@aws-cdk/aws-s3objectlambda-alpha/README.md

The CDK Construct Library for AWS::S3ObjectLambda

# AWS::S3ObjectLambda Construct Library
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---

![cdk-constructs: Experimental](https://img.shields.io/badge/cdk--constructs-experimental-important.svg?style=for-the-badge)

> The APIs of higher level constructs in this module are experimental and under active development.
> They are subject to non-backward compatible changes or removal in any future version. These are
> not subject to the [Semantic Versioning](https://semver.org/) model and breaking changes will be
> announced in the release notes. This means that while you may use them, you may need to update
> your source code when upgrading to a newer version of this package.

---

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This construct library allows you to define S3 object lambda access points.

```ts
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as s3objectlambda from '@aws-cdk/aws-s3objectlambda-alpha';
import * as cdk from 'aws-cdk-lib';

const stack = new cdk.Stack();
const bucket = new s3.Bucket(stack, 'MyBucket');
const handler = new lambda.Function(stack, 'MyFunction', {
	runtime: lambda.Runtime.NODEJS_LATEST,
	handler: 'index.handler',
	code: lambda.Code.fromAsset('lambda.zip'),
});
new s3objectlambda.AccessPoint(stack, 'MyObjectLambda', {
	bucket,
	handler,
	accessPointName: 'my-access-point',
	payload: {
		prop: "value",
	},
});
```

## Handling range and part number requests

Lambdas are currently limited to only transforming `GetObject` requests. However, they can additionally support `GetObject-Range` and `GetObject-PartNumber` requests, which needs to be specified in the access point configuration:

```ts
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as s3objectlambda from '@aws-cdk/aws-s3objectlambda-alpha';
import * as cdk from 'aws-cdk-lib';

const stack = new cdk.Stack();
const bucket = new s3.Bucket(stack, 'MyBucket');
const handler = new lambda.Function(stack, 'MyFunction', {
	runtime: lambda.Runtime.NODEJS_LATEST,
	handler: 'index.handler',
	code: lambda.Code.fromAsset('lambda.zip'),
});
new s3objectlambda.AccessPoint(stack, 'MyObjectLambda', {
	bucket,
	handler,
	accessPointName: 'my-access-point',
	supportsGetObjectRange: true,
	supportsGetObjectPartNumber: true,
});
```

## Pass additional data to Lambda function

You can specify an additional object that provides supplemental data to the Lambda function used to transform objects. The data is delivered as a JSON payload to the Lambda:

```ts
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as s3objectlambda from '@aws-cdk/aws-s3objectlambda-alpha';
import * as cdk from 'aws-cdk-lib';

const stack = new cdk.Stack();
const bucket = new s3.Bucket(stack, 'MyBucket');
const handler = new lambda.Function(stack, 'MyFunction', {
	runtime: lambda.Runtime.NODEJS_LATEST,
	handler: 'index.handler',
	code: lambda.Code.fromAsset('lambda.zip'),
});
new s3objectlambda.AccessPoint(stack, 'MyObjectLambda', {
	bucket,
	handler,
	accessPointName: 'my-access-point',
	payload: {
		prop: "value",
	},
});
```

## Accessing the S3 AccessPoint ARN

If you need access to the s3 accesspoint, you can get its ARN like so:

```ts
import * as s3objectlambda from '@aws-cdk/aws-s3objectlambda-alpha';

declare const accessPoint: s3objectlambda.AccessPoint;
const s3AccessPointArn = accessPoint.s3AccessPointArn;
```

This is only supported for AccessPoints created in the stack - currently you're unable to get the S3 AccessPoint ARN for imported AccessPoints. To do that you'd have to know the S3 bucket name beforehand.