Running in an AWS Lambda Function

The server can be deployed to run in an AWS Lambda. The following steps take you through creating:

• An S3 bucket to store the artifacts
• An IAM role to grant the Lambda permission to access the bucket
• The Lambda function
• A Lambda Function URL
• Configuring your repository to use the new API

Create an S3 Bucket to store artifacts

First, create an S3 Bucket with a unique name, such as turborepo-cache-udaw82. Leave Block all public access ticked to ensure your artifacts remain private.

Note: To prevent this bucket from growing forever, you may want to create a Lifecyle rule to expire cache objects that are older than a certain number of days.

Create an IAM role to grant the Lambda permission to access the bucket

Create a new IAM role. Under Trusted entity type choose AWS service, and under Use case select Lambda. On the Add permissions screen, click Next. On the Name, review, and create screen create a name for your role such as turborepo-cache-lambda-role then click on Create role.

View your new role, and under Permissions policies click the button Add permissions and choose Create inline policy. Click on JSON and add the following policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:*"
            ],
            "Resource": [
                "arn:aws:s3:::<your_bucket_name>",
                "arn:aws:s3:::<your_bucket_name>/*"
            ]
        }
    ]
}

This will only grant the Lambda function access to the artifacts bucket, and no other S3 resources.

Click on Review policy and give your policy a name such as turborepo-cache-lambda-policy, then click on Create Policy.

Create the Lambda Function

Create a new Lambda function with a name like turborepo-cache-lambda using the latest Node.js runtime. Under Permissions click on Change default execution role, select Use an existing role and select the role you just created. Click on Create function.

Handler code

Create a new package for your Lambda handler and add turborepo-remote-cache as a dependency. Your index.js handler code should look like this:

export { handler } from 'turborepo-remote-cache/aws-lambda';

Note - You will need to bundle dependencies and upload the handler code. How you choose to do this is outside the scope of this guide, but one method to consider is using esbuild:

esbuild src/index.js --bundle --platform=node --outfile=dist/index.js

Configuration

Under your Lambda Configuration, edit the General configuration and increase the timeout to 10 seconds (as the default value of 3 seconds can sometimes cause timeouts).

Go into Environment variables and create the following environment variables:

Variable	Value
STORAGE_PATH	your_bucket_name
STORAGE_PROVIDER	s3
TURBO_TOKEN	your_secret_key

See Environment variables for more information on configuring these.

Function URL

Under your Lambda Configuration, head to Function URL and click on Create function URL.

Select Auth type: NONE.

Open Additional settings and enable CORS with the following settings:

• Allow origin: *
• Allow headers: *
• Allow methods: *

Click on Save.

Copy the Function URL and use this to set up your repository.

Configuring your repository to use the new API

You will need to enable custom remote caching in your turbo repository. Your Invoke URL is your Turborepo API URL, see Enable custom remote caching in a Turborepo monorepo for more information on how to configure this.

Your remote turborepo-remote-cache API is now ready to use!