Configuring Specified Node Scheduling (nodeSelector)

In Kubernetes, to schedule a workload to a specified node, simply configure the nodeSelector field in the workload. By setting the target node label in this field, Kubernetes will schedule the workload only to the node with the matching label.

When a node is created, some labels are automatically added to it. You can schedule workloads to the node based on these labels. For details, see Inherent Labels of a Node. The typically used node labels include:

topology.kubernetes.io/zone: the AZ where the node is located, which can be used for scheduling in a specified AZ
kubernetes.io/hostname: hostname of a node, which can be used for specified node scheduling
cce.cloud.com/cce-nodepool: node pool to which a node belongs, which can be used for scheduling in a specified node pool

Prerequisites

If the default labels of a node cannot meet your requirements, you can add custom labels to the node so that workloads can be scheduled based on the labels. For details, see Adding or Deleting a Node Label.

Creating a Workload Scheduled to a Specified Node

Use kubectl to access the cluster. For details, see Accessing a Cluster Using kubectl.

Create a YAML file named nginx.yaml. The file name can be customized.

Configure nodeSelector for the workload. For example, if the key is deploy_qa and the value is true, the pod will be scheduled to the node with the deploy_qa=true label. Example:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      nodeSelector: 
        deploy_qa: "true"
      containers:
      - image: nginx:latest
        imagePullPolicy: IfNotPresent
        name: nginx
      imagePullSecrets:
      - name: default-secret

Create a workload.
```
kubectl apply -f nginx.yaml
```

Verify that all pods run on the target node.

kubectl get pod -o wide

In the following command output, node 192.168.0.103 is labeled with deploy_qa=true:

NAME                     READY   STATUS    RESTARTS   AGE     IP              NODE                                   NOMINATED NODE   READINESS GATES
nginx-66859f4f48-xgp2g   1/1     Running   0          6h57m   172.16.3.0   192.168.0.103   <none>           <none>
nginx-66859f4f48-t9gqj   1/1     Running   0          6h57m   172.16.3.1   192.168.0.103   <none>           <none>
nginx-66859f4f48-2grhq   1/1     Running   0          6h57m   172.16.3.2   192.168.0.103   <none>           <none>