An open source framework for writing lightweight, portable Ruby functions that run in a serverless environment. Functions written to this Framework will run in many different environments, including:

• Google Cloud Functions
• Google Cloud Run
• Any other Knative-based environment
• Your local development machine

The framework allows you to go from:

FunctionsFramework.http("hello") do |request|
  "Hello, world!\n"
end

To:

curl http://my-url
# Output: Hello, world!

Running on a fully-managed or self-managed serverless environment, without requiring an HTTP server or complicated request handling logic.

• Define named functions using normal Ruby constructs.
• Invoke functions in response to requests.
• Automatically unmarshal events conforming to the CloudEvents spec.
• Automatically convert most legacy events from Google Cloud services such as Cloud Pub/Sub and Cloud Storage, to CloudEvents.
• Spin up a local development server for quick testing.
• Integrate with standard Ruby libraries such as Rack and Minitest.
• Portable between serverless platforms.
• Supports all non-end-of-life versions of Ruby.

This library is supported on Ruby 2.6+.

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. Older versions of Ruby may still work, but are unsupported and not recommended. See https://www.ruby-lang.org/en/downloads/branches/ for details about the Ruby support schedule.

Here is how to run a Hello World function on your local machine.

Create a Gemfile listing the Functions Framework as a dependency:

# Gemfile
source "https://rubygems.org"
gem "functions_framework", "~> 1.0"

Create a file called app.rb and include the following code. This defines a simple function called "hello".

# app.rb
require "functions_framework"

FunctionsFramework.http("hello") do |request|
  "Hello, world!\n"
end

Install the bundle, and start the framework. This spins up a local web server running your "hello" function:

bundle install
# ...installs the functions_framework gem and other dependencies
bundle exec functions-framework-ruby --target hello
# ...starts the web server in the foreground

In a separate shell, you can send requests to this function using curl:

curl http://localhost:8080
# Output: Hello, world!

Stop the server with CTRL+C.

These guides provide additional getting-started information.

• Writing Functions : How to write functions that respond to HTTP requests, industry-standard CloudEvents, as well as events sent from Google Cloud services such as Pub/Sub and Storage.
• Testing Functions : How to use the testing features of the Functions Framework to write local unit tests for your functions using standard Ruby testing frameworks such as Minitest and RSpec.
• Running a Functions Server : How to use the functions-framework-ruby executable to run a local functions server.
• Deploying Functions : How to deploy functions to Google Cloud Functions or Google Cloud Run.

The library reference documentation can be found at: https://googlecloudplatform.github.io/functions-framework-ruby

Additional examples are available in the examples directory: https://github.com/GoogleCloudPlatform/functions-framework-ruby/blob/master/examples/

The source for the Ruby Functions Framework is available on GitHub at https://github.com/GoogleCloudPlatform/functions-framework-ruby. For more information on the Functions Framework contract implemented by this framework, as well as links to Functions Frameworks for other languages, see https://github.com/GoogleCloudPlatform/functions-framework.

The Functions Framework is open source under the Apache 2.0 license. Contributions are welcome. Please see the contributing guide at https://github.com/GoogleCloudPlatform/functions-framework-ruby/blob/master/.github/CONTRIBUTING.md.

Report issues at https://github.com/GoogleCloudPlatform/functions-framework-ruby/issues.