crontab-crd.yaml

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: crontabs.stable.example.com
spec:
  group: stable.example.com
  versions:
    - name: v1
      served: true
      storage: true
  scope: Namespaced
  names:
    plural: crontabs
    singular: crontab
    kind: CronTab
    shortNames:
    - ct
  validation:
    openAPIV3Schema:
      type: object
      properties:
        spec:
          type: object
          properties:
            cronSpec:
              type: string
            image:
              type: string
            replicas:
              type: integer

crontab-crd2.yaml

  apiVersion: apiextensions.k8s.io/v1beta1
  kind: CustomResourceDefinition
  metadata:
    name: crontabs.stable.example.com
  spec:
    group: stable.example.com
    versions:
      - name: v1
        served: true
        storage: true
    scope: Namespaced
    names:
      plural: crontabs
      singular: crontab
      kind: CronTab
      shortNames:
      - ct
    additionalPrinterColumns:
    - name: Spec
      type: string
      description: The cron spec defining the interval a CronJob is run
      JSONPath: .spec.cronSpec
    - name: Replicas
      type: integer
      description: The number of jobs launched by the CronJob
      JSONPath: .spec.replicas
    - name: Age
      type: date
      JSONPath: .metadata.creationTimestamp

crontab-resource.yaml

apiVersion: "stable.example.com/v1"
kind: CronTab
metadata:
  name: my-new-cron-object
spec:
  cronSpec: "* * * * */5"
  image: my-awesome-cron-image

deployment.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: kuard
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: kuard
    spec:
      containers:
      - image: gcr.io/kuar-demo/kuard-amd64:1
        imagePullPolicy: Always
        name: kuard
        ports:
        - containerPort: 8080
        livenessProbe:
          httpGet:
            path: /healthy
            port: 8080
          initialDelaySeconds: 3
          periodSeconds: 3    
        readinessProbe:
          httpGet:
            path: /ready
            port: 8080
          initialDelaySeconds: 3
          periodSeconds: 3    

---
apiVersion: v1
kind: Service
metadata:
  name: kuard-service
spec:
  selector:
    app: kuard
  ports:
  - port: 80
    targetPort: 8080