Refactor init_containers building logic in TemplateMixin

[shyoon-devops]

Pull Request Checklist

• Fixes Issue: Incorrect env Structure in initContainers Generated by Hera #1155
• Tests added
• Documentation/examples added
• Good commit messages and/or PR title

PR Description

When using Hera to generate an Argo Workflow, I encountered an issue with the env structure in initContainers. Specifically, the env variable references for secrets are not being properly constructed. Instead of the correct structure with valueFrom, the generated YAML output directly assigns secret_name and secret_key, which is not valid in Argo Workflows.

This issue occurs because Hera doesn't handle this internally within its template constructors. Instead, it uses the initContainers as they are provided here. To address this, I created the _build_init_containers method in the TemplateMixin class.

    def _build_init_containers(self) -> Optional[List[ModelUserContainer]]:
        """Builds the `init_containers` field and optionally returns a list of `UserContainer`."""
        if self.init_containers is None:
            return None

        return [i.build() if isinstance(i, UserContainer) else i for i in self.init_containers]

This method ensures that the init_containers field is correctly constructed, and if any of the containers are instances of UserContainer, they are properly built before being returned.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.4%. Comparing base (d553546) to head (49e3d57).
Report is 124 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1157     +/-   ##
=======================================
- Coverage   81.7%   81.4%   -0.3%     
=======================================
  Files         54      60      +6     
  Lines       4208    4722    +514     
  Branches     889    1001    +112     
=======================================
+ Hits        3439    3846    +407     
- Misses       574     646     +72     
- Partials     195     230     +35     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[elliotgunton]

Thank you! 🚀