Amazon API Gateway REST API with S3 integration

The SAM template deploys an Amazon API Gateway REST API endpoint with a read-only S3 integration.

The API exposes 3 GET methods:

• Root GET method: it provides a list of the S3 buckets of the account where the stack is deployed.
• {folder} GET method: it provides a list of the objects contained in the bucket {folder}
• {item} GET method: it returns the contents of the object {item}.

The template also deploys an IAM role with S3 read-only capabilities that is used by API Gateway to integrate with S3.

Since this is API Gateway effectively acts as a proxy S3, every GET method is protected by IAM authentication to prevent public access.

Note: when deploying this pattern, CAPABILITY_IAM is required.

Learn more about this pattern at Serverless Land Patterns: https://serverlessland.com/patterns/apigw-s3-proxy

Important: this application uses various AWS services and there are costs associated with these services after the Free Tier usage - please see the AWS Pricing page for details. You are responsible for any AWS costs incurred. No warranty is implied in this example.

Requirements

• Create an AWS account if you do not already have one and log in. The IAM user that you use must have sufficient permissions to make necessary AWS service calls and manage AWS resources.
• AWS CLI installed and configured
• Git Installed
• AWS Serverless Application Model (AWS SAM) installed

Deployment Instructions

1. Create a new directory, navigate to that directory in a terminal and clone the GitHub repository:

   git clone https://github.com/aws-samples/serverless-patterns
   

2. Change directory to the pattern directory:

   cd apigw-s3-proxy
   

3. From the command line, use AWS SAM to deploy the AWS resources for the pattern as specified in the template.yml file:

   sam deploy -g
   

4. During the prompts:

   • Enter a stack name
   • Select the desired AWS Region
   • Allow SAM to create roles with the required permissions if needed.

   Once you have run guided mode once, you can use sam deploy in future to use these defaults.

5. Note the outputs from the SAM deployment process. These contain the resource names and/or ARNs which are used for testing.

Testing

The stack will output the api endpoint. Since all the methods are protected with IAM authentication, you can use Postman to send a SigV4-signed HTTP request to the API Gateway endpoint.

https://12345abcde.execute-api.{region}.amazonaws.com/Prod/mybucket/myobject.txt

Cleanup

1. Delete the stack

   sam delete
2. Confirm the stack has been deleted

   aws cloudformation list-stacks --query "StackSummaries[?contains(StackName,'STACK_NAME')].StackStatus"

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