Migrate to HEAT HOT language

Migrate to HEAT HOT language

https://blueprints.launchpad.net/sahara/+spec/heat-hot

This blueprint suggests to rewrite cluster template for Heat from JSON to HOT language.

Problem description

Heat supports two different template languages: YAML-based HOT templates and JSON-based CFN templates (no documentation about it, only a number of examples).

HOT is the de-facto main markup language for Heat. Template Guide recommends to use HOT and contains examples for HOT only.

CFN templates are supported mostly for compatibility with AWS CloudFormation.

Sahara historically uses CFN templates. Given that Sahara is an integrated OpenStack project it would be nice to switch to HOT.

Proposed change

There is no urgent need in switching to HOT. But it would be nice to be compliant with current tendencies in community.

This spec suggests to use HOT template language for sahara heat templates.

This will require changes mostly in .heat resources. Code that generate template parts on the fly should be changed too.

Having templates written on HOT will simplify implementation of new heat-related features like template decomposition.

Alternatives

Do not change anything.

Data model impact

None.

REST API impact

None.

Other end user impact

None.

Deployer impact

None.

Developer impact

None.

Sahara-image-elements impact

None.

Sahara-dashboard / Horizon impact

None.

Implementation

Assignee(s)

Primary assignee:
alazarev (Andrew Lazarev)
Other contributors:
None

Work Items

  • Change all .heat files used by Sahara
  • Update code that generates parts of template
  • Update unit tests
  • Make sure that sahara with heat engine still works in all supported configurations

Dependencies

None

Testing

Mostly manually. CI should also cover heat changes.

Documentation Impact

None.

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.

sahara-specs 0.0.1.dev337