Docker Layer Cache on GitHub Actions

build.yml

name: build

on:
  push:
    branches:
      - main

env:
  ECR_REPOSITORY: reireias2021-rails
  DOCKER_BUILDKIT: 1

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v1

      - uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: ap-northeast-1

      - name: Login to Amazon ECR
        id: login-ecr
        uses: aws-actions/amazon-ecr-login@v1

      - name: Build and Push
        uses: docker/build-push-action@v2
        env:
          ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
        with:
          push: true
          cache-from: |
            type=registry,ref=${{ env.ECR_REGISTRY }}/${{ env.ECR_REPOSITORY }}:builder
          tags: |
            ${{ env.ECR_REGISTRY }}/${{ env.ECR_REPOSITORY }}:${{ github.sha }}
            ${{ env.ECR_REGISTRY }}/${{ env.ECR_REPOSITORY }}:latest

      - name: Save builder cache
        uses: docker/build-push-action@v2
        env:
          ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
        with:
          target: builder
          push: true
          build-args: |
            BUILDKIT_INLINE_CACHE=1
          tags: |
            ${{ env.ECR_REGISTRY }}/${{ env.ECR_REPOSITORY }}:builder