Schedule pods to an x86-based virtual node - Elastic Container Instance

For Container Service for Kubernetes (ACK) Serverless clusters, all pods run on virtual nodes without the need to be scheduled. By default, the virtual nodes are x86 architecture. For ACK clusters that use Elastic Compute Service (ECS) instances on real nodes and elastic container instances in virtual nodes, pods are scheduled to real nodes by default. You can schedule pods to virtual nodes based on your business requirements. This topic describes how to schedule pods in an ACK cluster to an x86-based virtual node to run the pods on Elastic Container Instance.

Overview of scheduling methods

You can use one of the following methods to schedule pods to an x86-based virtual node.

Note

To use the following methods, you must modify existing resources. The modification may introduce vulnerabilities into your system. We recommend that you configure an eci-profile to automatically schedule pods that have the specified labels to run on Elastic Container Instance. For more information, see Configure an eci-profile.
If you use the scheduling method of adding a pod label or namespace label or specifying nodeName, the provisioner does not support the WaitForFirstConsumer StorageClass when a dynamically provisioned disk volume is mounted to an Elastic Container Instance-based pod. For more information, see Use a dynamically provisioned disk volume.

Configure pod labels
If you want to schedule a small number of pods to run on Elastic Container Instance, you can add specific labels to the pods. Then, the pods run on the x86-based virtual node.
Configure namespace labels
If you want to schedule a class of pods to run on Elastic Container Instance, you can create a namespace and add a specific label to the namespace. Then, all pods in the namespace run on the x86-based virtual node.
(Not recommended) Other methods
By default, labels and taints are configured for x86-based virtual nodes. You can configure the nodeSelector and tolerations fields for pods to schedule the pods to run on x86-based virtual nodes. You can also specify the nodeName field to schedule pods to run on x86-based virtual nodes.

Method 1: Configure pod labels

You can add an alibabacloud.com/eci=true label to a pod to schedule the pod to run on Elastic Container Instance.

Note

You can also add the eci=true label to pods, but we recommend that you do not use this label.

Procedure:

Create a YAML configuration file for the pod that you want to create.

vim test-pod.yaml

Sample test-pod.yaml file.

apiVersion: v1
kind: Pod
metadata:
  name: nginx1
  labels: 
    alibabacloud.com/eci: "true"   # Add a label.
spec:
  containers:
  - image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
    imagePullPolicy: Always
    name: nginx

Create the pod.
```
kubectl create -f test-pod.yaml 
```

Method 2: Configure namespace labels

You can create a namespace and add an alibabacloud.com/eci=true label to the namespace. Then, all pods in the namespace are scheduled to run on Elastic Container Instance.

Note

You can also add a virtual-node-affinity-injection=enabled label to a namespace, but we recommend that you do not use this label.

Procedure:

Create a namespace.
```
kubectl create ns vk
```

Add a label to the namespace.

kubectl label namespace vk alibabacloud.com/eci=true

Create a YAML configuration file for the pod that you want to create.

vim test-pod.yaml

Sample test-pod.yaml file.

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  namespace: vk  # Specify the namespace to which you added a label in Step 2.
spec:
  containers:
  - image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
    imagePullPolicy: Always
    name: nginx

Create pods.
```
kubectl create -f test-pod.yaml 
```

Method 3: (Not recommended) Other methods

You can use other methods such as configuring the nodeSelector and tolerations fields or specifying the nodeName field to schedule pods to run on Elastic Container Instance.

Procedure:

Create a YAML configuration file for the pod that you want to create.

vim test-pod.yaml

Sample test-pod.yaml file

Configure the nodeSelector and tolerations fields.

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
    imagePullPolicy: Always
    name: nginx
  nodeSelector:     # Configure nodeSelector.
    type: virtual-kubelet
  tolerations:      # Configure tolerations.
  - key: virtual-kubelet.io/provider
    operator: Exists

Specify the nodeName field.

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
    imagePullPolicy: Always
    name: nginx
  nodeName: virtual-kubelet-cn-beijing-g # Specify a node name

Create pods.
```
kubectl create -f test-pod.yaml 
```