# aws-lambda-alias-update

Composite action that updates Lambda function aliases from a Terraform output. Iterates over the `lambda_alias_updates` Terraform output and calls `aws lambda update-alias` for each entry.

**Example `lambda-alias-updates` input:**

```json
[
  "{\"alias_name\": \"live\", \"function_name\": \"my-get-product\", \"version\": \"42\"}",
  "{\"alias_name\": \"live\", \"function_name\": \"my-get-category\", \"version\": \"7\"}"
]
```

## Inputs

| Input | Required | Default | Description |
|-------|----------|---------|-------------|
| `lambda-alias-updates` | Yes | — | JSON array of Lambda alias update objects (Terraform output: `lambda_alias_updates`). Each element is a JSON-encoded string with `alias_name`, `function_name`, and `version`. |

## Usage

```yaml
- name: Update Lambda Aliases
  uses: https://schmalz-git.git.onstackit.cloud/schmalz/shared-actions/aws-lambda-alias-update@aws-lambda-alias-update-v1
  with:
    lambda-alias-updates: ${{ steps.tf-apply.outputs.lambda_alias_updates }}
```

## Terraform Setup

- Add the following content to the project
- Add all Lambda Modules to the `provisioned_lambda_modules` list for which the Function Alias and/or Provisioned Concurrency should be updated

**`output.tf`**
```tf
locals {
  // List of Lambda Modules that have provisioned concurrency configured.
  // Required to update the aliases of these functions after deployment.
  provisioned_lambda_modules = [
    module.lambda_get_category,
    module.lambda_product_get_full_slug,
    module.lambda_get_product,
  ]
}

// Output which allows Updates of Lambda Alias and Provisioned Concurrency
output "lambda_alias_updates" {
  value = concat([for module in local.provisioned_lambda_modules : "{\"alias_name\": \"${module.lambda_alias_name}\", \"function_name\": \"${module.lambda_name}\", \"version\": \"${module.lambda_version}\" }"])
}

```

## Example Usage with other Shared Actions

```yml
jobs:
  deploy-stage:
    name: Build and Deploy to Stage
    runs-on: stackit-ubuntu-22
    steps:
      - name: Apply Terraform
        uses: https://schmalz-git.git.onstackit.cloud/schmalz/shared-actions/terraform-apply@terraform-apply-v1
        id: tf-apply
        with:
          terraform-version: 1.14.9
          workspace: stage
          var-file: stage.tfvars
          jfrog-token: ${{ secrets.JFROG_TOKEN }}

      - name: Update Lambda Aliases
        uses: https://schmalz-git.git.onstackit.cloud/schmalz/shared-actions/aws-lambda-alias-update@aws-lambda-alias-update-v1
        with:
          lambda-alias-updates: ${{ steps.tf-apply.outputs.lambda_alias_updates }}

      - name: Wait for Lambda Provisioned Concurrency
        uses: https://schmalz-git.git.onstackit.cloud/schmalz/shared-actions/aws-lambda-wait-for-provisioned-concurrency@aws-lambda-wait-for-provisioned-concurrency-v1
        with:
          lambda-alias-updates: ${{ steps.tf-apply.outputs.lambda_alias_updates }}
```

## Notes

- Expects the `lambda-alias-updates` input to be the raw `lambda_alias_updates` output from the `terraform-apply` action.
- Requires AWS credentials to be configured in the job before this step runs.