how to configure an eci-profile to automatically use DataCache - Elastic Container Instance

When you run many pods that depend on a DataCache, manually adding the DataCache annotation to each pod spec is error-prone and hard to maintain. The ECI Effect capability in eci-profiles lets you automatically inject the DataCache annotation into any pod that matches a label selector — no changes to individual pod specs required.

This topic explains how to configure an eci-profile selector to automatically add the k8s.aliyun.com/eci-data-cache-bucket annotation to pods that carry specific labels.

How it works

eci-profiles evaluate pod labels against all configured selectors. If a pod matches a selector's namespaceSelector or objectSelector criteria, eci-profile injects the annotations defined in the selector's effect field into the pod.

Prerequisites

Before you begin, ensure that you have:

kubectl access to the cluster with permission to edit ConfigMaps in the kube-system namespace
A bucket for storing DataCache data

Configure the eci-profile selector

Selector fields

Each entry in the selectors array must include a name field. The following fields are also available:

Field	Required	Description
`name`	Yes	A unique identifier for this selector
`namespaceSelector`	No	Matches pods based on the labels of their namespace. Use this to apply the annotation to all pods in namespaces that carry specific labels.
`objectSelector`	No	Matches pods based on the pod's own labels. Use this to target individual pods by their labels.
`effect`	No	The annotations and labels to inject into matching pods

Add a DataCache selector

Edit the eci-profile ConfigMap.

kubectl -n kube-system edit cm eci-profile

Add a selector in the selectors section. The following example automatically injects the k8s.aliyun.com/eci-data-cache-bucket: "default" annotation into any pod labeled data-cache: "true".

data:
  selectors: |
    [
      {
        "name": "datacache-selector",
        "objectSelector": {
          "matchLabels": {
            "data-cache": "true"
          }
        },
        "effect": {
          "annotations": {
            "k8s.aliyun.com/eci-data-cache-bucket": "default"
          }
        }
      }
    ]

Create a DataCache. For more information, see Create a DataCache.

Create a pod using the DataCache.

kubectl create -f test-edc.yaml

The following is a sample test-edc.yaml. The pod carries the data-cache: "true" label, which triggers eci-profile to inject the k8s.aliyun.com/eci-data-cache-bucket: "default" annotation automatically.

Important

When creating a pod with a DataCache, you must specify the bucket that stores the DataCache and the path in which the data is stored by using the HostPath parameter.

apiVersion: v1
kind: Pod
metadata:
  name: test-edc
  labels:
    alibabacloud.com/eci: "true"
    data-cache: "true"   # Triggers eci-profile to inject the k8s.aliyun.com/eci-data-cache-bucket annotation
spec:
  containers:
    - name: model
      image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
      command: ["sleep", "999999"]
      volumeMounts:
        - name: "model"
          mountPath: "/model"
  volumes:
    - name: "model"
      hostPath:
        path: "/model/test"   # Required: path where DataCache data is stored. Replace with the actual path.

What's next

Configure an eci-profile — Learn about the full eci-profile structure and all available fields.
Create a DataCache — Create and manage DataCache resources.