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Stackdriver Logging (docs) allows you to store, search, analyze, monitor, and alert on log data and events from Google Cloud Platform and Amazon Web Services (AWS). It supports ingestion of any custom log data from any source. Stackdriver Logging is a fully-managed service that performs at scale and can ingest application and system log data from thousands of VMs. Even better, you can analyze all that log data in real-time.

Quick Start

Install the gem directly:

$ gem install google-cloud-logging

Or install through Bundler:

  1. Add the google-cloud-logging gem to your Gemfile:
gem "google-cloud-logging"
  1. Use Bundler to install the gem:
$ bundle install

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

Logging using client library

You can directly read or write log entries through the client library:

require "google/cloud/logging"

logging =

# List all log entries
logging.entries.each do |e|
  puts "[#{e.timestamp}] #{e.log_name} #{e.payload.inspect}"

# List only entries from a single log
entries = logging.entries filter: "log:syslog"

# Write a log entry
entry = logging.entry
entry.payload = "Job started."
entry.log_name = "my_app_log"
entry.resource.type = "gae_app"
entry.resource.labels[:module_id] = "1"
entry.resource.labels[:version_id] = "20150925t173233"

logging.write_entries entry

Using Stackdriver Logging in frameworks

The google-cloud-logging library provides framework integration for popular Rack-based frameworks, such as Ruby on Rails and Sinatra, which sets the default Rack logger to an instance of the Stackdriver Logging logger.

With Ruby on Rails

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/logging/rails"

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

You'll be able to use Stackdriver logger through the standard Rails logger: "Hello World"
# Or just...
logger.warn "Hola Mundo"

With other Rack-based frameworks

Other Rack-based applications can use the Rack Middleware to replace the Rack logger with the Stackdriver Logging logger:

require "google/cloud/logging"
use Google::Cloud::Logging::Middleware

Once the Rack logger is set, some Rack-based frameworks, such as Ruby on Rails and Sinatra, automatically initialize the default application logger to use the Rack logger: "Hello World"
logger.warn "Hola Mundo"
logger.error "Bonjour Monde"

For other frameworks, consult the documentations on how to utilize the Rack logger.

Configuring the framework integration

You can customize the behavior of the Stackdriver Logging framework integration for Ruby. See the configuration guide for a list of possible configuration options.


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.

If you're using Ruby on Rails and the library's Rails integration feature, you can provide the authentication parameters through the Rails configuration interface:

# Add this to 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"
  # Stackdriver Logging specific parameters
  config.google_cloud.logging.project_id = "your-project-id"
  config.google_cloud.logging.keyfile    = "/path/to/key.json"

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

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

See the Authentication Guide. for more ways to authenticate the client library.

Enabling Logging

To enable logging for this library, set the logger for the underlying gRPC library. The logger that you set may be a Ruby stdlib Logger as shown below, or a Google::Cloud::Logging::Logger that will write logs to Stackdriver Logging. See grpc/logconfig.rb and the gRPC spec_helper.rb for additional information.

Configuring a Ruby stdlib logger:

require "logger"

module MyLogger
  LOGGER = $stderr, level: Logger::WARN
  def logger

# Define a gRPC module-level logger method before grpc/logconfig.rb loads.
module GRPC
  extend MyLogger

Supported Ruby Versions

This library is supported on Ruby 2.3+.

Google provides official support for Ruby versions that are actively supported by Ruby Core—that is, Ruby versions that are either in normal maintenance or in security maintenance, and not end of life. Currently, this means Ruby 2.3 and later. Older versions of Ruby may still work, but are unsupported and not recommended. See for details about the Ruby support schedule.


This library follows Semantic Versioning.


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.

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