Harness CI

Harness CI Skill

Container-native CI builds with test intelligence, caching, parallelization, and infrastructure management.

Build Infrastructure

• Cloud (Recommended): Zero-config hosted, auto-scaling, pre-installed tools

  infrastructure:
    type: Cloud
    spec:
      os: Linux  # Linux, MacOS, Windows
  

• Kubernetes: Self-hosted via k8s clusters

  infrastructure:
    type: KubernetesDirect
    spec:
      connectorRef: k8s_connector
      namespace: harness-builds
      os: Linux
  

• VMs: AWS, Azure, GCP pool-based scaling

Basic Pipeline Structure

pipeline:
  name: Build Pipeline
  identifier: build_pipeline
  properties:
    ci:
      codebase:
        connectorRef: harness_code
        repoName: my-service
        build: <+input>
  stages:
    - stage:
        name: Build and Test
        type: CI
        spec:
          cloneCodebase: true
          infrastructure:
            type: Cloud
            spec:
              os: Linux
          execution:
            steps:
              - step:
                  name: Install
                  type: Run
                  spec:
                    shell: Sh
                    command: npm ci
              - step:
                  name: Test
                  type: Run
                  spec:
                    command: npm test -- --coverage
              - step:
                  name: Build
                  type: Run
                  spec:
                    command: npm run build

Step Types

Run: Execute shell commands

- step:
    name: Build
    type: Run
    spec:
      shell: Sh
      command: npm run build
      envVariables:
        NODE_ENV: production
      resources:
        limits:
          memory: 2Gi
          cpu: "1"

RunTests (Test Intelligence): Language/framework-aware test execution

- step:
    type: RunTests
    spec:
      language: Java  # Java, Kotlin, Scala, C#, Python, Ruby
      buildTool: Maven  # Maven, Gradle, Bazel, etc.
      runOnlySelectedTests: true  # Enable TI
      enableTestSplitting: true   # Parallel execution
      testAnnotations: org.junit.Test
      packages: com.myapp

Docker Registry Build/Push

- step:
    name: Build and Push
    type: BuildAndPushDockerRegistry
    spec:
      connectorRef: docker_connector
      repo: myorg/myapp
      tags: [<+pipeline.sequenceId>, <+codebase.shortCommitSha>, latest]
      dockerfile: Dockerfile
      caching: true
      buildArgs:
        VERSION: <+pipeline.sequenceId>

ECR/GCR/ACR: Replace BuildAndPushDockerRegistry with BuildAndPushECR, BuildAndPushGCR, or BuildAndPushACR with appropriate connector refs.

Caching

S3 Cache:

- step:
    name: Save Cache
    type: SaveCacheS3
    spec:
      connectorRef: aws_connector
      bucket: harness-cache
      key: npm-{{ checksum "package-lock.json" }}
      sourcePaths: [node_modules]
- step:
    name: Restore Cache
    type: RestoreCacheS3
    spec:
      connectorRef: aws_connector
      bucket: harness-cache
      key: npm-{{ checksum "package-lock.json" }}
      failIfKeyNotFound: false

GCS Cache: Replace S3 steps with SaveCacheGCS/RestoreCacheGCS.

Parallelism

Matrix Strategy: Run steps with multiple configurations

- step:
    name: Test Matrix
    type: Run
    spec:
      command: npm test
      envVariables:
        NODE_VERSION: <+matrix.nodeVersion>
        DB_TYPE: <+matrix.database>
    strategy:
      matrix:
        nodeVersion: ["16", "18", "20"]
        database: [postgres, mysql]
      maxConcurrency: 4

Parallelism: Run same step multiple times

- step:
    name: Parallel Tests
    type: Run
    spec:
      command: npm test -- --shard=$HARNESS_STAGE_INDEX/$HARNESS_STAGE_TOTAL
    strategy:
      parallelism: 4

Parallel Step Groups:

- stepGroup:
    name: Parallel Build
    steps:
      - parallel:
          - step:
              name: Build Frontend
              type: Run
              spec:
                command: npm run build:frontend
          - step:
              name: Build Backend
              type: Run
              spec:
                command: npm run build:backend

Background Services

Start services (databases, caches) for integration tests:

- step:
    name: PostgreSQL
    type: Background
    spec:
      image: postgres:14
      envVariables:
        POSTGRES_USER: test
        POSTGRES_PASSWORD: test
        POSTGRES_DB: testdb
      portBindings:
        "5432": "5432"
      resources:
        limits:
          memory: 1Gi

- step:
    name: Wait for DB
    type: Run
    spec:
      command: until pg_isready -h localhost -p 5432; do sleep 1; done

Plugins & Actions

Slack Notification:

- step:
    name: Notify Slack
    type: Plugin
    spec:
      image: plugins/slack
      settings:
        webhook: <+secrets.getValue("slack_webhook")>
        channel: builds
        template: "Build {{#success build.status}}succeeded{{else}}failed{{/success}}"

S3 Upload:

- step:
    name: Upload Artifacts
    type: Plugin
    spec:
      image: plugins/s3
      settings:
        bucket: build-artifacts
        source: dist/**/*
        target: builds/<+pipeline.sequenceId>

GitHub Actions:

- step:
    name: Setup Node
    type: Action
    spec:
      uses: actions/setup-node@v3
      with:
        node-version: "18"
        cache: npm

Artifact Management

Upload build outputs to cloud storage:

• S3: Type S3Upload, spec: bucket, sourcePath, target
• GCS: Type GCSUpload, spec: bucket, sourcePath, target

CI Expressions

Triggers

Push Trigger:

trigger:
  name: Build on Push
  pipelineIdentifier: build_pipeline
  source:
    type: Webhook
    spec:
      type: Push
      connectorRef: harness_code
      repoName: my-service
      payloadConditions:
        - key: targetBranch
          operator: In
          value: [main, develop]

Pull Request & Tag: Use type: PullRequest or type: Tag with actions or tagCondition.

Troubleshooting

Debug:

- step:
    name: Debug
    type: Run
    spec:
      command: |
        echo "Branch: <+codebase.branch>"
        echo "Build: <+pipeline.sequenceId>"
        env | sort
        df -h

Related Documentation

• Harness CI Docs
• Test Intelligence
• Caching
• Build Infrastructure