Configuration

There are a few things you can configure in the Debugbar. The configuration happens in two places:

• in config/initializers/debugbar.rb for the general gem configuration
• in a script tag in your page for some specific configuration

Ensure ruby configuration is only loaded in development

Because the debugbar shouldn’t be loaded in other environments, you should ensure the configuration is only loaded in development. One solution is to put the configuration directly in config/environments/development.rb, underneath the Rails.application.configure do block.

Rails.application.configure do
  # ...
end

Debugbar.configure do |config|
  config.enabled = false
end

If you prefer to have a dedicated initializer, you can wrap the configuration in a if Rails.env.development? block or make sure the code is only executed if Debugbar is defined.

return unless defined? Debugbar

Debugbar.configure do |config|
  config.enabled = true
end

Enable/disable the Debugbar

You can enable/disable the Debugbar by setting the enabled option in the initializer:

Debugbar.configure do |config|
  config.enabled = false # or ENV['DEBUGBAR_ENABLED'] == 'true' for example
end

Ignoring requests

Once the debugbar is enabled, every request will be monitored and the debugbar will be displayed. You can ignore some requests by setting the ignore_request option in the initializer. This is typically useful to ignore some requests that are not relevant to you.

By default, the debugbar will ignore all requests starting with /assets or /_debugbar.

Debugbar.configure do |config|
  # Ignore all requests starting with /admin
  config.ignore_request = -> (env) { env['PATH_INFO'].start_with? '/admin' }

  # Only log request to the API
  config.ignore_request = -> (env) { not env['PATH_INFO'].start_with? '/api/v1' }

  # Ignore requests to admin, assets and debugbar
  config.ignore_request = -> (env) do
    [Debugbar.config.prefix, "/assets", "/admin"].any? do |pfx|
      env['PATH_INFO'].start_with? pfx
    end
  end
end

Using a different buffer

Whenever a request is made to the backend, the debugbar will store the data in a buffer. By default, the buffer is an in-memory buffer. You can use a different buffer by setting the buffer_adapter option in the initializer. So far, there is only a memory buffer and a null buffer.

A persisted buffer is coming to support Puma in cluster mode. Custom adapters will also be available.

Debugbar.configure do |config|
  config.buffer_adapter = :memory  # Use a memory buffer
  config.buffer_adapter = :null    # Use a null buffer
end

Enable/disable a feature

This is shown in the [features] section, but generally, you can enable/disable a feature in the initializer. By default, all features are enabled if the underlying module is available. For example, Active Record is enabled if the ActiveRecord module is available.

Debugbar.configure do |config|
  config.active_record = false
  config.cache = true
end

Changing URL and port

By default, the frontend will connect to localhost:3000. If you use another port or a domain, you need to pass the URL to the frontend. If you use http polling, checkout this page.

With the ERB helper, you can pass a hash to override any configuration defined here.

<%= debugbar_body  cable: {url: "ws://something.test:3030"} %>

If you don’t use the helper, you must define a _debugbarConfigOptions object.

window._debugbarConfigOptions = {
    cable: {
      url: 'ws://something.test:3030'
    },
}

Using SSL

The configuration requires you to pass the entire URL, so if you use SSL locally, you can use wss instead of ws.

<%= debugbar_body  cable: {url: "wss://localhost:3000"} %>

window._debugbarConfigOptions = {
    cable: {
      url: 'wss://localhost:3000'
    },
}

Using another prefix

All endpoints added by the debugbar are prefixed with /_debugbar. It’s unlikely that you’ll need to change the prefix, but if you do, you can set the prefix option in the initializer.

If you change it, it also needs to be changed in the frontend configuration

Debugbar.configure do |config|
  config.prefix = '/custom-prefix'
end

<%= debugbar_body  prefix: "/custom-prefix" %>

Debugbar appearance

Custom default height

If you’re working on a fairly big screen, you can configure the default height of the debugbar when it opens. Pass a value in pixel.

<%= debugbar_body height: 800 %>

Minimized by default

If you prefer, the debugbar can load minimized by default, so you just see the little ruby logo at the bottom left of the screen.

<%= debugbar_body minimized: true %>

Frontend configuration without the helper

If you are not using the ERB view helper to render the debugbar (typically because you have an SPA and the shell isn’t rendered by Rails), there is some configuration that might be missing.

<script type="text/javascript" data-turbo-permanent>
  window._debugbarConfigOptions = {
    activeRecord: {
      adapter: "pgsql",
    },
  }
</script>