AWS Lambda Custom Runtime: Ruby 3.2 Support

Important: These docs are for the outdated Jets 5 versions and below. For the latest Jets docs: docs.rubyonjets.com

Update 6/7/2023: AWS has released the official Ruby 3.2 Runtime, see the AWS Blog Post. These docs are kept around for posterity and may be removed in the future.

Also see Upgrade Docs for upgrading.

To test Ruby 3.2 before of the official AWS Lambda release of Ruby 3.2 support, a Custom Lambda Runtime can be used. This doc also serves as an example of how to configure your own Custom Runtime with Jets.

Configure

config/application.rb

Jets.application.configure do
  # ...
  config.function.runtime = "provided.al2"
  config.lambda.layers = [
    "arn:aws:lambda:us-west-2:536766270177:layer:ruby_3-2:1",
  ]
end

Notes:

  • Important: Only use the Custom Runtime Layer for testing. It may be removed at any time in the future.
  • Once AWS releases the Ruby 3.2 runtime officially, you should use that instead.
  • AWS seems close according to this GitHub Issues Thread: Ruby 3.x support #636.
  • This note may already be outdated, and AWS has already released 3.2 support.

Custom Runtime for Different Regions

The Custom Runtime Lambda Layer needs to be in your same region. Choose from one in the list:

arn:aws:lambda:ap-south-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:eu-north-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:eu-west-3:536766270177:layer:ruby_3-2:1
arn:aws:lambda:eu-west-2:536766270177:layer:ruby_3-2:1
arn:aws:lambda:eu-west-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ap-northeast-3:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ap-northeast-2:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ap-northeast-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ca-central-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:sa-east-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ap-southeast-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:ap-southeast-2:536766270177:layer:ruby_3-2:1
arn:aws:lambda:eu-central-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:us-east-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:us-east-2:536766270177:layer:ruby_3-2:1
arn:aws:lambda:us-west-1:536766270177:layer:ruby_3-2:1
arn:aws:lambda:us-west-2:536766270177:layer:ruby_3-2:1

Deploy

To deploy, you should switch to Ruby 3.2 before deploying. Jets packages up gems based on the current ruby version in your environment. Here’s an example of deployment.

rbenv local 3.2.2
jets deploy

What Happens When AWS Releases Ruby 3.2

When AWS releases the official Ruby 3.2 runtime, Jets v4 should support it as-is. You just have to remove the Custom Runtime layer config.lambda.layers configuration in config/application.rb and jets deploy again. That’ll swap out the Custom Runtime with the Official Runtime. That’s how it’s supposed to work 😄

In this section: