Prerequisites:

  • The virtual-kubelet node is deployed in the target Kubernetes cluster. Note that a serverless Kubernetes cluster is embedded with the virtual-kubelet node.

Elastic Container Instance (ECI) provides native support for ConfigMaps. You can use a ConfigMap in an ECI in the same way as that in native Kubernetes. 

# kubectl create configmap demo --from-literal=test=configmap
configmap/demo created
# kubectl get configmap demo -o yaml
apiVersion: v1
data:
  test: configmap
kind: ConfigMap
metadata:
  creationTimestamp: "2020-01-20T12:54:42Z"
  name: demo
  namespace: default
  resourceVersion: "15340926"
  selfLink: /api/v1/namespaces/default/configmaps/demo
  uid: 07119167-3b84-11ea-8c0c-4ac7cb9a7625

Save the following sample code in a YAML file named pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: test-configmap
spec:
  nodeName: virtual-kubelet
  containers:
    - name: nginx
      image: nginx:latest
      volumeMounts:
      - name: config-volume
        mountPath: /cache-test
  volumes:
    - name: config-volume
      configMap:
        name: demo
        items:
        - key: test
          path: keys
  restartPolicy: Always

Use the kubectl client to create an ECI based on the preceding configuration file.

# kubectl create -f pod.yaml
pod/test-configmap created
# kubectl get pod test-configmap
NAME             READY   STATUS    RESTARTS   AGE
test-configmap   1/1     Running   0          57s
# kubectl exec -it test-configmap bash
root@test-configmap:/# ls cache-test/
keys
root@test-configmap:/# cat cache-test/keys
configmap
According to the command output, the ConfigMap is mounted to the ECI as a volume.