Jets app deploys that have a Job error out with "YAML aliases are not allowed in CloudFormation templates"

[sam0x17]

Checklist

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• Reproducibility: Are you reporting a bug others will be able to reproduce and not asking a question. If you're unsure or want to ask a question, do so on https://community.rubyonjets.com
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My Environment

Software	Version
Operating System	Ubuntu 20.04
Jets	3.0.9
Ruby	2.7.2

---

Expected Behaviour

Deploying a jets app that includes an active job with a cron trigger succeeds

Current Behavior

Deploying a jets app that that includes an active job with a cron trigger fails with this error during deploy:

YAML aliases are not allowed in CloudFormation templates

Step-by-step reproduction instructions

Try deploying an app with an active job that has a cron trigger string

Code Sample

Example job:

class MessengerJob < ApplicationJob
  class_timeout 10.minutes
  environment(DB_POOL: 32)

  cron '0/1 * * * ? *' # at the start of every minute
  def process_messages
    # do work here
  end
end

Solution Suggestion

We tried tweaking a bunch of things and still get the same error, so I suspect this is a general issue not related to our specific cron string, but I could be wrong

[tongueroo]

Bummer. What's going on is the

  class_timeout 10.minutes

Creates the YAML aliases error.

When jets builds the project and the cloudformation templates it calls YAML dump. With 10.minutes is a ActiveSupport::Duration class. The YAML dump serializes this info into the yaml.

$ jets build
$ grep -A 3 Timeout /tmp/jets/demo/templates/demo-dev-app-messenger_job.yml
      Timeout: !ruby/object:ActiveSupport::Duration
        value: 600
        parts:
          :minutes: 10

The serialization creates a !ruby/object:ActiveSupport::Duration, which CloudFormation thinks is a YAML alias and hence the error.

Instead you'll can do this:

  class_timeout 10.minutes.to_i

The produces:

$ jets build
$ grep Timeout /tmp/jets/demo/templates/demo-dev-app-messenger_job.yml
      Timeout: 600

So try using class_timeout 10.minutes.to_i, that should deploy successfully.

Also, looked into possibly doing a .to_i conversion on ActiveSupport::Duration values 🧐 But unsure if it's worth it at the moment. Closing for now. Hope that helps.