This project contains source code and supporting files for a serverless application that you can deploy with the SAM CLI. It is an implementation with lambda layers and Middy, a middleware framework for serverless.
Test a single function by invoking it directly with a test event. An event is a JSON document that represents the input that the function receives from the event source. Test events are included in the
events folder in this project.
Run functions locally and invoke them with the
sam local invoke command.
aws-sam-middy-app$ sam local invoke "ProductsFunction" --event events/event.json
The SAM CLI can also emulate your application's API. Use the
sam local start-api to run the API locally on port 3000.
aws-sam-middy-app$ sam local start-api aws-sam-middy-app$ curl http://localhost:3000/
Deploy the sample application
The Serverless Application Model Command Line Interface (SAM CLI) is an extension of the AWS CLI that adds functionality for building and testing Lambda applications. It uses Docker to run your functions in an Amazon Linux environment that matches Lambda. It can also emulate your application's build environment and API.
To use the SAM CLI, you need the following tools.
- AWS CLI - Install the AWS CLI and [configure it with your AWS credentials].
- SAM CLI - Install the SAM CLI
- Node.js - Install Node.js 10, including the NPM package management tool.
- Docker - Install Docker community edition
The SAM CLI uses an Amazon S3 bucket to store your application's deployment artifacts. If you don't have a bucket suitable for this purpose, create one. Replace
BUCKET_NAME in the commands in this section with a unique bucket name.
aws-sam-middy-app$ aws s3 mb s3://BUCKET_NAME
To prepare the application for deployment, use the
sam package command.
aws-sam-middy-app$ sam package \ --output-template-file packaged.yaml \ --s3-bucket BUCKET_NAME
The SAM CLI creates deployment packages, uploads them to the S3 bucket, and creates a new version of the template that refers to the artifacts in the bucket.
To deploy the application, use the
sam deploy command.
aws-sam-middy-app$ sam deploy \ --template-file packaged.yaml \ --stack-name aws-sam-middy-app \ --capabilities CAPABILITY_IAM
After deployment is complete you can run the following command to retrieve the API Gateway Endpoint URL:
aws-sam-middy-app$ aws cloudformation describe-stacks \ --stack-name aws-sam-middy-app \ --query 'Stacks.Outputs[?OutputKey==`HelloWorldApi`]' \ --output table
Use the SAM CLI to build and test locally
Build your application with the
sam build command.
aws-sam-middy-app$ sam build
The SAM CLI installs dependencies defined in
common-layer/package.json, creates a deployment package, and saves it in the
The SAM CLI reads the application template to determine the API's routes and the functions that they invoke. The
Events property on each function's definition includes the route and method for each path.
Events: Products: Type: Api Properties: Path: /products Method: get
Add a resource to your application
The application template uses AWS Serverless Application Model (AWS SAM) to define application resources. AWS SAM is an extension of AWS CloudFormation with a simpler syntax for configuring common serverless application resources such as functions, triggers, and APIs. For resources not included in the SAM specification, you can use standard AWS CloudFormation resource types.
Fetch, tail, and filter Lambda function logs
To simplify troubleshooting, SAM CLI has a command called
sam logs lets you fetch logs generated by your deployed Lambda function from the command line. In addition to printing the logs on the terminal, this command has several nifty features to help you quickly find the bug.
NOTE: This command works for all AWS Lambda functions; not just the ones you deploy using SAM.
aws-sam-middy-app$ sam logs -n HelloWorldFunction --stack-name aws-sam-middy-app --tail
You can find more information and examples about filtering Lambda function logs in the SAM CLI Documentation.
Tests are defined in the
hello-world/tests folder in this project. Use NPM to install the Mocha test framework and run unit tests.
aws-sam-middy-app$ cd hello-world hello-world$ npm install hello-world$ npm run test
To delete the sample application and the bucket that you created, use the AWS CLI.
aws-sam-middy-app$ aws cloudformation delete-stack --stack-name aws-sam-middy-app aws-sam-middy-app$ aws s3 rb s3://BUCKET_NAME
See the AWS SAM developer guide for an introduction to SAM specification, the SAM CLI, and serverless application concepts.
Next, you can use AWS Serverless Application Repository to deploy ready to use Apps that go beyond hello world samples and learn how authors developed their applications: AWS Serverless Application Repository main page