Schedule pods to ECI on virtual nodes

How it works

Alibaba Cloud Elastic Container Instance (ECI) is a serverless elastic compute service designed for containers. It provides a maintenance-free, strongly isolated, and quick-to-start container runtime environment. When you use ECI, you do not need to purchase or manage underlying ECS nodes, allowing you to focus on your applications instead of infrastructure. You can create ECIs on demand and pay only for the resources configured for your containers on a pay-as-you-go, per-second basis.

Typically, your cluster has at least one group of IDC nodes. When you create a pod, it is scheduled to run on one of these nodes. This architecture works well for services with stable traffic. If your business has unpredictable traffic spikes, you can use virtual nodes to schedule pods directly to ECI. This approach eliminates node creation time, prevents idle node resources, and reduces costs.

Step 1: Configure RAM permissions

Step 2: Install the ack-virtual-node component

onectl addon install ack-virtual-node

Addon ack-virtual-node, version **** installed.

Step 3: Schedule pods to run on ECI

After you deploy the ack-virtual-node component, you can use virtual nodes to schedule pods to ECI. This section describes common ways to schedule pods to ECI in a registered cluster. Before you schedule pods, make sure the virtual node is in the Ready state.

1. Run the following command to check the status of the virtual node:

   kubectl get no | grep virtual-kubelet

   Expected output:

   virtual-kubelet-cn-hangzhou-b   Ready    agent                  18d   v1.20.11-aliyun.1

   The output indicates that the virtual node is in the Ready state.

2. You can use one of the following three methods to schedule pods to run on ECI.

   Method 1: Configure pod labels (For clusters of version 1.16 or later)

   Add the label alibabacloud.com/eci=true to a pod to schedule it as an ECI pod on a virtual node. The following example shows how to do this:

   1. Run the following command to add the label to the pod:

   kubectl run nginx --image nginx -l alibabacloud.com/eci=true

   2. Run the following command to view the pod:

   kubectl get pod -o wide | grep virtual-kubelet

   3. Expected output:

   nginx-7fc9f746b6-r4xgx     0/1     ContainerCreating   0          20s   192.168.XX.XX   virtual-kubelet        <none>           <none>

   Method 2: Configure namespace labels

   Add the label alibabacloud.com/eci=true to a namespace. All pods subsequently created in that namespace will run as ECI pods on a virtual node. The following example shows how to do this:

   1. Run the following command to create a namespace:

   kubectl create ns vk

   2. Run the following command to add the label to the namespace:

   kubectl label namespace vk alibabacloud.com/eci=true

   3. Run the following command to schedule a pod to the virtual node in the namespace:

   kubectl -n vk run nginx --image nginx

   4. Run the following command to view the pod:

   kubectl -n vk get pod -o wide | grep virtual-kubelet

   5. Expected output:

   nginx-6f489b847d-vgj4d      1/1     Running             0          1m   192.168.XX.XX   virtual-kubelet        <none>           <none>

   Method 3: Specify a node name

   You can schedule a pod to a specific virtual node by adding nodeName: <YOUR_VIRTUAL_NODE_NAME> to the pod's spec. The pod then runs as an ECI pod on that virtual node. The following example shows how to do this:

   1. Create a file named nginx-deployment.yaml with the following content:

   apiVersion: apps/v1 # for versions before 1.8.0 use apps/v1beta1
   kind: Deployment
   metadata:
     name: nginx-deployment-basic
     labels:
       app: nginx
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         nodeName: <YOUR_VIRTUAL_NODE_NAME>             # Replace with the name of your virtual node. Run 'kubectl get no' to find it.
         containers:
         - name: nginx
           image: nginx:1.7.9 # Replace with your image and tag.
           ports:
           - containerPort: 80
           resources:
             limits:
               cpu: "500m"

   2. Run the following command to create the application:

   kubectl apply -f nginx-deployment.yaml

   3. Run the following command to view the pods:

   kubectl get pod -o wide | grep virtual-kubelet

   4. Expected output:

   nginx-6f489b847d-XXX      1/1     Running             0          1m   192.168.XX.XX   virtual-kubelet        <none>           <none>
   nginx-6f489b847d-XXX      1/1     Running             0          1m   192.168.XX.XX   virtual-kubelet        <none>           <none>

Related operations

kubectl edit configmap eci-profile -n kube-system

data:
  enableClusterIp: "true"
  enableHybridMode: "false"
  enablePrivateZone: "false"
  securityGroupId: sg-2zeeyaaxlkq9sppl****
  selectors: ""
  vSwitchIds: vsw-2ze23nqzig8inprou****,vsw-2ze94pjtfuj9vaymf****     # The vSwitches for ECI pods. You can specify multiple vSwitch IDs, separated by commas (,).
  vpcId: vpc-2zeghwzptn5zii0w7****