Managing Policies

Managing Policies

A policy type can be treated as the meta-type of a Policy object. A registry of policy types is built when the Cluster service starts. When creating a Policy object, you will indicate the policy type used in its spec property.

List Policies

To examine the list of policies:

def list_policies(conn):
    print("List Policies:")

    for policy in conn.cluster.policies():

    for policy in conn.cluster.policies(sort='name:asc'):

When listing policies, you can specify the sorting option using the sort parameter and you can do pagination using the limit and marker parameters.

Full example: manage policy

Create Policy

When creating a policy, you will provide a dictionary with keys and values according to the policy type referenced.

def create_policy(conn):
    print("Create Policy:")

    spec = {
        'policy': 'senlin.policy.deletion',
        'version': 1.0,
        'properties': {
            'criteria': 'oldest_first',
            'destroy_after_deletion': True,

    policy = conn.cluster.create_policy('dp01', spec)

Optionally, you can specify a metadata keyword argument that contains some key-value pairs to be associated with the policy.

Full example: manage policy

Find Policy

To find a policy based on its name or ID:

def find_policy(conn):
    print("Find Policy:")

    policy = conn.cluster.find_policy('dp01')

Full example: manage policy

Get Policy

To get a policy based on its name or ID:

def get_policy(conn):
    print("Get Policy:")

    policy = conn.cluster.get_policy('dp01')

Full example: manage policy

Update Policy

After a policy is created, most of its properties are immutable. Still, you can update a policy’s name and/or metadata.

def update_policy(conn):
    print("Update Policy:")

    policy = conn.cluster.update_policy('dp01', name='dp02')

The Cluster service doesn’t allow updating the spec of a policy. The only way to achieve that is to create a new policy.

Full example: manage policy

Delete Policy

A policy can be deleted after creation, provided that it is not referenced by any active clusters or nodes. If you attempt to delete a policy that is still in use, you will get an error message.

def delete_policy(conn):
    print("Delete Policy:")


    print("Policy deleted.")
Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.