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

The 10.0.2.2 network space in the Web Console config. 

class Application < Rails::Application
  config.web_console.whitelisted_ips = '10.0.2.2'
end

This  config/environments/development.rb rather than config/application.rb it  only applied development environment.

whitelist single IP’s or whole networks 192.168.0.100:

class Application < Rails::Application
  config.web_console.whitelisted_ips = '192.168.0.100'
end

private network:

class Application < Rails::Application
  config.web_console.whitelisted_ips = '192.168.0.0/16'
end

Option to false:

class Application < Rails::Application
config.web_console.whiny_requests = false
end

A development purposes might prefer to place it under config/environments/development.rb above of config/application.rb.

config/environments/development.rb:

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

Docker-compose.yml  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"

Auto discovery within your config/development.rb

config.web_console.whitelisted_ips = Socket.ip_address_list.reduce([]) do |res, addrinfo|
    addrinfo.ipv4? ? res << IPAddr.new(addrinfo.ip_address).mask(24) : res
end

Of course might need to add

require 'socket'
require 'ipaddr'

Within your file.