☸️ Lint Helm Chart Changes

[jasonBirchall]

User Need

As a software engineer making changes to our Helm charts repository
I want to lint changes automatically
so that I can feel confident my change will not break Helm’s rendering engine

Functional Requirements (What):

• Configure an automated linting process (e.g., using helm lint) to run on every pull request before merge
• Provide clear feedback (error messages/logs) to the developer when lint checks fail

Non-Functional Requirements (How):

• The lint check should run quickly (e.g., under two minutes) so as not to delay development workflows
• The lint check process should be secure and not expose sensitive credentials or data
• Lint logs and reports should be easily accessible for debugging and auditing

Acceptance Criteria:

• Helm lint runs automatically on all pull requests involving Helm chart changes
• If linting fails, the pull request is blocked from merging, and the developer is notified of the failure reasons
• Clear instructions or links to documentation are provided to help developers resolve linting issues
• Successful lint checks allow the pull request to be merged

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Notes:

• We will use the official Helm documentation on linting as a basis for this process.
• This work is being conducted in the repository for govuk-helm-charts.

[jasonBirchall]

This already exists, but mustn't be working.

[kentsanggds]

This already appears to do some linting on the charts in govuk-helm-charts https://github.com/alphagov/govuk-helm-charts/blob/main/.github/workflows/ci.yml#L19-L25

[kentsanggds]

This was the PR that got through the checks but shouldn't have - alphagov/govuk-helm-charts#2964

[kentsanggds]

Using this branch to test whether the lint can pick up the issue - alphagov/govuk-helm-charts@main...fix-chart-linting

Also reading this stackoverflow thread - https://stackoverflow.com/questions/48665209/validating-helm-chart-content

Might be worth exploring helm chart unittests - https://github.com/quintush/helm-unittest

[kentsanggds]

PR up for review alphagov/govuk-helm-charts#2985