Deploy ruby api google cloud

Question

I'm pretty new to Google cloud and I have this issue when I try to deploy my ruby api to google cloud, here goes what I have done:

I have uploaded my ruby api to github (it works fine on localhost), here >> https://github.com/guisantogui/it

I have been trough hello world google tutorial >> https://cloud.google.com/ruby/getting-started/hello-world

and it worked as expected, but when I upload my own application I got this http 502 bad gateway message, here goes the logs:

2017-10-30 23:48:53 default[20171030t213633]  => Booting Puma
2017-10-30 23:48:53 default[20171030t213633]  => Rails 5.1.4 application starting in production 
2017-10-30 23:48:53 default[20171030t213633]  => Run `rails server -h` for more startup options
2017-10-30 23:48:53 default[20171030t213633]  Puma starting in single mode... 
2017-10-30 23:48:53 default[20171030t213633]  * Version 3.10.0 (ruby 2.4.1-p111), codename: Russell's Teapot
2017-10-30 23:48:53 default[20171030t213633]  * Min threads: 5, max threads: 5
2017-10-30 23:48:53 default[20171030t213633]  * Environment: production
2017-10-30 23:48:53 default[20171030t213633]  * Listening on tcp://0.0.0.0:3000 
2017-10-30 23:48:53 default[20171030t213633] Use Ctrl-C to stop 
2017-10-30 23:58:01 default[20171030t213633]  "GET /" 502 
2017-10-30 23:58:02 default[20171030t213633]  "GET /favicon.ico" 502 
2017-10-30 23:58:06 default[20171030t213633]  "GET /" 502 
2017-10-30 23:58:06 default[20171030t213633]  "GET /favicon.ico" 502 
2017-11-01 10:54:50 default[20171030t213633]  "GET /" 502 
2017-11-01 10:54:50 default[20171030t213633]  "GET /favicon.ico" 502 
2017-11-01 10:55:02 default[20171030t213633]  "GET /favicon.ico" 502 
2017-11-01 10:55:02 default[20171030t213633]  "GET /tatoo_artis/list" 502

And finally and i think more important the app.yaml file:

entrypoint: bundle exec rails server Puma -p 3000
env: flex
runtime: ruby

Thanks in advance, i got no idea what is the problem and how to fix it!

Answer 1

The Google Cloud example https://cloud.google.com/ruby/getting-started/hello-world uses Sinatra, not Rails. If you check https://github.com/GoogleCloudPlatform/ruby-docs-samples/tree/master/appengine/hello_world in the app.yaml file it just has:

# [START app_yaml]
runtime: ruby
env: flex
entrypoint: bundle exec ruby app.rb
# [END app_yaml]

And app.rb is just a simple sinatra app.

# [START app]
require "sinatra"
get "/" do
  "Hello world!"
end
# [END app]

Rails configuration is a little bit more complex. First of all it seems that GCP App Engine doesn't support Puma (please correct me if I am wrong), but rackup, and you need to set some environment variables like the SECRET_KEY (use bundle exec rails secret ), so your app.yaml file should be:

# [START app_yaml]
runtime: ruby
env: flex
entrypoint: bundle exec rackup --port $PORT
env_variables:
  SECRET_KEY_BASE: [SECRET_KEY]
# [END app_yaml]

Remember you also need to run:

RAILS_ENV=production bundle exec rails assets:precompile

before running

gcloud app deploy

to precompile your assets.

What you are looking for is in this guide: https://cloud.google.com/ruby/rails/appengine , skip the initial steps (since you already have the app) and go straight to: "Deploy the app to the App Engine flexible environment"

Sources: Google guide: https://cloud.google.com/ruby/rails/appengine

Code: https://github.com/GoogleCloudPlatform/ruby-docs-samples/tree/master/appengine/rails-hello_world

EDIT: I see you have some GET requests in your logs, so maybe Puma is supported. Try to just set up the SECRET_KEY and precompile your assets before deploy.