Ruby Cloud Functions samples

This directory contains the Ruby samples for Cloud Run Functions.

Cloud Run functions is a lightweight, event-based, asynchronous compute solution that allows you to create small, single-purpose functions that respond to Cloud events without the need to manage a server or a runtime environment.

There are two versions of Cloud Run functions:

• Cloud Run functions, formerly known as Cloud Functions (2nd gen), which deploys your function as services on Cloud Run, allowing you to trigger them using Eventarc and Pub/Sub. Cloud Run functions are created using gcloud functions or gcloud run. Samples for Cloud Run functions can be found in the functions/v2 folder.
• Cloud Run functions (1st gen), formerly known as Cloud Functions (1st gen), the original version of functions with limited event triggers and configurability. Cloud Run functions (1st gen) are created using gcloud functions --no-gen2. Samples for Cloud Run functions (1st generation) can be found in the current functions/ folder.

Samples are organized one region tag (i.e. one sample) per file, where the file paths (directories and file names) match the region tags. For example, the sample for region tag functions_helloworld_http is in helloworld/http.rb.

Tests are organized similarly, one test file per sample file in the test directory. The test for functions_helloworld_http is in test/helloworld/http_test.rb. Tests generally do not deploy to GCF itself, but use the testing facilities provided by the Ruby Functions Framework.

Running the tests

In the functions directory:

bundle install
bundle exec rake test

Rubocop is generally run on the entire repository at once. Move up to the base directory and:

bundle install
bundle exec rubocop

Deploying a sample to Cloud Functions

Each sample comes with an app.rb file and a Gemfile, suitable for deploying to Google Cloud Functions. If you have Cloud Functions active in your project, you can deploy each sample directly from its directory.

First, install the bundle. Cloud Functions requires a locked bundle in order to deploy (to encourage you to test against a locked bundle).

bundle install

Next, deploy using the gcloud command line:

gcloud functions deploy $YOUR_FUNCTION_NAME --project=$YOUR_PROJECT_ID \
  --runtime=ruby26 --trigger-http --entry-point=$FUNCTION_TARGET_NAME

For functions that use a different trigger, such as storage events, you will need to replace --trigger-http with the appropriate trigger type. For more details, see the reference documentation for gcloud functions deploy.

Adding a sample

To add a sample:

• Determine the region tag for the sample (i.e. the string identifying the sample in the cloudsite source). This should always be a string beginning with functions_; for example, functions_helloworld_http.
• Create two levels of directories matching the region tag. For tag functions_helloworld_http, create the directory helloworld/http/. For tag functions_tips_infinite_retries, the directory should be just two levels deep: tips/infinite_retries.
• In this directory, create a Gemfile and app.rb. Write the sample in these files. You can use existing samples as a model.
• Create a test for the sample in the parallel test directory. For tag functions_helloworld_http, the test file should be test/helloworld/http_test.rb. You can use existing tests as a model.
• Make sure the test passes, as well as Rubocop. See the section above on running the tests.