reusable-list-packages.yml

name: Reusable workflow for listing changed packages

on:

  workflow_call:

    inputs:
      basedir:
        type: string
        description: Packages base directory path
        default: packages
      ref:
        type: string
        description: Git reference to compare HEAD with
        default: HEAD~1

    outputs:
      basedir:
        value: ${{ inputs.basedir }}
      all:
        value: ${{ jobs.list-packages.outputs.all }}
      crossplane:
        value: ${{ jobs.list-packages.outputs.crossplane }}
      carvel:
        value: ${{ jobs.list-packages.outputs.carvel }}
      crossplane_publish:
        value: ${{ jobs.list-packages.outputs.crossplane_publish }}
      carvel_publish:
        value: ${{ jobs.list-packages.outputs.carvel_publish }}

jobs:

  list-packages:

    runs-on: ubuntu-latest

    outputs:
      all: ${{ steps.list.outputs.packages }}
      crossplane: ${{ steps.filter.outputs.crossplane }}
      carvel: ${{ steps.filter.outputs.carvel }}
      crossplane_publish: ${{ steps.filter.outputs.crossplane_publish }}
      carvel_publish: ${{ steps.filter.outputs.carvel_publish }}

    steps:
      - name: Checkout
        uses: actions/checkout@v3
        with:
          fetch-depth: '0'

      # Prepare a list of changed files between $GIT_REF (default: HEAD~1) and HEAD
      # that match a specific pattern: BASEDIR/PROVIDER/PACKAGING/NAME/*
      # BASEDIR is set to 'packages' by default
      # PROVIDER can be the Cloud name ("aws", "azure", "gcp"), "multicloud" in case the package spans multiple clouds/platforms or free-form string (for example, "helm")
      # PACKAGING can currently support either "crossplane" or "carvel"
      # NAME is the package's name

      # The `git diff-tree` command outputs a list of file paths starting from the root of the repo, one per line,
      # that have been either Added, Copied, Modified or Renamed (ACMR).
      # This list is fed to `jq` that transforms it into an actual json array, filters by the entries that start with "BASEDIR/"
      # and strip the prefix.
      # Each entry is then tokenised by /, morphed into an object with "provider" key set as the first token, "packaging" as the second one, "name" as the third one
      # and the "path" as them all back together.
      # The resulting array is then purged of the duplicates and then set as value for the "include" key in a new object,
      # in order to meet https://docs.github.com/en/actions/using-jobs/using-a-matrix-for-your-jobs#expanding-or-adding-matrix-configurations.
      # The result is appended to GITHUB_OUTPUT as well as written to the workflow's output for debugging purposes (thus the `tee -a`).
      - name: List packages that have changed
        id: list
        run: |
          packages=$(git diff-tree --name-only -r --diff-filter=ACMR ${GIT_REF} HEAD | jq -ncrR --arg BASEDIR ${BASEDIR%%/} '
            [inputs]
            | map(capture("^"+$BASEDIR+"/(?<p>.*)$").p
              | split("/")
              | { "path": .[0:3]|join("/"), "provider": .[0], "packaging": .[1], "name": .[2] }
            )
            | map(select(.provider!=null and .packaging!=null and .name!=null))
            | unique
            | { "include": . }
          ')
          echo "packages=${packages}" | tee -a $GITHUB_OUTPUT
        env:
          BASEDIR: ${{ inputs.basedir }}
          GIT_REF: ${{ inputs.ref }}

      # Filter packages by packaging system, in order to feed them to different workflows for publishing and testing.
      # The $PACKAGES variable is filled with the result from the previous step and filtered using `jq` based on the "packaging" key.
      # Currently, only "crossplane" and "carvel" are supported and therefore only those outputs are provided, and contain
      # the list of packages per packaging system that have changed (as value of the "include" key as before).
      # Boolean outputs are also provided ("crossplane_publish" or "carvel_publish") to tell whether the above list has at least 1 item or not.
      - name: Filter packages
        id: filter
        run: |
          crossplane=$(jq -c '.include|=map(select(.packaging=="crossplane"))' <<< $PACKAGES)
          echo "crossplane=${crossplane}" | tee -a $GITHUB_OUTPUT
          echo "crossplane_publish=$(jq '.include|length > 0' <<<${crossplane})" | tee -a $GITHUB_OUTPUT

          carvel=$(jq -c '.include|=map(select(.packaging=="carvel"))' <<< $PACKAGES)
          echo "carvel=${carvel}" | tee -a $GITHUB_OUTPUT
          echo "carvel_publish=$(jq '.include|length > 0' <<<${carvel})" | tee -a $GITHUB_OUTPUT
        env:
          PACKAGES: ${{ steps.list.outputs.packages }}