class BucketPolicy (construct)

Language	Type name
.NET	Amazon.CDK.AWS.S3.BucketPolicy
Go	github.com/aws/aws-cdk-go/awscdk/v2/awss3#BucketPolicy
Java	software.amazon.awscdk.services.s3.BucketPolicy
Python	aws_cdk.aws_s3.BucketPolicy
TypeScript (source)	aws-cdk-lib » aws_s3 » BucketPolicy

Implements IConstruct, IDependable, IResource

The bucket policy for an Amazon S3 bucket.

Policies define the operations that are allowed on this resource.

You almost never need to define this construct directly.

All AWS resources that support resource policies have a method called addToResourcePolicy(), which will automatically create a new resource policy if one doesn't exist yet, otherwise it will add to the existing policy.

The bucket policy method is implemented differently than addToResourcePolicy() as BucketPolicy() creates a new policy without knowing one earlier existed. e.g. if during Bucket creation, if autoDeleteObject:true, these policies are added to the bucket policy: ["s3:DeleteObject", "s3:GetBucket", "s3:List*", "s3:PutBucketPolicy"], and when you add a new BucketPolicy with ["s3:GetObject", "s3:ListBucket"] on this existing bucket, invoking BucketPolicy() will create a new Policy without knowing one earlier exists already, so it creates a new one. In this case, the custom resource handler will not have access to s3:GetBucketTagging action which will cause failure during deletion of stack.

Hence its strongly recommended to use addToResourcePolicy() method to add new permissions to existing policy.

Example

const bucketName = "amzn-s3-demo-bucket";
const accessLogsBucket = new s3.Bucket(this, 'AccessLogsBucket', {
  objectOwnership: s3.ObjectOwnership.BUCKET_OWNER_ENFORCED,
  bucketName,
});

const bucketPolicy = new s3.CfnBucketPolicy(this, "BucketPolicy", {
  bucket: bucketName,
  policyDocument: {
    Statement: [
      {
        Action: 's3:*',
        Effect: 'Deny',
        Principal: {
          AWS: '*',
        },
        Resource: [
          accessLogsBucket.bucketArn,
          `${accessLogsBucket.bucketArn}/*`
        ],
      },
    ],
    Version: '2012-10-17',
  },
});

// Wrap L1 Construct with L2 Bucket Policy Construct. Subsequent
// generated bucket policy to allow access log delivery would append
// to the current policy.
s3.BucketPolicy.fromCfnBucketPolicy(bucketPolicy);

const bucket = new s3.Bucket(this, 'MyBucket', {
  serverAccessLogsBucket: accessLogsBucket,
  serverAccessLogsPrefix: 'logs',
});

Initializer

new BucketPolicy(scope: Construct, id: string, props: BucketPolicyProps)

Parameters

• scope Construct
• id string
• props BucketPolicyProps

Construct Props

Name	Type	Description
bucket	IBucket	The Amazon S3 bucket that the policy applies to.
removalPolicy?	RemovalPolicy	Policy to apply when the policy is removed from this stack.

---

bucket

Type: IBucket

The Amazon S3 bucket that the policy applies to.

---

removalPolicy?

Type: RemovalPolicy (optional, default: RemovalPolicy.DESTROY.)

Policy to apply when the policy is removed from this stack.

Properties

Name	Type	Description
bucket	IBucket	The Bucket this Policy applies to.
document	PolicyDocument	A policy document containing permissions to add to the specified bucket.
env	ResourceEnvironment	The environment this resource belongs to.
node	Node	The tree node.
stack	Stack	The stack in which this resource is defined.

---

bucket

Type: IBucket

The Bucket this Policy applies to.

---

document

Type: PolicyDocument

A policy document containing permissions to add to the specified bucket.

For more information, see Access Policy Language Overview in the Amazon Simple Storage Service Developer Guide.

---

env

Type: ResourceEnvironment

The environment this resource belongs to.

For resources that are created and managed by the CDK (generally, those created by creating new class instances like Role, Bucket, etc.), this is always the same as the environment of the stack they belong to; however, for imported resources (those obtained from static methods like fromRoleArn, fromBucketName, etc.), that might be different than the stack they were imported into.

---

node

Type: Node

The tree node.

---

stack

Type: Stack

The stack in which this resource is defined.

Methods

Name	Description
applyRemovalPolicy(removalPolicy)	Sets the removal policy for the BucketPolicy.
toString()	Returns a string representation of this construct.
static fromCfnBucketPolicy(cfnBucketPolicy)	Create a mutable BucketPolicy from a CfnBucketPolicy.

---

applyRemovalPolicy(removalPolicy)

public applyRemovalPolicy(removalPolicy: RemovalPolicy): void

Parameters

• removalPolicy RemovalPolicy — the RemovalPolicy to set.

Sets the removal policy for the BucketPolicy.

---

toString()

public toString(): string

Returns

• string

Returns a string representation of this construct.

---

static fromCfnBucketPolicy(cfnBucketPolicy)

public static fromCfnBucketPolicy(cfnBucketPolicy: CfnBucketPolicy): BucketPolicy

Parameters

• cfnBucketPolicy CfnBucketPolicy

Returns

• BucketPolicy

Create a mutable BucketPolicy from a CfnBucketPolicy.