Stackdriver Debugger lets you inspect the state of a running application at any code location in real time, without stopping or slowing down the application, and without modifying the code to add logging statements. You can use Stackdriver Debugger with any deployment of your application, including test, development, and production. The Ruby debugger adds minimal request latency, typically less than 50ms, and only when the application state is captured. In most cases, this is not noticeable by users.

• google-cloud-debugger documentation
• google-cloud-debugger on RubyGems
• Stackdriver Debugger documentation

Install the gem directly:

$ gem install google-cloud-debugger

Or install through Bundler:

1. Add the google-cloud-debugger gem to your Gemfile:

gem "google-cloud-debugger"

2. Use Bundler to install the gem:

$ bundle install

Alternatively, check out the stackdriver gem that includes the google-cloud-debugger gem.

The Stackdriver Debugger agent needs the Stackdriver Debugger API to be enabled on your Google Cloud project. Make sure it's enabled if not already.

The Stackdriver Debugger library provides a Debugger agent that helps instrument breakpoints in your running applications. The library also comes with a Railtie and a Rack Middleware to help control the Debugger agent in popular Rack based frameworks, such as Ruby on Rails and Sinatra.

You can load the Railtie that comes with the library into your Ruby on Rails application by explicitly requiring it during the application startup:

# In config/application.rb
require "google/cloud/debugger/rails"

If you're using the stackdriver gem, it automatically loads the Railtie into your application when it starts.

Other Rack-based frameworks, such as Sinatra, can use the Rack Middleware provided by the library:

require "google/cloud/debugger"
use Google::Cloud::Debugger::Middleware

Non-rack-based applications can start the agent explicitly at the entry point of your application:

require "google/cloud/debugger"
Google::Cloud::Debugger.new.start

You can customize the behavior of the Stackdriver Debugger agent. See the agent configuration for a list of possible configuration options.

The Stackdriver Debugger agent should work without you manually providing authentication credentials for instances running on Google Cloud Platform, as long as the Stackdriver Debugger API access scope is enabled on that instance.

On Google App Engine, the Stackdriver Debugger API access scope is enabled by default, and the Stackdriver Debugger agent can be used without providing credentials or a project ID.

On Google Container Engine, you must explicitly add the cloud_debugger OAuth scope when creating the cluster:

$ gcloud container clusters create example-cluster-name --scopes https://www.googleapis.com/auth/cloud_debugger

You can also do this through the Google Cloud Platform Console. Select Enabled in the Cloud Platform section of Create a container cluster.

To use Stackdriver Debugger, Compute Engine VM instances should have one of the following access scopes. These are only relevant when you use Compute Engine's default service account:

• https://www.googleapis.com/auth/cloud-platform
• https://www.googleapis.com/auth/cloud_debugger

The cloud-platform access scope can be supplied when creating a new instance through the Google Cloud Platform Console. Select Allow full access to all Cloud APIs in the Identity and API access section of Create an instance.

The cloud_debugger access scope must be supplied manually using the SDK's gcloud compute instances create command or the gcloud compute instances set-service-account command.

To run the Stackdriver Debugger agent outside of Google Cloud Platform, you must supply your GCP project ID and appropriate service account credentials directly to the Stackdriver Debugger agent. This applies to running the agent on your own workstation, on your datacenter's computers, or on the VM instances of another cloud provider. See the Authentication section for instructions on how to do so.

This library uses Service Account credentials to connect to Google Cloud services. When running on Compute Engine the credentials will be discovered automatically. When running on other environments the Service Account credentials can be specified by providing in several ways.

The best way to provide authentication information if you're using Ruby on Rails is through the Rails configuration interface:

# in config/environments/*.rb
Rails.application.configure do |config|
  # Shared parameters
  config.google_cloud.project_id = "your-project-id"
  config.google_cloud.keyfile = "/path/to/key.json"
  # Or Stackdriver Debugger agent specific parameters
  config.google_cloud.debugger.project_id = "your-project-id"
  config.google_cloud.debugger.keyfile = "/path/to/key.json"
end

Other Rack-based applications that are loading the Rack Middleware directly can use the configration interface:

require "google/cloud/debugger"
Google::Cloud.configure do |config|
  # Shared parameters
  config.project_id = "your-project-id"
  config.keyfile = "/path/to/key.json"
  # Or Stackdriver Debugger agent specific parameters
  config.debugger.project_id = "your-project-id"
  config.debugger.keyfile = "/path/to/key.json"
end

Or provide the parameters to the Stackdriver Debugger agent when it starts:

require "google/cloud/debugger"
Google::Cloud::Debugger.new(project_id: "your-project-id",
                            credentials: "/path/to/key.json").start

This library also supports the other authentication methods provided by the google-cloud-ruby suite. Instructions and configuration options are covered in the Authentication Guide.

This library is supported on Ruby 2.2+.

This library follows Semantic Versioning.

It is currently in major version zero (0.y.z), which means that anything may change at any time and the public API should not be considered stable.

Contributions to this library are always welcome and highly encouraged.

See the Contributing Guide for more information on how to get started.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. See Code of Conduct for more information.

This library is licensed under Apache 2.0. Full license text is available in LICENSE.

Please report bugs at the project on Github. Don't hesitate to ask questions about the client or APIs on StackOverflow.