Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Using sam init

The Amazon Serverless Application Model Command Line Interface (Amazon SAM CLI) sam init command provides options to initialize a new serverless application that consists of:

For an introduction to the Amazon SAM CLI, see What is the Amazon SAM CLI?.

For a list of Amazon SAM CLI sam init command options, see sam init.

Initialize a new serverless application

Choose a starting template

A template consists of the following:

You can select from a list of available Amazon Quick Start Templates or provide your own Custom Template Location.

Choose a runtime

When you choose an Amazon Quick Start Template, the Amazon SAM CLI prompts you to select a runtime for your Lambda functions. The list of options displayed by the Amazon SAM CLI are the runtimes supported natively by Lambda.

You can use any other programming language with a custom runtime. To do this, you need to manually create your starting application structure. You can then use sam init to quickly initialize your application by configuring a custom template location.

From your selection, the Amazon SAM CLI creates the starting directory for your Lambda function code and dependencies.

If Lambda supports multiple dependency managers for your runtime, you will be prompted to choose your preferred dependency manager.

Choose a package type

When you choose an Amazon Quick Start Template and a runtime, the Amazon SAM CLI prompts you to select a package type. The package type determines how your Lambda functions are deployed to use with the Lambda service. The two supported package types are:

To learn more about deployment package types, see Lambda deployment packages in the Amazon Lambda Developer Guide.

The following is an example directory structure of an application with a Lambda function packaged as a container image. The Amazon SAM CLI downloads the image and creates a Dockerfile in the function's directory to specify the image.

sam-app
├── README.md
├── __init__.py
├── events
│   └── event.json
├── hello_world
│   ├── Dockerfile
│   ├── __init__.py
│   ├── app.py
│   └── requirements.txt
├── samconfig.toml
├── template.yaml
└── tests
    ├── __init__.py
    └── unit
        ├── __init__.py
        └── test_handler.py

The following is an example directory structure of an application with a function packaged as a .zip file archive.

sam-app
├── README.md
├── __init__.py
├── events
│   └── event.json
├── hello_world
│   ├── __init__.py
│   ├── app.py
│   └── requirements.txt
├── samconfig.toml
├── template.yaml
└── tests
    ├── __init__.py
    ├── integration
    │   ├── __init__.py
    │   └── test_api_gateway.py
    ├── requirements.txt
    └── unit
        ├── __init__.py
        └── test_handler.py

Configure Amazon X-Ray tracing

You can choose to activate Amazon X-Ray tracing. To learn more, see What is Amazon X-Ray? in the Amazon X-Ray Developer Guide.

If you activate, the Amazon SAM CLI configures your Amazon SAM template. The following is an example:

Globals:
  Function:
    ...
    Tracing: Active
  Api:
    TracingEnabled: True

Configure monitoring with Amazon CloudWatch Application Insights

You can choose to activate monitoring using Amazon CloudWatch Application Insights. To learn more, see Amazon CloudWatch Application Insights in the Amazon CloudWatch User Guide.

If you activate, the Amazon SAM CLI configures your Amazon SAM template. The following is an example:

Resources:
  ApplicationResourceGroup:
    Type: AWS::ResourceGroups::Group
    Properties:
      Name:
        Fn::Join:
        - ''
        - - ApplicationInsights-SAM-
          - Ref: AWS::StackName
      ResourceQuery:
        Type: CLOUDFORMATION_STACK_1_0
  ApplicationInsightsMonitoring:
    Type: AWS::ApplicationInsights::Application
    Properties:
      ResourceGroupName:
        Fn::Join:
        - ''
        - - ApplicationInsights-SAM-
          - Ref: AWS::StackName
      AutoConfigurationEnabled: 'true'
    DependsOn: ApplicationResourceGroup

Name your application

Provide a name for your application. The Amazon SAM CLI creates a top-level folder for your application using this name.

Options for sam init

The following are some of the main options you can use with the sam init command. For a list of all options, see sam init.

Initialize an application using a custom template location

Use the --location option and provide a supported custom template location. The following is an example:

$ sam init --location https://github.com/aws-samples/sessions-with-aws-sam/raw/master/starter-templates/web-app.zip

Initialize an application without the interactive flow

Use the --no-interactive option and provide your configuration choices at the command line to skip the interactive flow. The following is an example:

$ sam init --no-interactive --runtime go1.x --name go-demo --dependency-manager mod --app-template hello-world

Troubleshooting

To troubleshoot the Amazon SAM CLI, see Amazon SAM CLI troubleshooting.

Examples

Initialize a new serverless application using the Hello World Amazon Starter Template

For this example, see Step 1: Initialize the sample Hello World application in Tutorial: Deploying a Hello World application.

Initialize a new serverless application with a custom template location

The following are examples of providing a GitHub location to your custom template:

$ sam init --location gh:aws-samples/cookiecutter-aws-sam-python
$ sam init --location git+sh://git@github.com/aws-samples/cookiecutter-aws-sam-python.git
$ sam init --location hg+ssh://hg@bitbucket.org/repo/template-name

The following is an example of a local file path:

$ sam init --location /path/to/template.zip

The following is an example of a path reachable by HTTPS:

$ sam init --location https://github.com/aws-samples/sessions-with-aws-sam/raw/master/starter-templates/web-app.zip

Learn more

To learn more about using the sam init command, see the following: