Documentation for: v1.0.4 v2.1.3
Web Console is a debugging tool for your Ruby on Rails applications.
Installation
Web Console is meant to work as a Rails plugin. To install it in your current
application, add the following to your Gemfile
.
group :development do
gem 'web-console', '~> 3.0'
end
After you save the Gemfile
changes, make sure to run bundle install
and
restart your server for the Web Console to kick in.
Runtime
CRuby
CRuby 2.2 and below is not supported.
Rubinius
Internal errors like ZeroDevisionError
aren't caught.
Usage
The web console allows you to create an interactive Ruby session in your browser. Those sessions are launched automatically in case on an error, but they 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.
<% console %>
Calling console
in a controller will result in a console in the context of
the controller action:
class PostsController < ApplicationController
def new
console
@post = Post.new
end
end
Only one console
invocation is allowed per request. If you happen to have
multiple ones, a WebConsole::DoubleRenderError
is raised.
Configuration
Web Console allows you to execute arbitrary code on the server, so you should be very careful, who you give access to.
config.web_console.whitelisted_ips
By default, only requests coming from IPv4 and IPv6 localhosts are allowed.
config.web_console.whitelisted_ips
lets you control which IP's have access to
the console.
You can whitelist single IP's or whole networks. Say you want to share your
console with 192.168.0.100
. You can do this:
class Application < Rails::Application
config.web_console.whitelisted_ips = '192.168.0.100'
end
If you want to whitelist the whole private network, you can do:
Rails.application.configure do
config.web_console.whitelisted_ips = '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, a messages like 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 wanna see this message anymore, set this option to false
:
Rails.application.configure do
config.web_console.whiny_requests = false
end
config.web_console.template_paths
If you wanna style the console yourself, you can place style.css
at a
directory pointed by config.web_console.template_paths
:
Rails.application.configure do
config.web_console.template_paths = 'app/views/web_console'
end
You may wanna 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 you wanna change the path for some reasons, you can specify it
by config.web_console.mount_point
:
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 that is no longer bundled with Web Console.
If you miss this feature, check out rvt.
Why 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 get 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 server requests only out of one process.
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 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
Rails.application.configure do
config.middleware.insert(0, Rack::Deflater)
end
web_console
?
Why I'm getting an undefined method Make sure you configuration lives in config/environments/development.rb
.
Credits
- Shoutout to Charlie Somerville for better_errors.
- Kudos to John Mair for debug_inspector.
- Thanks to Charles Oliver Nutter for all the JRuby feedback.
- Hugs and kisses to all of our contributors!