Current version: 4.2.1 | Documentation for: v1.0.4 v2.2.1 v3.7.0

# Web Console [![CI](https://github.com/rails/web-console/actions/workflows/ci.yml/badge.svg)](https://github.com/rails/web-console/actions/workflows/ci.yml) _Web Console_ is a debugging tool for your Ruby on Rails applications. - [Installation](#installation) - [Configuration](#configuration) - [Usage](#usage) - [FAQ](#faq) - [Credits](#credits) ## Installation Add the following to your `Gemfile`: ```ruby group :development do gem 'web-console' end ``` ## Usage The web console allows you to create an interactive Ruby session in your browser. Those sessions are launched automatically in case of an error and can also be launched manually in any page. For example, calling `console` in a view will display a console in the current page in the context of the view binding. ```html <% console %> ``` Calling `console` in a controller will result in a console in the context of the controller action: ```ruby class PostsController < ApplicationController def new console @post = Post.new end end ``` The method is defined in `Kernel` and you can invoke it any application code. Only one `console` invocation per request is allowed. If you happen to have multiple ones, `WebConsole::DoubleRenderError` will be raised. ## Configuration _Web Console_ allows you to execute arbitrary code on the server. Therefore, be very careful who you give access to. ### config.web_console.permissions By default, only requests coming from IPv4 and IPv6 localhosts are allowed. `config.web_console.permissions` lets you control which IP's have access to the console. You can allow single IP's or whole networks. Say you want to share your console with `192.168.0.100`: ```ruby class Application < Rails::Application config.web_console.permissions = '192.168.0.100' end ``` If you want to allow the whole private network: ```ruby Rails.application.configure do config.web_console.permissions = '192.168.0.0/16' end ``` Take a note that IPv4 and IPv6 localhosts are always allowed. This wasn't the case in 2.0. ### config.web_console.whiny_requests When a console cannot be shown for a given IP address or content type, messages such as the following is printed in the server logs: > Cannot render console from 192.168.1.133! Allowed networks: > 127.0.0.0/127.255.255.255, ::1 If you don't want to see this message anymore, set this option to `false`: ```ruby Rails.application.configure do config.web_console.whiny_requests = false end ``` ### config.web_console.template_paths If you want to style the console yourself, then you can place `style.css` at a directory pointed by `config.web_console.template_paths`: ```ruby Rails.application.configure do config.web_console.template_paths = 'app/views/web_console' end ``` You may want to check the [templates] folder at the source tree for the files you may override. ### config.web_console.mount_point Usually the middleware of _Web Console_ is mounted at `/__web_console`. If there is a need to change the path, then you can specify it by `config.web_console.mount_point`: ```ruby Rails.application.configure do config.web_console.mount_point = '/path/to/web_console' end ``` ## FAQ ### Where did /console go? The remote terminal emulator was extracted in its own gem which is no longer bundled with _Web Console_. If you miss this feature, check out [rvt]. ### Why do I constantly get unavailable session errors? All of _Web Console_ sessions are stored in memory. If you happen to run on a multi-process server (like Unicorn), you may encounter unavailable session errors while the server is still running. This is because a request may hit a different worker (process) that doesn't have the desired session in memory. To avoid that, if you use such servers in development, configure them so they serve requests only out of one process. #### Passenger Enable sticky sessions for [Passenger on Nginx] or [Passenger on Apache] to prevent unavailable session errors. ### How to inspect local and instance variables? The interactive console executes Ruby code. Invoking `instance_variables` and `local_variables` will give you what you want. ### Why does the console only appear on error pages but not when I call it? This can be happening if you are using `Rack::Deflater`. Be sure that `WebConsole::Middleware` is used after `Rack::Deflater`. The easiest way to do this is to insert `Rack::Deflater` as early as possible ```ruby Rails.application.configure do config.middleware.insert(0, Rack::Deflater) end ``` ### Why am I getting an undefined method `web_console`? Make sure your configuration lives in `config/environments/development.rb`. ## Credits * Shoutout to [Hailey Somerville] for [better_errors]. * Kudos to [John Mair] for [binding_of_caller] and [debug_inspector]. * Thanks to [Charles Oliver Nutter] for all the _JRuby_ feedback. * Hugs and kisses to all of our [contributors]! [better_errors]: https://github.com/BetterErrors/better_errors [debug_inspector]: https://github.com/banister/debug_inspector [binding_of_caller]: https://github.com/banister/binding_of_caller [Hailey Somerville]: https://github.com/haileys [John Mair]: https://github.com/banister [Charles Oliver Nutter]: https://github.com/headius [templates]: https://github.com/rails/web-console/tree/main/lib/web_console/templates [rvt]: https://github.com/gsamokovarov/rvt [contributors]: https://github.com/rails/web-console/graphs/contributors [Passenger on Nginx]: https://www.phusionpassenger.com/library/config/nginx/reference/#passengerstickysessions [Passenger on Apache]: https://www.phusionpassenger.com/library/config/apache/reference/#passengerstickysessions