Validating build configuration with GitHub Actions

Build checks let you validate your docker build configuration without actually running the build.

Run checks with docker/build-push-action

To run build checks in a GitHub Actions workflow with the build-push-action, set the call input parameter to check. With this set, the workflow fails if any check warnings are detected for your build's configuration.

name: ci

on:
  push:

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Validate build configuration
        uses: docker/build-push-action@v6
        with:
          call: check

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          push: true
          tags: user/app:latest

Run checks with docker/bake-action

If you're using Bake and docker/bake-action to run your builds, you don't need to specify any special inputs in your GitHub Actions workflow configuration. Instead, define a Bake target that calls the check method, and invoke that target in your CI.

target "build" {
  dockerfile = "Dockerfile"
  args = {
    FOO = "bar"
  }
}
target "validate-build" {
  inherits = ["build"]
  call = "check"
}
name: ci

on:
  push:

env:
  IMAGE_NAME: user/app

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Validate build configuration
        uses: docker/bake-action@v5
        with:
          targets: validate-build

      - name: Build
        uses: docker/bake-action@v5
        with:
          targets: build
          push: true