publish-image.yml

#
name: Create and publish a Docker image for Otel Collectors with Arrow

on:
  workflow_dispatch:
  pull_request:
    branches:
      - "**"
    paths:
      - "arrow/**"
      - "lightstep/**"
  push:
    branches:
      - main
    paths:
      - "arrow/**"
      - "lightstep/**"

# Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}/otelarrowcol
  PLATFORMS: linux/amd64,linux/arm64

# There is a single job in this workflow. It's configured to run on the latest available version of Ubuntu.
jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      # Uses the `docker/login-action` action to log in to the Container registry registry using the account and password that will publish the packages. Once published, the packages are scoped to the account defined here.
      - name: Log in to the Container registry
        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Read build config YAML and read/set otelcol version
        id: read-yaml
        run: |
          # Parse the YAML file and extract the otelcol version
          echo "otelcol_version=$(yq -r '.dist.otelcol_version' ./arrow/otelcolarrow-build.yaml)" >> $GITHUB_OUTPUT
      # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
        with:
          # TODO: remove -EXPERIMENTAL below.
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}-EXPERIMENTAL
          tags: |
            # Set the OTELCOL_VERSION here
            type=raw,value=${{ steps.read-yaml.outputs.otelcol_version }}
            # set latest tag for master branch
            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      - name: Cache Docker layers
        uses: actions/cache@v3
        with:
          path: /tmp/.buildx-cache
          key: ${{ runner.os }}-buildx-${{ github.sha }}
          restore-keys: |
            ${{ runner.os }}-buildx-
      # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
      # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
      - name: Build and push Docker image
        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
        with:
          context: ./arrow
          # Only push to GHCR if this change is off the main branch
          push: ${{ github.ref == format('refs/heads/{0}', 'main') }}
          # Build for all platforms specified.
          platforms: ${{ env.PLATFORMS }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=local,src=/tmp/.buildx-cache
          cache-to: type=local,dest=/tmp/.buildx-cache