kubernetes - 将 Statefulset 绑定(bind)到本地持久卷 - 卷节点关联冲突错误

Question

我有3节点kubernetes，主机名为host_1、host_2、host_3。

$ kubectl get nodes
NAME       STATUS    ROLES     AGE       VERSION
host_1     Ready     master    134d      v1.10.1
host_2     Ready     <none>    134d      v1.10.1
host_3     Ready     <none>    134d      v1.10.1

我定义了3个大小为100M的本地持久卷，映射到每个节点上的本地目录。我使用了以下描述符 3 次，其中 <hostname>是以下之一:host_1、host_2、host_3:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: test-volume-<hostname>
spec:
  capacity:
    storage: 100M
  volumeMode: Filesystem
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Delete
  storageClassName: local-storage
  local:
    path: /opt/jnetx/volumes/test-volume
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - <hostname>

应用三个这样的 yaml 后，我得到以下结果:

$ kubectl get pv
NAME                 CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM    STORAGECLASS    REASON    AGE
test-volume-host_1   100M       RWO            Delete           Available            local-storage             58m
test-volume-host_2   100M       RWO            Delete           Available            local-storage             58m
test-volume-host_3   100M       RWO            Delete           Available            local-storage             58m

现在，我有一个非常简单的容器可以写入文件。该文件应位于本地持久卷上。我将其部署为具有 1 个副本的有状态集，并通过有状态集的volumeClaimTemplates 映射卷:

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: filewriter
spec:
  serviceName: filewriter
  ...
  replicas: 1
  template:
    spec:
      containers:
        - name: filewriter
          ...
          volumeMounts:
          - mountPath: /test/data
            name: fw-pv-claim
  volumeClaimTemplates:
  - metadata:
      name: fw-pv-claim
    spec:
      accessModes:
      - ReadWriteOnce
      storageClassName: local-storage
      resources:
        requests:
          storage: 100M

卷声明似乎已正确创建并绑定(bind)到第一个主机上的 pv:

$ kubectl get pv
NAME                 CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                              STORAGECLASS    REASON    AGE
test-volume-host_1   100M       RWO            Delete           Bound       default/fw-pv-claim-filewriter-0   local-storage             1m
test-volume-host_2   100M       RWO            Delete           Available                                      local-storage             1h
test-volume-host_3   100M       RWO            Delete           Available                                      local-storage             1h

但是，pod 挂起在 Pending 状态:

$ kubectl get pods
NAME                         READY     STATUS    RESTARTS   AGE
filewriter-0                 0/1       Pending   0          4s

如果我们描述，我们可以看到以下错误:

$ kubectl describe pod filewriter-0
Name:           filewriter-0
...
Events:
  Type     Reason            Age              From               Message
  ----     ------            ----             ----               -------
  Warning  FailedScheduling  2s (x8 over 1m)  default-scheduler  0/3 nodes are available: 1 node(s) had taints that the pod didn't tolerate, 2 node(s) had volume node affinity conflict. 

你能帮我找出问题所在吗？为什么它不能直接创建 pod？

Answer 1

似乎 PV 可用的一个节点存在您的 StatefulSet 无法容忍的污点。