Using PrometheusRule Linter in Github Action pipeline

Introduction

This is a guide of how to use the prometheus operator linter to check PrometheusRules YAML files for syntax errors within a CI/CD pipeline.

Github Repository: cloud-platform-po-linter

Using Linter in Github Actions

This Linter should be ran on pull request on new PrometheusRule yaml if their is a error the binary will return with a error detailing the incorrect syntax.

Required to run linter:

• GITHUB_OAUTH_TOKEN: This should be the repository key to allow binary to run on the pull request
• REPO_DIRECTORY: This is the directory where the yaml file will be stored

Required for commenting results to Pull Request:

• steps.po-linter.outputs.po-linter: This is needed if you want to print error.

Example

name: Prometheus Operator Linter

on:
  pull_request:
    paths:
    - <DIRECTORY>/<FILE>
  workflow_dispatch:

jobs:
  po-lint:
    runs-on: ${{ matrix.os }}

    strategy:
      matrix:
        os: [ubuntu-latest]

    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Run po-linter
        uses: docker://ministryofjustice/cloud-platform-po-linter:latest
        continue-on-error: true
        id: po-linter
        env:
          GITHUB_OAUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          REPO_DIRECTORY: <DIRECTORY>

      - name: Result
        uses: actions/github-script@v6
        env:
            summary: "Result:\n${{ steps.po-linter.outputs.po-linter }}"
        with:
            github-token: ${{ secrets.GITHUB_TOKEN }}
            script: |
                const output = `#### Prometheus Operator Linting Results \`${{ steps.po-linter.outcome }}\`
                <details><summary>Show</summary>
                ${process.env.summary}
                </details>`
                github.rest.issues.createComment({
                  issue_number: context.issue.number,
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  body: output
                })
      - name: Exitcode
        if: steps.po-linter.outcome != 'success'
        run: exit 1

This page was last reviewed on 5 March 2025. It needs to be reviewed again on 5 September 2025 by the page owner #cloud-platform .