Using the AWS SAM CLI with Terraform for local debugging and testing (original) (raw)
This topic covers how to use supported AWS Serverless Application Model Command Line Interface (AWS SAM CLI) commands with your Terraform projects and Terraform Cloud.
To provide feedback and submit feature requests, create a GitHub Issue.
Topics
- Local testing with sam local invoke
- Local testing with sam local start-api
- Local testing with sam local start-lambda
- Terraform limitations
Local testing with sam local invoke
The following is an example of testing your Lambda function locally by passing in an event:
$ sam local invoke --hook-name terraform hello_world_function -e events/event.json -To learn more about using this command, see Introduction to testing with sam local invoke.
Local testing with sam local start-api
To use sam local start-api with Terraform, run the following:
$ sam local start-api --hook-name terraformThe following is an example:
$ sam local start-api --hook-name terraform
Running Prepare Hook to prepare the current application
Executing prepare hook of hook "terraform"
Initializing Terraform application
...
Creating terraform plan and getting JSON output
....
Generating metadata file
Unresolvable attributes discovered in project, run terraform apply to resolve them.
Finished generating metadata file. Storing in...
Prepare hook completed and metadata file generated at: ...
Mounting HelloWorldFunction at http://127.0.0.1:3000/hello [GET]
Mounting None at http://127.0.0.1:3000/hello [POST]
You can now browse to the above endpoints to invoke your functions. You do not need to restart/reload SAM CLI while working on your functions, changes will be reflected instantly/automatically. If you
used sam build before running local commands, you will need to re-run sam build for the changes to be picked up. You only need to restart SAM CLI if you update your AWS SAM template
2023-06-26 13:21:20 * Running on http://127.0.0.1:3000/ (Press CTRL+C to quit)To learn more about this command, see Introduction to testing with sam local start-api.
For Lambda functions configured to use Lambda authorizers, the AWS SAM CLI will automatically invoke your Lambda authorizer before invoking your Lambda function endpoint.
- To learn more about this feature in the AWS SAM CLI, see Lambda functions that use Lambda authorizers.
- For more information on using Lambda authorizers in Terraform, see Resource: aws_api_gateway_authorizer in the Terraform registry.
Local testing with sam local start-lambda
The following is an example of testing your Lambda function locally with the AWS Command Line Interface (AWS CLI):
- Use the AWS SAM CLI to create a local testing environment:
$ sam local start-lambda --hook-name terraform hello_world_function - Use the AWS CLI to invoke your function locally:
$ aws lambda invoke --function-name hello_world_function --endpoint-url http://127.0.0.1:3001/ response.json --cli-binary-format raw-in-base64-out --payload file://events/event.json To learn more about this command, see Introduction to testing with sam local start-lambda.
Terraform limitations
The following are limitations when using the AWS SAM CLI with Terraform:
- Lambda functions linked to multiple layers.
- Terraform local variables that define links between resources.
- Referencing a Lambda function that hasn’t been created yet. This includes functions that are defined in the body attribute of the REST API resource.
To avoid these limitations, you can run terraform apply when a new resource is added.