namespaced_custom_object.py

# Copyright 2019 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Uses a Custom Resource Definition (CRD) to create a custom object, in this case
a CronTab. This example use an example CRD from this tutorial:
https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/

The following yaml manifest has to be applied first for namespaced scoped CRD:

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: crontabs.stable.example.com
spec:
  group: stable.example.com
  versions:
    - name: v1
      served: true
      storage: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                cronSpec:
                  type: string
                image:
                  type: string
                replicas:
                  type: integer
  scope: Namespaced
  names:
    plural: crontabs
    singular: crontab
    kind: CronTab
    shortNames:
    - ct
"""

from pprint import pprint

from kubernetes import client, config


def main():
    config.load_kube_config()

    api = client.CustomObjectsApi()

    # it's my custom resource defined as Dict
    my_resource = {
        "apiVersion": "stable.example.com/v1",
        "kind": "CronTab",
        "metadata": {"name": "my-new-cron-object"},
        "spec": {
            "cronSpec": "* * * * */5",
            "image": "my-awesome-cron-image"
        }
    }

    # patch to update the `spec.cronSpec` field
    patch_body = {
        "spec": {"cronSpec": "* * * * */10", "image": "my-awesome-cron-image"}
    }

    # create the resource
    api.create_namespaced_custom_object(
        group="stable.example.com",
        version="v1",
        namespace="default",
        plural="crontabs",
        body=my_resource,
    )
    print("Resource created")

    # get the resource and print out data
    resource = api.get_namespaced_custom_object(
        group="stable.example.com",
        version="v1",
        name="my-new-cron-object",
        namespace="default",
        plural="crontabs",
    )
    print("Resource details:")
    pprint(resource)

    # patch the namespaced custom object to update the `spec.cronSpec` field
    patch_resource = api.patch_namespaced_custom_object(
        group="stable.example.com",
        version="v1",
        name="my-new-cron-object",
        namespace="default",
        plural="crontabs",
        body=patch_body,
    )
    print("Resource details:")
    pprint(patch_resource)

    # delete it
    api.delete_namespaced_custom_object(
        group="stable.example.com",
        version="v1",
        name="my-new-cron-object",
        namespace="default",
        plural="crontabs",
        body=client.V1DeleteOptions(),
    )
    print("Resource deleted")


if __name__ == "__main__":
    main()