Add workflow to auto-bump koku image in cost-onprem-chart

[ELK4N4]

Summary

• Adds a new GitHub Actions workflow (bump-cost-chart.yml) that automatically bumps the koku image tag in the insights-onprem/cost-onprem-chart repo whenever a PR with the flightpath-pr label is merged to main.
• The workflow creates a PR in cost-onprem-chart that updates values.yaml with the merge commit SHA and bumps the chart RC version via scripts/bump-version.sh --rc.
• Uses a GitHub App (COST_CHART_APP_ID / COST_CHART_APP_PRIVATE_KEY secrets) for cross-repo authentication, avoiding any dependency on personal tokens.

How it works

1. Triggers on pull_request closed (merged) to main with flightpath-pr label
2. Generates a short SHA tag from the merge commit
3. Obtains a GitHub App installation token scoped to insights-onprem/cost-onprem-chart
4. Checks out cost-onprem-chart, updates the koku image tag in values.yaml, bumps the chart version
5. Pushes a branch and opens a PR in cost-onprem-chart with links back to the source koku PR/commit

Prerequisites

Before this workflow can run, the following must be set up:

1. A GitHub App in the insights-onprem org with Contents (R/W) and Pull requests (R/W) permissions
2. The app installed on the cost-onprem-chart repo
3. Two repository secrets in project-koku/koku:
   • COST_CHART_APP_ID
   • COST_CHART_APP_PRIVATE_KEY
4. The flightpath-pr label must exist in this repo

Test plan

• Verify workflow YAML is valid (passes Actions lint)
• Set up GitHub App and secrets in a test environment
• Merge a test PR with flightpath-pr label and confirm the workflow creates a PR in cost-onprem-chart with correct image tag and bumped chart version

Made with Cursor

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.3%. Comparing base (87ad6a1) to head (a875c95).

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #6039     +/-   ##
=======================================
- Coverage   94.3%   94.3%   -0.0%     
=======================================
  Files        361     361             
  Lines      31805   31805             
  Branches    3484    3484             
=======================================
- Hits       30007   30003      -4     
  Misses      1170    1170             
- Partials     628     632      +4     

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