aws-cdk.aws-s3 1.2.0

CDK Constructs for AWS S3

Amazon S3 Construct Library

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Define an unencrypted S3 bucket.

new Bucket(this, 'MyFirstBucket');

Bucket constructs expose the following deploy-time attributes:

• bucketArn - the ARN of the bucket (i.e. arn:aws:s3:::bucket_name)
• bucketName - the name of the bucket (i.e. bucket_name)
• bucketWebsiteUrl - the Website URL of the bucket (i.e. http://bucket_name.s3-website-us-west-1.amazonaws.com)
• bucketDomainName - the URL of the bucket (i.e. bucket_name.s3.amazonaws.com)
• bucketDualStackDomainName - the dual-stack URL of the bucket (i.e. bucket_name.s3.dualstack.eu-west-1.amazonaws.com)
• bucketRegionalDomainName - the regional URL of the bucket (i.e. bucket_name.s3.eu-west-1.amazonaws.com)
• arnForObjects(pattern) - the ARN of an object or objects within the bucket (i.e. arn:aws:s3:::bucket_name/exampleobject.png or arn:aws:s3:::bucket_name/Development/*)
• urlForObject(key) - the URL of an object within the bucket (i.e. https://s3.cn-north-1.amazonaws.com.cn/china-bucket/mykey)

Encryption

Define a KMS-encrypted bucket:

const bucket = new Bucket(this, 'MyUnencryptedBucket', {
    encryption: BucketEncryption.KMS
});

// you can access the encryption key:
assert(bucket.encryptionKey instanceof kms.Key);

You can also supply your own key:

const myKmsKey = new kms.Key(this, 'MyKey');

const bucket = new Bucket(this, 'MyEncryptedBucket', {
    encryption: BucketEncryption.KMS,
    encryptionKey: myKmsKey
});

assert(bucket.encryptionKey === myKmsKey);

Use BucketEncryption.ManagedKms to use the S3 master KMS key:

const bucket = new Bucket(this, 'Buck', {
    encryption: BucketEncryption.KMS_MANAGED
});

assert(bucket.encryptionKey == null);

Permissions

A bucket policy will be automatically created for the bucket upon the first call to addToResourcePolicy(statement):

const bucket = new Bucket(this, 'MyBucket');
bucket.addToResourcePolicy(new iam.PolicyStatement({
  actions: ['s3:GetObject'],
  resources: [bucket.arnForObjects('file.txt')],
  principals: [new iam.AccountRootPrincipal()],
}));

Most of the time, you won't have to manipulate the bucket policy directly. Instead, buckets have "grant" methods called to give prepackaged sets of permissions to other resources. For example:

const lambda = new lambda.Function(this, 'Lambda', { /* ... */ });

const bucket = new Bucket(this, 'MyBucket');
bucket.grantReadWrite(lambda);

Will give the Lambda's execution role permissions to read and write from the bucket.

Sharing buckets between stacks

To use a bucket in a different stack in the same CDK application, pass the object to the other stack:

/**
 * Stack that defines the bucket
 */
class Producer extends cdk.Stack {
    public readonly myBucket: s3.Bucket;

    constructor(scope: cdk.App, id: string, props?: cdk.StackProps) {
        super(scope, id, props);

        const bucket = new s3.Bucket(this, 'MyBucket', {
          removalPolicy: cdk.RemovalPolicy.DESTROY
        });
        this.myBucket = bucket;
    }
}

interface ConsumerProps extends cdk.StackProps {
    userBucket: s3.IBucket;
}

/**
 * Stack that consumes the bucket
 */
class Consumer extends cdk.Stack {
    constructor(scope: cdk.App, id: string, props: ConsumerProps) {
        super(scope, id, props);

        const user = new iam.User(this, 'MyUser');
        props.userBucket.grantReadWrite(user);
    }
}

const producer = new Producer(app, 'ProducerStack');
new Consumer(app, 'ConsumerStack', { userBucket: producer.myBucket });

Importing existing buckets

To import an existing bucket into your CDK application, use the Bucket.fromBucketAttributes factory method. This method accepts BucketAttributes which describes the properties of an already existing bucket:

const bucket = Bucket.fromBucketAttributes(this, 'ImportedBucket', {
    bucketArn: 'arn:aws:s3:::my-bucket'
});

// now you can just call methods on the bucket
bucket.grantReadWrite(user);

Alternatively, short-hand factories are available as Bucket.fromBucketName and Bucket.fromBucketArn, which will derive all bucket attributes from the bucket name or ARN respectively:

const byName = Bucket.fromBucketName(this, 'BucketByName', 'my-bucket');
const byArn  = Bucket.fromBucketArn(this, 'BucketByArn', 'arn:aws:s3:::my-bucket');

Bucket Notifications

The Amazon S3 notification feature enables you to receive notifications when certain events happen in your bucket as described under S3 Bucket Notifications of the S3 Developer Guide.

To subscribe for bucket notifications, use the bucket.addEventNotification method. The bucket.addObjectCreatedNotification and bucket.addObjectRemovedNotification can also be used for these common use cases.

The following example will subscribe an SNS topic to be notified of all s3:ObjectCreated:* events:

import s3n = require('@aws-cdk/aws-s3-notifications');

const myTopic = new sns.Topic(this, 'MyTopic');
bucket.addEventNotification(s3.EventType.OBJECT_CREATED, new s3n.SnsDestination(topic));

This call will also ensure that the topic policy can accept notifications for this specific bucket.

Supported S3 notification targets are exposed by the @aws-cdk/aws-s3-notifications package.

It is also possible to specify S3 object key filters when subscribing. The following example will notify myQueue when objects prefixed with foo/ and have the .jpg suffix are removed from the bucket.

bucket.addEventNotification(s3.EventType.OBJECT_REMOVED,
  new s3n.SqsDestination(myQueue),
  { prefix: 'foo/', suffix: '.jpg' });

Block Public Access

Use blockPublicAccess to specify block public access settings on the bucket.

Enable all block public access settings:

const bucket = new Bucket(this, 'MyBlockedBucket', {
    blockPublicAccess: BlockPublicAccess.BLOCK_ALL
});

Block and ignore public ACLs:

const bucket = new Bucket(this, 'MyBlockedBucket', {
    blockPublicAccess: BlockPublicAccess.BLOCK_ACLS
});

Alternatively, specify the settings manually:

const bucket = new Bucket(this, 'MyBlockedBucket', {
    blockPublicAccess: new BlockPublicAccess({ blockPublicPolicy: true })
});

When blockPublicPolicy is set to true, grantPublicRead() throws an error.