OpenStackDeployment admission controller¶
CustomResourceDefinition resource in Kubernetes uses the
OpenAPI Specification version 2 to specify the schema of the resource
defined. The Kubernetes API outright rejects the resources that do not
pass this schema validation.
The language of the schema, however, is not expressive enough to define a specific validation logic that may be needed for a given resource. For this purpose, Kubernetes enables the extension of its API with Dynamic Admission Control.
For the OpenStackDeployment (OsDpl) CR the
is a natural choice. It is deployed as part of OpenStack Controller
by default and performs specific extended validations when an OsDpl CR is
created or updated.
The inexhaustive list of additional validations includes:
Deny the OpenStack version downgrade
Deny the OpenStack version skip-level upgrade
Deny the OpenStack master version deployment
Deny upgrade to the OpenStack master version
Deny upgrade if any part of an OsDpl CR specification changes along with the OpenStack version
Under specific circumstances, it may be viable to disable the admission controller, for example, when you attempt to deploy or upgrade to the master version of OpenStack.
Mirantis does not support MOS deployments performed without the OpenStackDeployment admission controller enabled. Disabling of the OpenStackDeployment admission controller is only allowed in staging non-production environments.
To disable the admission controller, ensure that the following structures and
values are present in the
openstack-controller HelmBundle resource:
apiVersion: lcm.mirantis.com/v1alpha1 kind: HelmBundle metadata: name: openstack-operator namespace: osh-system spec: releases: - name: openstack-operator values: admission: enabled: false
At that point, all safeguards except for those expressed by the CR definition are disabled.