How to disable “Cannot Render Console from…” on Rails

Question

I\'m using Ubuntu/vagrant as my development environment. I\'m getting these messages on rails console:

Started GET \"/assets/home-fcec5b5a277ac7c20cc9f45a209         


        

Answer 1

Hardcoding an IP into a configuration file isn't good. What about other devs? What if the ip changes?

Docker-related config should not leak into the rails app whenever possible. That's why you should use env vars in the config/environments/development.rb file:

class Application < Rails::Application
  # Check if we use Docker to allow docker ip through web-console
  if ENV['DOCKERIZED'] == 'true'
    config.web_console.whitelisted_ips = ENV['DOCKER_HOST_IP']
  end
end

You should set correct env vars in a .env file, not tracked into version control.

In docker-compose.yml you can inject env vars from this file with env_file:

app:
  build: .
  ports:
   - "3000:3000"
  volumes:
    - .:/app
  links:
    - db
  environment:
    - DOCKERIZED=true
  env_file:
    - ".env"

Based on the feebdack received in comments, we can also build a solution without environment variables:

class Application < Rails::Application
  # Check if we use Docker to allow docker ip through web-console
  if File.file?('/.dockerenv') == true
    host_ip = `/sbin/ip route|awk '/default/ { print $3 }'`.strip
    config.web_console.whitelisted_ips << host_ip
  end
end

I'll leave the solutions with env var for learning purposes.