fix: prevent startup if unable to connect to Rabbit

lib/index.js

@@ -39,23 +39,26 @@ module.exports = function loopbackComponentMq(app, settings) {
   RabbitMQ.log = _.get(settings, 'options.log', console)
   RabbitMQ.log = typeof RabbitMQ.log === 'string' ? require(RabbitMQ.log) : RabbitMQ.log
 
+  // Handle the case where unable to connect to Rabbit.
   rabbit.on('unreachable', () => {
     RabbitMQ.log.error('Unable to connect to Rabbit')
-    throw new Error('Unable to connect to Rabbit')
+    process.exit(1)
   })
 
   // Graceful shutdown.
   process.on('SIGINT', () => {
     debug('Caught SIGINT - performing graceful shutdown...')
     rabbit.shutdown()
-    process.exit(0)
+    process.exit(1)
   })
 
   // Configure the rabbit topology.
   rabbit.configure(settings.topology)
     .then(() => debug('Rabbit topology configured'))
-    .catch(err => RabbitMQ.log.error(err))
-
+    .catch(err => {
+      RabbitMQ.log.error('Unable to configure Rabbit topology', err.cause)
+      process.exit(1)
+    })
 
   const connection = rabbit.configurations.default.connection
   const parsedConnectionUri = url.parse(connection.uri)