Publish Container image workflow (webpro/reveal-md)

The Publish Container image workflow from webpro/reveal-md, explained and optimized by Latchkey.

What it does

This is the Publish Container image workflow from the webpro/reveal-md 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

---
name: Publish Container image

on:
  workflow_dispatch:
  push:
    branches:
      - 'main'
    tags:
      - '*'

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Set up QEMU
        uses: docker/setup-qemu-action@v2

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      - name: Populate Docker metadata
        id: meta
        uses: docker/metadata-action@v4
        with:
          images: webpronl/reveal-md
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}

      - name: Login to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_TOKEN }}

      - name: Build and push
        uses: docker/build-push-action@v4
        with:
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          provenance: false

The same workflow, on Latchkey

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

---
name: Publish Container image
 
on:
  workflow_dispatch:
  push:
    branches:
      - 'main'
    tags:
      - '*'
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
    runs-on: latchkey-small
 
    steps:
      - name: Set up QEMU
        uses: docker/setup-qemu-action@v2
 
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
 
      - name: Populate Docker metadata
        id: meta
        uses: docker/metadata-action@v4
        with:
          images: webpronl/reveal-md
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
 
      - name: Login to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_TOKEN }}
 
      - name: Build and push
        uses: docker/build-push-action@v4
        with:
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          provenance: false
 

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