(ampqStatsOptions)
+  configureRabbit()
+    .then(() => configureAmqpStats())
+    .then(() => startSubscriptions())
 }