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Helm Blue Green Deploy

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The Helm Blue Green Deploy step deploys a new version of your chart to the stage side of a blue-green deployment and waits for the new workloads to reach steady state. The primary service continues routing all production traffic to the existing workload until the Helm Blue Green Swap step runs.

Before you begin​

Before you configure the step, make sure you have the following in place:

  • A Helm service: Go Helm services to set up a service with a chart source and values files.
  • A Helm infrastructure: Go Helm infrastructure to connect a cluster and namespace.
  • A Harness delegate in the target cluster: The delegate runs the deployment steps in the cluster.
  • Runtime configuration: Every Helm stage requires a runtime block specifying a connector and namespace. Go Helm runtime configuration to understand the required fields.

Configure the step​

The following parameters are available on the Helm Blue Green Deploy step.

ParameterDescriptionRequired
NameDisplay name for this step in the stage canvas. Default: Helm Blue Green Deploy.Required
Ignore Failed Release HistoryWhen enabled, proceeds with deployment even if the previous Helm release has a failed status. Use this to recover from a broken release without manual cleanup. Default: false.Optional
Skip Steady State CheckWhen enabled, skips waiting for the new workloads to reach ready status after deployment. Default: false.Optional
Run Chart TestsWhen enabled, runs helm test against the new release after a successful deployment. Default: false.Optional
Skip CleanupWhen enabled, skips cleanup of a failed first release. Use this to inspect resources left behind after a failed initial install. Default: false.Optional
Print ManifestsWhen enabled, logs the full rendered chart manifest to the step output with secrets redacted. Default: false.Optional
Server-Side RenderingWhen enabled, passes --server to helm template so manifests are rendered against the live cluster rather than locally. Default: false.Optional
Environment VariablesAdditional environment variables to pass into the Helm plugin execution.Optional
Command FlagsAdditional flags to append to the helm upgrade command, for example --atomic or --cleanup-on-fail.Optional

How the step works​

When the step runs, it performs the following actions in order:

  1. Input validation: Resolves and prints all input parameters. Prints PARAM VALIDATION: All looks good before proceeding.

  2. Service detection: Reads the existing Helm release manifest and locates the stage service using the harness.io/service-type: stage label and the primary service using the harness.io/service-type: primary label.

  3. Helm upgrade: Runs helm upgrade --install with the new chart version. The step deploys the new workload alongside the existing one. The step updates the stage service selector to route to the new workload; the primary service continues pointing to the existing workload unchanged.

  4. Steady state check: Polls the cluster until the new workloads reach ready status. The step skips this check if Skip Steady State Check is enabled.

Step outputs​

The following output variables are available for use in downstream steps.

Output variableDescription
stableServiceThe name of the service currently routing production traffic. Auto-populates the Helm Blue Green Swap step.
stageServiceThe name of the service currently routing stage traffic. Auto-populates the Helm Blue Green Swap step.

Advanced settings​

  • Timeout duration: Maximum time the step can run before Harness terminates it.
  • On failure: Define what happens if the step fails, such as retry, mark as success, or abort.
  • Strategy: Configure a looping strategy to run this step over a list of values.
  • Conditional execution: Run this step only when a specified condition is true.

Next steps​

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