Publishing serverless applications using the AWS SAM CLI - AWS Serverless Application Model
PrerequisitesPublishing a new applicationPublishing a new version of an existing applicationAdditional topics

Publishing serverless applications using the AWS SAM CLI

To make your AWS SAM application available for others to find and deploy, you can use the AWS SAM CLI to publish it to the AWS Serverless Application Repository. To publish your application using the AWS SAM CLI, you must define it using an AWS SAM template. You also must have tested it locally or in the AWS Cloud.

Follow the instructions in this topic to create a new application, create a new version of an existing application, or update the metadata of an existing application. (What you do depends on whether the application already exists in the AWS Serverless Application Repository, and whether any application metadata is changing.) For more information about application metadata, see AWS SAM template Metadata section properties.

Prerequisites

Before you publish an application to the AWS Serverless Application Repository using the AWS SAM CLI, you must have the following:

  • The AWS SAM CLI installed. For more information, see Installing the AWS SAM CLI. To determine whether the AWS SAM CLI is installed, run the following command: 

    sam --version

  • A valid AWS SAM template.

  • Your application code and dependencies that the AWS SAM template references.

  • A semantic version, required only to share your application publicly. This value can be as simple as 1.0.

  • A URL that points to your application's source code.

  • A README.md file. This file should describe how customers can use your application and how to configure it before deploying it in their own AWS accounts.

  • A LICENSE.txt file, required only to share your application publicly.

  • If your application contains any nested applications, you must have already published them to the AWS Serverless Application Repository.

  • A valid Amazon Simple Storage Service (Amazon S3) bucket policy that grants the service read permissions for artifacts that you upload to Amazon S3 when you package your application. To set up this policy, do the following:

    1. Open the Amazon S3 console at https://console.aws.amazon.com/s3/.

    2. Choose the name of the Amazon S3 bucket that you used to package your application.

    3. Choose Permissions.

    4. On the Permissions tab, under Bucket policy, choose Edit.

    5. On the Edit bucket policy page, paste the following policy statement into the Policy editor. In the policy statement, make sure to use your bucket name in the Resource element and your AWS account ID in the Condition element. The expression in the Condition element ensures that AWS Serverless Application Repository has permission to access only applications from the specified AWS account. For more information about policy statements, see IAM JSON policy elements reference in the IAM User Guide. 

      {
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service":  "serverlessrepo.amazonaws.com"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::<your-bucket-name>/*",
            "Condition" : {
                "StringEquals": {
                    "aws:SourceAccount": "123456789012"
                }
            }
        }
    ]
}

    6. Choose Save changes.

Publishing a new application

Step 1: Add a Metadata section to the AWS SAM template

First, add a Metadata section to your AWS SAM template. Provide the application information to be published to the AWS Serverless Application Repository.

The following is an example Metadata section: 

Metadata:
  AWS::ServerlessRepo::Application:
    Name: my-app
    Description: hello world
    Author: user1
    SpdxLicenseId: Apache-2.0
    LicenseUrl: LICENSE.txt
    ReadmeUrl: README.md
    Labels: ['tests']
    HomePageUrl: https://github.com/user1/my-app-project
    SemanticVersion: 0.0.1
    SourceCodeUrl: https://github.com/user1/my-app-project

Resources:
  HelloWorldFunction:
    Type: AWS::Lambda::Function
      Properties:
        ...
        CodeUri: source-code1
        ...

For more information about the Metadata section of the AWS SAM template, see AWS SAM template Metadata section properties.

Step 2: Package the application

Run the following AWS SAM CLI command, which uploads the application's artifacts to Amazon S3 and outputs a new template file called packaged.yaml: 

sam package --template-file template.yaml --output-template-file packaged.yaml --s3-bucket <your-bucket-name>

You use the packaged.yaml template file in the next step to publish the application to the AWS Serverless Application Repository. This file is similar to the original template file (template.yaml), but it has a key difference—the CodeUri, LicenseUrl, and ReadmeUrl properties point to the Amazon S3 bucket and objects that contain the respective artifacts.

The following snippet from an example packaged.yaml template file shows the CodeUri property: 

MySampleFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: s3://bucketname/fbd77a3647a4f47a352fcObjectGUID

...

Step 3: Publish the application

To publish a private version of your AWS SAM application to the AWS Serverless Application Repository, run the following AWS SAM CLI command: 

sam publish --template packaged.yaml --region us-east-1

The output of the sam publish command includes a link to your application on the AWS Serverless Application Repository. You can also go directly to the AWS Serverless Application Repository landing page and search for your application.

Step 4: Share the application (optional)

By default, your application is set to private, so it isn't visible to other AWS accounts. To share your application with others, you must either make it public or grant permission to a specific list of AWS accounts.

For information about sharing your application using the AWS CLI, see AWS Serverless Application Repository Resource-Based Policy Examples in the AWS Serverless Application Repository Developer Guide. For information on sharing your application using the AWS Management Console, see Sharing an Application in the AWS Serverless Application Repository Developer Guide.

Publishing a new version of an existing application

After you've published an application to the AWS Serverless Application Repository, you might want to publish a new version of it. For example, you might have changed your Lambda function code or added a new component to your application architecture.

To update an application that you've previously published, publish the application again using the same process detailed previously. In the Metadata section of the AWS SAM template file, provide the same application name that you originally published it with, but include a new SemanticVersion value.

For example, consider an application published with the name SampleApp and a SemanticVersion of 1.0.0. To update that application, the AWS SAM template must have the application name SampleApp and a SemanticVersion of 1.0.1 (or anything other than 1.0.0).

Additional topics