Azure Pipelines

# ===== The model =====
# - Pipelines defined in azure-pipelines.yml
# - Stages -> Jobs -> Steps
# - Agent: where the job runs (Microsoft-hosted or self-hosted)

# ===== Minimal pipeline (Node) =====
# azure-pipelines.yml
trigger:
  branches: { include: [main] }

pool:
  vmImage: 'ubuntu-latest'

variables:
  NODE_VERSION: '20.x'

steps:
  - task: NodeTool@0
    inputs: { versionSpec: $(NODE_VERSION) }
  - script: npm ci
    displayName: 'Install'
  - script: npm run lint
    displayName: 'Lint'
  - script: npm test -- --coverage
    displayName: 'Test'
  - script: npm run build
    displayName: 'Build'
  - task: PublishTestResults@2
    inputs:
      testResultsFormat: 'JUnit'
      testResultsFiles: '**/junit.xml'

# ===== Stages =====
stages:
  - stage: Build
    jobs:
      - job: Build
        steps:
          - script: npm ci && npm run build
  - stage: Test
    dependsOn: Build
    jobs:
      - job: UnitTest
      - job: E2ETest
  - stage: Deploy
    dependsOn: Test
    condition: succeeded()
    jobs:
      - deployment: ToProd
        environment: production
        strategy:
          runOnce:
            deploy:
              steps:
                - script: ./deploy.sh

# ===== Matrix =====
jobs:
  - job: TestMatrix
    strategy:
      matrix:
        node18: { NODE_VERSION: '18.x' }
        node20: { NODE_VERSION: '20.x' }
        node22: { NODE_VERSION: '22.x' }
    steps:
      - task: NodeTool@0
        inputs: { versionSpec: $(NODE_VERSION) }
      - script: npm test

# ===== Templates (reuse across pipelines) =====
# .ci/build-and-test.yml
parameters:
  - name: nodeVersion
    type: string
    default: '20.x'
steps:
  - task: NodeTool@0
    inputs: { versionSpec: ${{ parameters.nodeVersion }} }
  - script: npm ci && npm test

# Use:
- template: .ci/build-and-test.yml
  parameters: { nodeVersion: '20.x' }

# ===== Variables + secrets =====
# UI: Pipeline -> Variables (mark as secret)
# YAML reference:
- script: echo $(MY_SECRET)
  env:
    MY_SECRET: $(MY_SECRET)

# Variable groups for sharing across pipelines:
variables:
  - group: prod-secrets

# ===== Approvals + gates =====
# Configure via Environment 'production':
#   - Required reviewers
#   - Branch restrictions
#   - Service health checks
# The deployment job pauses until approval is granted.

# ===== Self-hosted agents =====
# Install agent on your VM / k8s pool; register it.
# Useful for private networks, custom hardware, GPU builds.

pool:
  name: 'self-hosted'
  demands:
    - Agent.OS -equals Linux

# ===== Artifacts =====
- task: PublishPipelineArtifact@1
  inputs: { targetPath: 'dist', artifact: 'web-bundle' }

# Consume in a downstream job:
- task: DownloadPipelineArtifact@2
  inputs: { artifact: 'web-bundle', path: '$(Build.SourcesDirectory)/dist' }

# ===== Useful tasks =====
# AzureCLI@2          run az commands with service principal
# Docker@2             docker build / push
# KubernetesManifest   apply manifests
# AzureWebApp          deploy to App Service
# AzureFunctionApp     deploy to Functions

# ===== Patterns to internalise =====
# - YAML pipelines in the repo; do not use Classic editor
# - Templates for reuse across services
# - Environment approvals on prod
# - Required status checks on the default branch

# ===== Pitfalls =====
# - Secrets in plain YAML
# - Pipelines longer than 30 min -> people batch commits
# - 'latest' container tags in deploy -> non-reproducible
# - Classic builds + YAML mixed in one repo

# azure-pipelines.yml
trigger: [main]
pool: { vmImage: ubuntu-latest }
steps:
    - task: NodeTool@0
      inputs: { versionSpec: '20.x' }
    - script: npm ci && npm test