Elastic Container Instance:Manage ImageCaches

Make preparations

Log on to your Kubernetes cluster and run the following command to check whether the Kubernetes cluster supports ImageCaches:

kubectl get crd/imagecaches.eci.alibabacloud.com

• If an error is returned, the cluster does not support ImageCaches. Sample output:

  Error from server (NotFound): customresourcedefinitions.apiextensions.k8s.io "imagecaches.eci.alibabacloud.com" not found

  If your cluster does not support ImageCaches, update the ack-virtual-node component to a version that supports ImageCaches.

  Note

  We recommend that you update the ack-virtual-node component to the latest version to use new features.

  • For information about the versions of ack-virtual-node, see ack-virtual-node.

  • For information about how to update ack-virtual-node, see Manage system components.

• If information about imagecaches.eci.alibabacloud.com is returned, your Kubernetes cluster supports ImageCaches. Sample output:

  NAME                               CREATED AT
  imagecaches.eci.alibabacloud.com   2024-01-23T05:54:44Z

  If the ImageCache CRD in your cluster is not of the latest version, we recommend that you run the kubectl apply command to update the ImageCache CRD to the latest version.

  kubectl apply -f imagecache-crd-sample.yaml

  Unfold to view imagecache-crd-sample.yaml

  apiVersion: apiextensions.k8s.io/v1beta1
  kind: CustomResourceDefinition
  metadata:
    name: imagecaches.eci.alibabacloud.com
  spec:
    group: eci.alibabacloud.com
    version: v1
    names:
      kind: ImageCache
      plural: imagecaches
      shortNames:
      - ic
      categories:
      - all
    scope: Cluster
    subresources:
      status: {}
    validation:
      openAPIV3Schema:
        required:
        - spec
        properties:
          spec:
            type: object
            required:
            - images
            properties:
              imagePullSecrets:
                type: array
                items:
                  type: string
              images:
                minItems: 1
                type: array
                items:
                  type: string
              imageCacheSize:
                type: integer
              retentionDays:
                type: integer
    additionalPrinterColumns:
    - name: Age
      type: date
      JSONPath: .metadata.creationTimestamp
    - name: CacheId
      type: string
      JSONPath: .status.imageCacheId
    - name: Phase
      type: string
      JSONPath: .status.phase
    - name: Progress
      type: string
      JSONPath: .status.progress

Configure an ImageCache

The following code provides the YAML configuration file of an ImageCache. For more information, see Kubernetes ImageCache API.

apiVersion: eci.alibabacloud.com/v1
kind: ImageCache
metadata:
  name: imagecache-sample
  annotations:
    k8s.aliyun.com/imc-enable-reuse: "true" # Enables the ImageCache reuse feature.
spec:
  images:
  - centos:latest
  - busybox:latest
  imagePullSecrets:
  - default:secret1
  - default:secret2
  - kube-system:secret3
  imageCacheSize:
   25
  retentionDays:
   7

Parameter description:

Create an ImageCache

1. Create an ImageCache.

   kubectl create -f imagecache-test.yaml

   Sample imagecache-test.yaml file:

   apiVersion: eci.alibabacloud.com/v1
   kind: ImageCache
   metadata:
     name: imagecache-sample-test
     annotations:
       k8s.aliyun.com/imc-enable-reuse: "true" # Enables the ImageCache reuse feature.
   spec:
     images:
     - registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
     - registry.cn-shanghai.aliyuncs.com/eci_open/busybox:1.30
     imageCacheSize:
      25
     retentionDays:
      7

2. View the status of the ImageCache.

   kubectl get imagecache imagecache-sample-test

   The following sample code provides a sample output. If the ImageCache is in the Ready state, the ImageCache is created and can be used.

   NAME                     AGE     CACHEID                    PHASE   PROGRESS
   imagecache-sample-test   5m30s   imc-2ze2kbf9l1onf03z****   Ready   100%

Query an ImageCache

You can query details about an ImageCache or the ImageCache list in a cluster.

• Query the ImageCache list in a cluster

  kubectl get imagecache

• Query details about an ImageCache

  kubectl get imagecache <imagecache-name> -o yaml

Delete an ImageCache

An ImageCache is a snapshot. If you want to retain an ImageCache that you manually created, you must pay the snapshot cost. If you no longer use the ImageCache, we recommend that you manually delete it in a timely manner.

If you want to delete an ImageCache, run the following command:

kubectl delete imagecache <imagecache-name>