BucketPolicy

class aws_cdk.aws_s3.BucketPolicy(scope, id, *, bucket, removal_policy=None)

Bases: Resource

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.

ExampleMetadata:: infused

Example:

bucket_name = "amzn-s3-demo-bucket"
access_logs_bucket = s3.Bucket(self, "AccessLogsBucket",
    object_ownership=s3.ObjectOwnership.BUCKET_OWNER_ENFORCED,
    bucket_name=bucket_name
)

bucket_policy = s3.CfnBucketPolicy(self, "BucketPolicy",
    bucket=bucket_name,
    policy_document={
        "Statement": [{
            "Action": "s3:*",
            "Effect": "Deny",
            "Principal": {
                "AWS": "*"
            },
            "Resource": [access_logs_bucket.bucket_arn, f"{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.from_cfn_bucket_policy(bucket_policy)

bucket = s3.Bucket(self, "MyBucket",
    server_access_logs_bucket=access_logs_bucket,
    server_access_logs_prefix="logs"
)

Parameters:

scope (Construct) –
id (str) –
bucket (IBucket) – The Amazon S3 bucket that the policy applies to.
removal_policy (Optional[RemovalPolicy]) – Policy to apply when the policy is removed from this stack. Default: - RemovalPolicy.DESTROY.

Methods

apply_removal_policy(removal_policy)

Sets the removal policy for the BucketPolicy.

Parameters:: removal_policy (RemovalPolicy) – the RemovalPolicy to set.
Return type:: None

to_string()

Returns a string representation of this construct.

Return type:: str

Attributes

bucket: The Bucket this Policy applies to.

document

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

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: The tree node.

stack: The stack in which this resource is defined.

Static Methods

classmethod from_cfn_bucket_policy(cfn_bucket_policy)

Create a mutable BucketPolicy from a CfnBucketPolicy.

Parameters:

cfn_bucket_policy (CfnBucketPolicy) –

Return type:

BucketPolicy

classmethod is_construct(x)

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters:: x (Any) – Any object.
Return type:: bool
Returns:: true if x is an object created from a class which extends Construct.

classmethod is_owned_resource(construct)

Returns true if the construct was created by CDK, and false otherwise.

Parameters:

construct (IConstruct) –

Return type:

bool

classmethod is_resource(construct)

Check whether the given construct is a Resource.

Parameters:

construct (IConstruct) –

Return type:

bool