RemovalPolicy

class aws_cdk.RemovalPolicy(*values)

Bases: Enum

Possible values for a resource’s Removal Policy.

The removal policy controls what happens to the resource if it stops being managed by CloudFormation. This can happen in one of three situations:

  • The resource is removed from the template, so CloudFormation stops managing it;

  • A change to the resource is made that requires it to be replaced, so CloudFormation stops managing it;

  • The stack is deleted, so CloudFormation stops managing all resources in it.

The Removal Policy applies to all above cases.

Many stateful resources in the AWS Construct Library will accept a removalPolicy as a property, typically defaulting it to RETAIN.

If the AWS Construct Library resource does not accept a removalPolicy argument, you can always configure it by using the escape hatch mechanism, as shown in the following example:

# bucket: s3.Bucket


cfn_bucket = bucket.node.find_child("Resource")
cfn_bucket.apply_removal_policy(RemovalPolicy.DESTROY)
ExampleMetadata:

fixture=default infused

Example:

bucket = s3.Bucket(self, "memoryBucket",
    bucket_name="test-memory",
    removal_policy=cdk.RemovalPolicy.DESTROY,
    auto_delete_objects=True
)

topic = sns.Topic(self, "topic")

# Create a custom semantic memory strategy
self_managed_strategy = agentcore.MemoryStrategy.using_self_managed(
    name="selfManagedStrategy",
    description="self managed memory strategy",
    historical_context_window_size=5,
    invocation_configuration=agentcore.InvocationConfiguration(
        topic=topic,
        s3_location=s3.Location(
            bucket_name=bucket.bucket_name,
            object_key="memory/"
        )
    ),
    trigger_conditions=agentcore.TriggerConditions(
        message_based_trigger=1,
        time_based_trigger=cdk.Duration.seconds(10),
        token_based_trigger=100
    )
)

# Create memory with custom strategy
memory = agentcore.Memory(self, "MyMemory",
    memory_name="my-custom-memory",
    description="Memory with custom strategy",
    expiration_duration=cdk.Duration.days(90),
    memory_strategies=[self_managed_strategy]
)

Attributes

DESTROY

When this removal policy is applied, the resource will be physically destroyed when it is removed from the stack or when the stack is deleted.

RETAIN

This uses the ‘Retain’ DeletionPolicy, which will cause the resource to be retained in the account, but orphaned from the stack.

Most resources default to this removal policy.

RETAIN_ON_UPDATE_OR_DELETE

Resource will be retained when they are requested to be deleted during a stack delete request or need to be replaced due to a stack update request.

Resource are not retained, if the creation is rolled back.

The result is that new, empty, and unused resources are deleted, while in-use resources and their data are retained.

This uses the ‘RetainExceptOnCreate’ DeletionPolicy, and the ‘Retain’ UpdateReplacePolicy, when applyToUpdateReplacePolicy is set.

See:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html#aws-attribute-deletionpolicy-options

SNAPSHOT

This retention policy deletes the resource, but saves a snapshot of its data before deleting, so that it can be re-created later.

Only available for some stateful resources, like databases, EC2 volumes, etc.

See:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html#aws-attribute-deletionpolicy-options