Proposal: Templates from gems

[mipearson]

(unlike the other proposals, this one is for stack_master 1, not 2)

I want to be able to ship CFN templates (.yml) as part of a private gem for others to use.

The workflow would be:

1. Add to Gemfile, lock to patch version
2. Reference template(s) in gem in stack_master.yml as normal
3. Update incrementally & carefully if desired

stack_master.yml would look like:

stacks:
  us-east-1:
    my-vpc:
      gem-template: mygem:vpc.yml

mygem would be discovered and an error displayed if the gem is not found or the template does not exist. mygem would only consist of a mostly-empty mygem.gemspec and a templates directory.

Optionally other stack_master compiled formats (eg sparkleformation, cfndsl) could be supported.

This would also allow people wishing to modify / contribute back to the templates in the gem to vendor it locally using the existing Bundler mechanisms for working on code locally

[rbayerl]

I would rather see it as mygem:vpc.yml rather than taking over the idea of a local path. Other than that no opinion. Another option would be something like:

stacks:
  us-east-1:
    my-vpc:
      gem-template:
        mygem: vpc.yml

[mipearson]

@rbayerl yeah, mygem:vpc.yml is better. Ta. Editing original issue.

[patrobinson]

Are Rubygems the right packaging format? Should we support just plain Git instead (with tags support)? Or perhaps tarballs fetched via HTTP (and possibly S3 for private access)?

[viraptor]

If there's still a need for distributed yml templates, it may be worth checking if sparkle_pack support can be extended to do the same. Gem-distributed rb files are already possible: https://github.com/envato/kms_sparkle_pack