CRD helloworld

Reference official

https://kubernetes.io/zh/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/

This example is the simplest HelloWorld example. It does not involve coding content, but can be used to understand how CRD works

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  # The name must match the spec field below, and the format is' < plural form of name >< Group name > '
  name: crontabs.stable.example.com
spec:
  # Group name for rest API: / APIs / < group > / < version >
  group: stable.example.com
  # List the supported versions of this customresourcedefinition
  versions:
    - name: v1
      # Each version can be enabled or disabled independently through the served flag
      served: true
      # One and only one version must be marked as a stored version
      storage: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                cronSpec:
                  type: string
                image:
                  type: string
                replicas:
                  type: integer
  # It can be named or cluster
  scope: Namespaced
  names:
    # Plural of name for URL: / APIs / < group > / < version > / < plural of name >
    plural: crontabs
    # The singular form of the name as an alias when used on the command line and when displayed
    singular: crontab
    # Kind is usually a singular form of camel cased. Your resource list will use this form.
    kind: CronTab
    # Shortnames allows you to match resources with shorter strings on the command line
    shortNames:
    - ct

After the above steps, we will get a new service endpoint in

/apis/stable.example.com/v1/namespaces/*/crontabs/...

Create crontab custom object

my-crontab.yaml

apiVersion: "stable.example.com/v1"
kind: CronTab
metadata:
  name: my-new-cron-object
spec:
  cronSpec: "*/60 * * * *"
  image: my-awesome-cron-image