son-gtksrv prevent crash if rabbitmq is not available when boot

[felipevicens]

If rabbitmq is not available then the container crashs:

Puma starting in single mode...
* Version 3.11.0 (ruby 2.4.3-p205), codename: Love Song
* Min threads: 0, max threads: 16
* Environment: development
W, [2018-03-04T12:03:39.634952 #1]  WARN -- #<Bunny::Session:0x557e3a0ea200 guest@broker:5672, vhost=/, addresses=[broker:5672]>: Could not establish TCP connection to broker:5672: getaddrinfo: No address associated with hostname
! Unable to load application: Bunny::TCPConnectionFailedForAllHosts: Could not establish TCP connection to any of the configured hosts
bundler: failed to load command: puma (/usr/local/bundle/bin/puma)
Bunny::TCPConnectionFailedForAllHosts: Could not establish TCP connection to any of the configured hosts
  /usr/local/bundle/gems/bunny-2.8.0/lib/bunny/session.rb:329:in `rescue in start'
  /usr/local/bundle/gems/bunny-2.8.0/lib/bunny/session.rb:297:in `start'
  /app/models/mq_server.rb:42:in `initialize'
  /app/gtk_srv.rb:99:in `new'
  /app/gtk_srv.rb:99:in `<class:GtkSrv>'
  /app/gtk_srv.rb:50:in `<top (required)>'
  config.ru:29:in `require'
  config.ru:29:in `block in <main>'
  /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:55:in `instance_eval'
  /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:55:in `initialize'
  config.ru:in `new'
  config.ru:in `<main>'
  /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:49:in `eval'
  /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:49:in `new_from_string'
  /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:40:in `parse_file'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/configuration.rb:318:in `load_rackup'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/configuration.rb:243:in `app'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/runner.rb:138:in `load_and_bind'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/single.rb:87:in `run'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/launcher.rb:183:in `run'
  /usr/local/bundle/gems/puma-3.11.0/lib/puma/cli.rb:77:in `run'
  /usr/local/bundle/gems/puma-3.11.0/bin/puma:10:in `<top (required)>'
  /usr/local/bundle/bin/puma:21:in `load'
  /usr/local/bundle/bin/puma:21:in `<top (required)>'

[jbonnet]

Hmm...
Shall we add some 'waiting' cycles when deploying, like when we deploy User Management, or do you see another approach?

[felipevicens]

Maybe some error handling and heartbeat as described here:

http://rubybunny.info/articles/error_handling.html

and here:

http://rubybunny.info/articles/connecting.html