Publish Docker image workflow (Diaoul/subliminal)

The Publish Docker image workflow from Diaoul/subliminal, explained and optimized by Latchkey.

CI health: C - fair

Point runs-on at Latchkey and get run de-duplication, job timeouts, SHA-pinned actions, self-healing for flaky steps, and up to 58% lower cost, applied automatically.

Grade your own workflow free or run it on Latchkey →

Source: Diaoul/subliminal.github/workflows/docker-build.yamlLicense MITView source

What it does

This is the Publish Docker image workflow from the Diaoul/subliminal repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

workflow (.yml)

name: Publish Docker image

on:
  push:
    branches:
      - main
    tags:
      - "*.*.*"
  workflow_call:
    inputs:
      tag-name:
        description: 'Tag name'
        required: true
        type: 'string'
  workflow_dispatch:
    inputs:
      tag-name:
        description: 'Tag name'
        required: true
        type: 'string'
  pull_request:

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  TEST_IMAGE: subliminal

jobs:
  build-docker:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - name: Checkout repository
        if: github.event_name == 'push' || github.event_name == 'pull_request'
        uses: actions/checkout@v7
        with:
          persist-credentials: false
      - name: Checkout repository
        if: github.event_name == 'workflow_call' || github.event_name == 'workflow_dispatch'
        uses: actions/checkout@v7
        with:
          ref: ${{ inputs.tag-name }}
          persist-credentials: false

      - name: Set up QEMU
        if: |
          github.event_name == 'push'
          || github.event_name == 'workflow_call'
          || github.event_name == 'workflow_dispatch'
        uses: docker/setup-qemu-action@v4

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4
        with:
          cache-binary: false

      - name: Log in to the Container registry
        uses: docker/login-action@v4
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}},enable=${{ !startsWith(github.ref, 'refs/tags/0.') }}

      - name: Test building Docker image
        uses: docker/build-push-action@v7
        if: github.event_name == 'pull_request'
        with:
          context: .
          load: true
          tags: ${{ env.TEST_IMAGE }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Build and push Docker image
        uses: docker/build-push-action@v7
        if: |
          github.event_name == 'push'
          || github.event_name == 'workflow_call'
          || github.event_name == 'workflow_dispatch'
        with:
          context: .
          platforms: linux/amd64,linux/arm64,linux/arm/v7
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

# vim:ts=2:sw=2:et

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

name: Publish Docker image
 
on:
  push:
    branches:
      - main
    tags:
      - "*.*.*"
  workflow_call:
    inputs:
      tag-name:
        description: 'Tag name'
        required: true
        type: 'string'
  workflow_dispatch:
    inputs:
      tag-name:
        description: 'Tag name'
        required: true
        type: 'string'
  pull_request:
 
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  TEST_IMAGE: subliminal
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build-docker:
    timeout-minutes: 30
    runs-on: latchkey-small
    permissions:
      contents: read
      packages: write
 
    steps:
      - name: Checkout repository
        if: github.event_name == 'push' || github.event_name == 'pull_request'
        uses: actions/checkout@v7
        with:
          persist-credentials: false
      - name: Checkout repository
        if: github.event_name == 'workflow_call' || github.event_name == 'workflow_dispatch'
        uses: actions/checkout@v7
        with:
          ref: ${{ inputs.tag-name }}
          persist-credentials: false
 
      - name: Set up QEMU
        if: |
          github.event_name == 'push'
          || github.event_name == 'workflow_call'
          || github.event_name == 'workflow_dispatch'
        uses: docker/setup-qemu-action@v4
 
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4
        with:
          cache-binary: false
 
      - name: Log in to the Container registry
        uses: docker/login-action@v4
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
 
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}},enable=${{ !startsWith(github.ref, 'refs/tags/0.') }}
 
      - name: Test building Docker image
        uses: docker/build-push-action@v7
        if: github.event_name == 'pull_request'
        with:
          context: .
          load: true
          tags: ${{ env.TEST_IMAGE }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
 
      - name: Build and push Docker image
        uses: docker/build-push-action@v7
        if: |
          github.event_name == 'push'
          || github.event_name == 'workflow_call'
          || github.event_name == 'workflow_dispatch'
        with:
          context: .
          platforms: linux/amd64,linux/arm64,linux/arm/v7
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
 
# vim:ts=2:sw=2:et

What changed

Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
Cancel superseded runs when a branch or PR gets a newer push.
Add a job timeout so a hung step cannot burn hours of runner time.

5 third-party actions are referenced by a movable tag. Pin them to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

What Latchkey heals here

This workflow has steps that commonly fail on transient issues (network, registries, flaky browsers). On Latchkey managed runners they are detected, retried, and self-healed instead of failing your build:

Container pulls and builds

This workflow runs 1 job per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow

actions/checkout docker/setup-qemu-action docker/setup-buildx-action docker/login-action docker/metadata-action docker/build-push-action