Azure DevOps pipeline with multi-stage docker image layer caching support

azure-pipelines-build-docker-with-cache.yml

trigger:
- master

pool:
  vmImage: 'ubuntu-latest'

variables:
  imageRepository: 'multi-stage-build-caching'
  containerRegistry: 'ACR-Service-Connection-Name'
  registryName: '[redacted].azurecr.io'
  tag: '$(Build.BuildNumber)'

steps:
  - task: Docker@2
    displayName: "Registry Login"
    inputs:
      containerRegistry: '$(containerRegistry)'
      command: 'login'

  - script: "docker pull $(registryName)/$(imageRepository):latest-build && docker pull $(registryName)/$(imageRepository):latest"
    displayName: "Pull latest for layer caching"
    condition: ne(variables['USE_BUILD_CACHE'], 'false')
    continueOnError: true # for the first build, tags will not exist yet

  - task: Docker@2
    displayName: "Build - Builder Stage"
    inputs:
      containerRegistry: '$(containerRegistry)'
      repository: '$(imageRepository)'
      command: 'build'
      Dockerfile: './Dockerfile'
      buildContext: '.'
      arguments: '--target builder --cache-from=$(registryName)/$(imageRepository):latest-build'
      tags: |
        $(tag)-build
        latest-build

  - task: Docker@2
    displayName: "Build - Final Stage"
    inputs:
      containerRegistry: '$(containerRegistry)'
      repository: '$(imageRepository)'
      command: 'build'
      Dockerfile: './Dockerfile'
      buildContext: '.'
      arguments: '--cache-from=$(registryName)/$(imageRepository):latest-build --cache-from=$(registryName)/$(imageRepository):latest'
      tags: |
        $(tag)
        latest

  - task: Docker@2
    displayName: "Push image"
    inputs:
      command: push
      containerRegistry: "$(containerRegistry)"
      repository: $(imageRepository)
      tags: |
        $(tag)-build
        latest-build
        $(tag)
        latest

Great to hear 👍