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

Expression Description

<+codebase.branch>

Git branch name

<+codebase.commitSha>

Full commit SHA

<+codebase.shortCommitSha>

Short SHA (7 chars)

<+codebase.commitMessage>

Commit message

<+pipeline.sequenceId>

Build number

<+pipeline.executionId>

Execution UUID

<+secrets.getValue("key")>

Secret value

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

Issue Solution

Build timeout Increase timeout, optimize steps

Cache miss Verify checksum file path

Image pull failed Check connector credentials

TI not working Verify language/buildTool config

Out of memory Increase step memory limits

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