Kubernetes Rolling Deploy

Prepare manifests, apply them to the cluster, and wait for all pods to reach steady state.

The Kubernetes Rolling Deploy step prepares your manifests, applies them to the cluster using kubectl apply, and waits for all pods to reach steady state. Kubernetes replaces pods incrementally using its native RollingUpdate strategy. Use this step in a rolling stage, or as the promotion step at the end of a canary stage.

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Before you begin

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

• A Kubernetes service: Go Kubernetes services to set up your service manifests and artifact source.

• A Kubernetes infrastructure: Go Kubernetes infrastructure to connect your cluster and namespace.

• A Harness delegate in the target cluster: The delegate runs deployment steps in the cluster.

• Runtime configuration: Every Kubernetes stage requires a runtime block specifying the connector and namespace. Go Kubernetes runtime configuration to understand the required fields.

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Configure the step

The following parameters are available on the Kubernetes Rolling Deploy step.

Parameter	Description	Required
Name	Display name for this step in the stage canvas. Default: Kubernetes Rolling Deploy.	Required
Skip Dry Run	When enabled, skips the kubectl apply --dry-run pre-validation before the actual apply. Default: false.	Optional
Kubernetes Pruning	When enabled, Harness removes resources from the cluster that exist in the previous release but are no longer in the current manifests. Default: false.	Optional
Manifest Path	Override the manifest paths from the service configuration. Leave empty to use all manifests from the service.	Optional
Kubeconfig Path	Path to the kubeconfig file. Default: ${{infra.kube_config_path}}.	Optional
Namespace	Target namespace for the deployment. Default: ${{infra.namespace}}.	Optional
Release Name	Name used to track Harness release history in the cluster. Default: ${{infra.releaseName}}.	Optional
Log Level	Verbosity of step logs. Default: info.	Optional

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How the step works

When the step runs, it performs three internal actions:

1. Kubernetes Rolling Prepare Action: Reads your manifests, increments the release number, versions ConfigMaps and Secrets, labels all pods with harness.io/track=stable, and writes the prepared manifests to the workspace. Harness saves the release state as a Kubernetes Secret in the target namespace.

2. Kubernetes Apply Action: Applies the prepared manifests to your cluster using kubectl apply. Kubernetes performs the rolling update natively, incrementally replacing old pods with new pods according to the maxSurge and maxUnavailable settings in your Deployment manifest.

3. Kubernetes Steady State Check Action: Polls the cluster until all pods in the Deployment reach Running status and pass readiness checks, or until the step timeout is reached.

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Advanced settings

• Timeout duration: Maximum time the step is allowed to run before being terminated.

• 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.

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Next steps

• Go Kubernetes rolling deployment to understand the full rolling deployment flow.

• Go Kubernetes Rolling Rollback to configure the rollback step for this strategy.