创建StatefulSet报Pod未绑定即时PersistentVolumeClaims排查

pod has unbound immediate PersistentVolumeClaims报错的直接原因是Pod声明挂载的PVC找不到匹配的PV完成绑定，结合你贴的配置，按以下顺序排查即可解决：

• 校验引用的StorageClass是否存在
  你的StatefulSet在volumeClaimTemplates里写死了storageClassName: slow，先执行命令确认这个存储类在集群里真实存在：

  kubectl get sc slow
  

  如果返回NotFound，说明根本没有这个名为slow的存储类，PVC没法自动创建PV，自然绑定失败。两种修复方式选一个就行：
  • 集群中创建名为slow的StorageClass，对接可用的存储后端（NFS、本地盘、云盘都可以），配置对应的provisioner实现PV自动动态创建
  • 修改StatefulSet配置，把storageClassName换成集群里已经存在的存储类名，直接删掉这个字段就会使用集群默认的StorageClass
• 检查StorageClass的卷绑定模式
  如果slow存储类确实存在，执行kubectl describe sc slow查看VolumeBindingMode配置项：
  • 如果值是Immediate：PVC一创建就会立刻找PV绑定，如果你用的是节点本地存储，这时候Pod还没调度到具体节点，找不到对应节点上的本地PV就会绑定失败，把绑定模式改成WaitForFirstConsumer即可，等Pod调度到对应节点之后再绑定PV，刚好适配本地存储的节点拓扑限制
  • 如果值已经是WaitForFirstConsumer，继续往下排查
• 静态供给场景手动创建匹配PV
  如果你没配置存储动态供给插件，需要手动创建PV匹配StatefulSet自动生成的PVC。StatefulSet会给每个副本生成独立PVC，命名规则是<卷声明模板名>-<StatefulSet名>-<副本序号>，你这套3副本的配置会生成slow-phponcio-0、slow-phponcio-1、slow-phponcio-2三个PVC，手动创建的PV必须同时满足以下条件才能和PVC绑定：
  • PV的storageClassName必须是slow
  • PV容量不能小于PVC申请的1Gi
  • PV的访问模式必须包含ReadWriteOnce
  • PV没有被其他PVC提前绑定占用
• 清理干扰资源
  你贴的第一个Pod是之前手动创建的独立Pod，标签是run=phponcio，既没有StatefulSet管理的app=phponcio标签，也没挂载slow卷，和这次故障完全没关系，直接执行kubectl delete pod phponcio删掉即可，避免排查时混淆资源。

附相关资源信息 #

异常StatefulSet详情

Name:               phponcio
Namespace:          default
CreationTimestamp:  Thu, 02 Jun 2022 10:35:08 +0200
Selector:           app=phponcio
Labels:             <none>
Annotations:        <none>
Replicas:           3 desired | 1 total
Update Strategy:    RollingUpdate
  Partition:        0
Pods Status:        0 Running / 1 Waiting / 0 Succeeded / 0 Failed
Pod Template:
  Labels:  app=phponcio
  Containers:
   phponcio:
    Image:        84d3f7ba5876/php-apache-mysql
    Port:         80/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:
      /usr/share from slow (rw)
  Volumes:  <none>
Volume Claims:
  Name:          slow
  StorageClass:  slow
  Labels:        <none>
  Annotations:   <none>
  Capacity:      1Gi
  Access Modes:  [ReadWriteOnce]
Events:          <none>

提交的资源YAML

apiVersion: v1
kind: Service
metadata:
  name: phponcio
  labels:
    app: phponcio
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: phponcio
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: phponcio
spec:
  selector:
    matchLabels:
      app: phponcio
  serviceName: phponcio
  replicas: 3
  template:
    metadata:
      labels:
        app: phponcio
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: phponcio
        image: 84d3f7ba5876/php-apache-mysql
        ports:
        - containerPort: 80
          name: phponcio
        volumeMounts:
        - name: slow
          mountPath: /usr/share
  volumeClaimTemplates:
  - metadata:
      name: slow
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: slow
      resources:
        requests:
          storage: 1Gi

集群中存在的无关旧Pod详情

Name:         phponcio
Namespace:    default
Priority:     0
Node:         juanaraque-worknode/10.0.0.2
Start Time:   Wed, 01 Jun 2022 13:49:08 +0200
Labels:       run=phponcio
Annotations:  cni.projectcalico.org/containerID: 768caa8f4e9b0683033e279aa259d6673d81fe38b62a2ea06c7d256805d522f0
              cni.projectcalico.org/podIP: 192.168.240.69/32
              cni.projectcalico.org/podIPs: 192.168.240.69/32
Status:       Running
IP:           192.168.240.69
IPs:
  IP:  192.168.240.69
Containers:
  phponcio:
    Container ID:   docker://75f90344ada396be965f0ae5c33bb7ea8c110d9ea1e014b75f36263b9cd72504
    Image:          84d3f7ba5876/php-apache-mysql
    Image ID:       docker-pullable://84d3f7ba5876/php-apache-mysql@sha256:bf0cd01ae4b77cca146dcd54d8a447ba8b6c7f5a9e11d6dab6d19f429fb111d1
    Port:           <none>
    Host Port:      <none>
    State:          Running
      Started:      Wed, 01 Jun 2022 14:31:53 +0200
    Last State:     Terminated
      Reason:       Error
      Exit Code:    255
      Started:      Wed, 01 Jun 2022 13:54:26 +0200
      Finished:     Wed, 01 Jun 2022 14:30:44 +0200
    Ready:          True
    Restart Count:  2
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-bld5b (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  kube-api-access-bld5b:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
QoS Class:                   BestEffort
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:                      <none>

内容的提问来源于stack exchange，提问作者Jose Matinez