GitOps Sync with Multiple Rollout Steps

Learn how to pass values between GitOps Rollout steps using Harness expressions

This advanced example demonstrates a complete pipeline that starts with a GitOps sync step followed by multiple GitOps Rollout steps, showing how to pass values between steps.

Overview

Harness provides a powerful expression system to access outputs from previous steps. This enables dynamic configuration where steps automatically discover and use the correct rollout details without hardcoding values.

Key Benefits

Dynamic Configuration: Steps automatically discover and use the correct rollout details
Reusability: The same pipeline can work across different environments and applications
Error Reduction: No hardcoded values that could become outdated
Maintainability: Changes to rollout names or namespaces are automatically reflected

Pipeline Overview

Here's a visual representation of the pipeline:

IMPORTANT

To use Argo Rollouts with Harness GitOps pipelines, ensure the CDS_GITOPS_ENABLE_ROLLOUTS_PIPELINE_UX feature flag is enabled in your Harness account.

This pipeline consists of the following key steps:

Update Rollout Image: Updates the image tag in your GitOps Application's manifest
GitOps Sync: Synchronizes the GitOps Application to apply the image update, which triggers a new rollout
Resume First Pause for Rollout: Resumes the rollout from the first pause step
Any Intermediate Steps: Optional placeholder steps for custom logic
Resume Second Pause for Rollout: Resumes the rollout from the second pause step
Handle Degraded Rollout: Handles degraded rollout states with retry action
Conditional Execution For Rollout: Conditional execution based on application name

Pipeline YAML

pipeline:
  name: RolloutStepExample
  identifier: RolloutStepExample
  projectIdentifier: projectidentifier
  orgIdentifier: default
  tags: {}
  stages:
    - stage:
        name: gs1
        identifier: gs1
        description: ""
        type: Deployment
        spec:
          deploymentType: Kubernetes
          gitOpsEnabled: true
          service:
            serviceRef: svc1
          execution:
            steps:
              - step:
                  type: UpdateGitOpsApp
                  name: Update Rollout Image
                  identifier: Update_Rollout_Image
                  spec:
                    targetRevision: master
                    kustomize:
                      images:
                        - argoproj/load-tester:latest
                        - argoproj/rollouts-demo:yellow
                      replicas: []
                    applicationName: app-rollout-example
                    agentId: qaargoagent
                  timeout: 10m
              - step:
                  type: GitOpsSync
                  name: GitOpsSync_1
                  identifier: GitOpsSync_1
                  spec:
                    prune: false
                    dryRun: false
                    applyOnly: false
                    forceApply: false
                    applicationsList:
                      - applicationName: app-rollout-example
                        agentId: qaargoagent
                    retryStrategy: {}
                    retry: false
                    syncOptions:
                      skipSchemaValidation: false
                      autoCreateNamespace: false
                      pruneResourcesAtLast: false
                      applyOutOfSyncOnly: false
                      replaceResources: false
                      prunePropagationPolicy: foreground
                  timeout: 10m
              - step:
                  type: GitOpsRollout
                  name: Resume First Pause for Rollout
                  identifier: Resume_First_Pause_for_Rollout
                  spec:
                    appName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].appName>
                    agentIdentifier: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].agentIdentifier>
                    namespace: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].namespace>
                    rolloutName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].rolloutName>
                    waitUntilHealthStatus:
                      healthStatus: Suspended
                    autoRolloutAction: resume
                  timeout: 10m
                  failureStrategies:
                    - onFailure:
                        errors:
                          - AllErrors
                        action:
                          type: Ignore
              - step:
                  type: Wait
                  name: Any intermediate steps
                  identifier: Any_intermediate_steps
                  spec:
                    duration: 30s
              - step:
                  type: GitOpsRollout
                  name: Resume Second Pause for Rollout
                  identifier: Resume_Second_Pause_for_Rollout
                  spec:
                    appName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].appName>
                    agentIdentifier: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].agentIdentifier>
                    namespace: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].namespace>
                    rolloutName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].rolloutName>
                    waitUntilHealthStatus:
                      healthStatus: Suspended
                    autoRolloutAction: resume
                  timeout: 10m
                  failureStrategies:
                    - onFailure:
                        errors:
                          - AllErrors
                        action:
                          type: Ignore
              - step:
                  type: GitOpsRollout
                  name: Handle Degraded Rollout
                  identifier: Handle_Degraded_Rollout
                  spec:
                    appName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].appName>
                    agentIdentifier: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].agentIdentifier>
                    namespace: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].namespace>
                    rolloutName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].rolloutName>
                    autoRolloutAction: retry
                  timeout: 10m
                  when:
                    stageStatus: Failure
              - step:
                  type: GitOpsRollout
                  name: Conditional Execution For Rollout
                  identifier: Conditional_Execution_For_Rollout
                  spec:
                    appName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].appName>
                    agentIdentifier: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].agentIdentifier>
                    namespace: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].namespace>
                    rolloutName: <+execution.steps.GitOpsSync_1.gitops.discoveredRollouts[0].rolloutName>
                    autoRolloutAction: restart
                  timeout: 10m
                  when:
                    stageStatus: All
                    condition: <+pipeline.stages.gs1.spec.execution.steps.GitOpsSync_1.gitops.applications[0].name>=="app-rollout-example"
            rollbackSteps: []
          environment:
            environmentRef: env1
            deployToAll: true
        tags: {}
        failureStrategies:
          - onFailure:
              errors:
                - AllErrors
              action:
                type: StageRollback

How to Get Values from Previous Steps

Harness provides a powerful expression system to access outputs from previous steps. Here's how it works:

1. Accessing GitOps Sync Outputs

The GitOps Sync step outputs discovered rollouts that can be used in subsequent steps:

<+execution.steps.<step_identifier>.gitops.discoveredRollouts[<index>].<field>>

Available fields:

agentIdentifier - The GitOps agent identifier
appName - The GitOps application name
rolloutName - The Rollout resource name
namespace - The namespace where the rollout is deployed

2. Expression Examples

# Get the first discovered rollout's agent <a href="#get-the-first-discovered-rollouts-agent" id="get-the-first-discovered-rollouts-agent"></a>
<+execution.steps.gitops_sync_step.gitops.discoveredRollouts[0].agentIdentifier>

# Get the rollout name <a href="#get-the-rollout-name" id="get-the-rollout-name"></a>
<+execution.steps.gitops_sync_step.gitops.discoveredRollouts[0].rolloutName>

# Get the namespace <a href="#get-the-namespace" id="get-the-namespace"></a>
<+execution.steps.gitops_sync_step.gitops.discoveredRollouts[0].namespace>

3. Multiple Rollouts

If you have multiple rollouts, access them by index:

# First rollout <a href="#first-rollout" id="first-rollout"></a>
<+execution.steps.gitops_sync_step.gitops.discoveredRollouts[0].rolloutName>

# Second rollout <a href="#second-rollout" id="second-rollout"></a>
<+execution.steps.gitops_sync_step.gitops.discoveredRollouts[1].rolloutName>

4. Accessing Other Step Outputs

You can also access outputs from other step types:

# Access shell script outputs <a href="#access-shell-script-outputs" id="access-shell-script-outputs"></a>
<+execution.steps.shell_step.output.outputVariables.VAR_NAME>

# Access HTTP response <a href="#access-http-response" id="access-http-response"></a>
<+execution.steps.http_step.output.responseBody>

# Access artifact information <a href="#access-artifact-information" id="access-artifact-information"></a>
<+execution.steps.build_step.output.artifactPath>

Step-by-Step Explanation

Step 1: Update Rollout Image

Purpose: Updates the container image in your GitOps Application's manifest
Configuration: Uses the UpdateGitOpsApp step to modify the image tag in the rollout manifest
Key Settings:
- targetRevision: Git branch containing your manifests
- kustomize.images: Specify the new image to deploy
- applicationName: Your GitOps Application name
- agentId: GitOps Agent identifier

Step 2: GitOps Sync

Purpose: Synchronizes the GitOps Application to apply the image update
Configuration: Uses the GitOpsSync step to trigger a sync operation
Key Settings:
- applicationsList: List of applications to sync
- syncOptions: Various sync configuration options
- timeout: Maximum time to wait for sync completion

Step 3: Resume First Pause for Rollout

Purpose: Resumes the rollout from the first pause step
Configuration: Uses the GitOpsRollout step with resume action
Key Settings:
- autoRolloutAction: Set to resume
- waitUntilHealthStatus: Set to Suspended to wait for pause state
- Uses expressions from the Sync step to get rollout details
- failureStrategies: Ignore errors to continue pipeline

Step 4: Any Intermediate Steps

Purpose: Placeholder for custom logic or additional processing
Configuration: Uses the Wait step for simple delays
Use Cases:
- Add custom validation logic
- Insert additional processing steps
- Create delays between operations

Step 5: Resume Second Pause for Rollout

Purpose: Resumes the rollout from the second pause step
Configuration: Uses the GitOpsRollout step with resume action
Key Settings:
- autoRolloutAction: Set to resume
- waitUntilHealthStatus: Set to Suspended to wait for pause state
- Uses expressions from the Sync step to get rollout details

Step 6: Handle Degraded Rollout

Purpose: Handles degraded rollout states with retry action
Configuration: Uses the GitOpsRollout step with retry action
Key Settings:
- autoRolloutAction: Set to retry
- when: Set to Failure to only run on stage failure
- Uses expressions from the Sync step to get rollout details

Step 7: Conditional Execution For Rollout

Purpose: Conditional execution based on application name
Configuration: Uses the GitOpsRollout step with restart action
Key Settings:
- autoRolloutAction: Set to restart
- when: Conditional execution with custom condition
- Uses expressions to check application name

Best Practices

Use descriptive step identifiers for easier reference
Add timeout values appropriate for your deployment size
Include health checks for critical production deployments
Consider manual approval steps for production environments
Test expressions in the pipeline editor before saving

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NextArgo Rollouts with Continuous Verification

Last updated 15 days ago

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