创建MySQL StatefulSet时遭遇Kubernetes未知字段错误求助

错误信息 #

执行kubectl apply时出现以下错误：

C:\Users\Azvmadmin15\.docker\YAML>kubectl apply -f mysqlpvc.yaml
service/mysql-srv created

Error from server (BadRequest): 
error when creating "mysqlpvc.yaml": StatefulSet in version "v1" cannot be handled as a StatefulSet: strict decoding error: unknown field "spec.template.spec.ports", unknown field "spec.template.spec.volumeMounts"

当前集群资源状态 #

# 获取所有资源
C:\Users\Azvmadmin15\.docker\YAML>kubectl get all
NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP    78m
service/mysql-srv    ClusterIP   10.108.13.118   <none>        3306/TCP   17m

# 获取PV状态
C:\Users\Azvmadmin15\.docker\YAML>kubectl get pv
NAME              CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
mysql-pv-volume   10Gi       RWO            Retain           Bound    default/mysql-pv-claim   manual                  64m

# 获取PVC状态
C:\Users\Azvmadmin15\.docker\YAML>kubectl get pvc
NAME             STATUS   VOLUME            CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mysql-pv-claim   Bound    mysql-pv-volume   10Gi       RWO            manual         67m

所用YAML文件内容 #

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql-ss
spec:
  replicas: 1
  selector:
    matchLabels:
      app: "mysql-pod"
  serviceName: "mysql"
  template:
    metadata:
      labels:
        app: "mysql-pod"
    spec:
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: tiger1234
      ports:
      - containerPort: 3306
        name: mysql
      volumeMounts:
      - name: mysql-persistent-storage
        mountPath: /var/lib/mysql

---

apiVersion: v1
kind: Service
metadata:
  name: mysql-srv
spec:
  ports:
  - port: 3306
  selector:
    app: "mysql"

问题原因与修复方案 #

核心问题 #

1. 字段位置错误：ports和volumeMounts是容器级别的配置，必须嵌套在containers数组的具体容器条目下，而不是和containers同级放在spec.template.spec下。Kubernetes无法识别错误位置的字段，因此抛出解码错误。
2. 服务标签不匹配：Service的selector设置为app: "mysql"，但StatefulSet模板中Pod的标签是app: "mysql-pod"，会导致服务无法关联到Pod。
3. StatefulSet的serviceName不匹配：StatefulSet的serviceName需要指向已存在的Headless Service名称，原配置中写的mysql与实际创建的mysql-srv不一致。

修正后的YAML文件 #

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql-ss
spec:
  replicas: 1
  selector:
    matchLabels:
      app: "mysql-pod"
  serviceName: "mysql-srv" # 与下方Service名称保持一致
  template:
    metadata:
      labels:
        app: "mysql-pod"
    spec:
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: tiger1234
        ports: # 移至containers条目内部
        - containerPort: 3306
          name: mysql
        volumeMounts: # 移至containers条目内部
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql

---

apiVersion: v1
kind: Service
metadata:
  name: mysql-srv
spec:
  clusterIP: None # 改为Headless Service，适配StatefulSet的网络需求
  ports:
  - port: 3306
    targetPort: 3306
  selector:
    app: "mysql-pod" # 与Pod标签保持匹配

执行步骤 #

1. 删除已创建的错误Service：

kubectl delete service mysql-srv

2. 应用修正后的YAML文件：

kubectl apply -f mysqlpvc.yaml

3. 验证资源状态：

kubectl get statefulset mysql-ss
kubectl get pods -l app=mysql-pod
kubectl get service mysql-srv

内容的提问来源于stack exchange，提问作者Balaji