AWS Lambda Rolling Rollback

Restore a Lambda function to its previous version after a failed rolling deployment.

The AWS Lambda Rolling Rollback step redeploys the previous function version after a failed rolling deployment. Harness adds this step automatically to the rollback section of a rolling stage. It runs automatically when the Rolling Deploy step fails.

---

Step YAML

- name: AWS Lambda Rolling Rollback
  id: awsLambdaRollingRollbackStep
  template:
    uses: awsLambdaRollingRollbackStep

The step uses no explicit with: inputs — infrastructure is resolved automatically from the stage context.

---

Before you begin

• This step is automatically added to rolling stages. You do not need to add it manually unless you are building a custom rollback flow.

• A Lambda infrastructure with an AWS connector and region. Go to Lambda infrastructure.

---

Configure the step

Infrastructure Configuration

All values are derived from the infrastructure definition.

Field	Value	Description
AWS Connector	${{infra.connectorRef}}	The AWS connector resolved from the infrastructure definition. Used to authenticate to Lambda and restore the previous version.
AWS Region	${{infra.region}}	The AWS region resolved from the infrastructure definition.

---

What the step does

The rollback step reads state from the last successful execution of this stage — not from the failed run. When it runs:

1. Reads the function name and previous version number from the last successful stage execution.

2. Re-deploys the function to that version.

3. If the service included an alias definition (AwsLambdaFunctionAliasDefinition), also repoints the alias back to the restored version at 100% weight. If no alias was involved, only the function version is restored.

---

Advanced settings

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

• On failure: Define what happens if the rollback step itself fails.

• Strategy: Configure a looping strategy.

• Conditional execution: Run this step only when a condition is true.

---

Next steps

• Go to Lambda rolling deployment for the full rolling flow, including when rollback triggers.

• Go to AWS Lambda Rolling Deploy for the deploy step that this step rolls back.