k8s通过virtual

k8s通过virtual

1、环境信息

同 k8s+virtual-kubelet部署带动态pv的pod到openstack-zun

2、创建带cinder动态pv的pod

具体创建过程参考
k8s+virtual-kubelet部署带动态pv的pod到openstack-zun

3、pod创建失败

pod处于pending状态

3.1、pod状态

查看pod列表

# kubectl get pods -o wide
NAME              READY   STATUS    RESTARTS   AGE   IP               NODE               NOMINATED NODE      READINESS GATES
testpvcpod        0/1     Pending   0          22s   <none>           <none>             <none>              <none>

3.2、pod详细信息

查看出问题的pod详细信息，问题出在调度上，调度失败的原因有两个

3.2.1、4 node(s) had taints that the pod didn’t tolerate

这个问题的原因是4个master和1个普通node都有taint，本例主要验证使用两个virtual-kubelet node部署pod，所以这儿不做修改

3.2.2、2 node(s) had volume node affinity conflict

该问题是本例要解决的问题

# kubectl describe pods testpvcpod
...
Events:Type     Reason            Age        From               Message----     ------            ----       ----               -------Warning  FailedScheduling  <unknown>  default-scheduler  persistentvolumeclaim "testpvc" not foundWarning  FailedScheduling  <unknown>  default-scheduler  persistentvolumeclaim "testpvc" not foundWarning  FailedScheduling  <unknown>  default-scheduler  0/6 nodes are available: 2 node(s) had volume    node affinity conflict, 4 node(s) had taints that the pod didn't tolerate.Warning  FailedScheduling  <unknown>  default-scheduler  0/6 nodes are available: 2 node(s) had volume    node affinity conflict, 4 node(s) had taints that the pod didn't tolerate.

3.3 查看pv和pvc信息

3.3.1、列出pv和pvc

# kubectl get pvc
NAME                               STATUS   VOLUME                                     CAPACITY   ACCESS    MODES   STORAGECLASS   AGE
testpvc                            Bound    pvc-c9e46b6b-cd52-474d-9835-8f5757ac5ec7   2Gi        RWO               standard       26m
[root@k8s-m1 test]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                         STORAGECLASS   REASON   AGE
pvc-c9e46b6b-cd52-474d-9835-8f5757ac5ec7   2Gi        RWO            Delete           Bound    default/te   stpvc                            standard                26m

可以看到pv和pvc信息都正常创建了

3.3.2 查看pv详细信息

从pv详细信息中，pv有节点亲和的需求

Node Affinity:Required Terms:Term 0:        failure-domain.beta.kubernetes.io/zone in 

# kubectl describe pv pvc-c9e46b6b-cd52-474d-9835-8f5757ac5ec7
Name:              pvc-c9e46b6b-cd52-474d-9835-8f5757ac5ec7
Labels:            failure-domain.beta.kubernetes.io/zone=nova
Annotations:       kubernetes.io/createdby: cinder-dynamic-provisionerpv.kubernetes.io/bound-by-controller: yespv.kubernetes.io/provisioned-by: kubernetes.io/cinder
Finalizers:        [kubernetes.io/pv-protection]
StorageClass:      standard
Status:            Bound
Claim:             default/testpvc
Reclaim Policy:    Delete
Access Modes:      RWO
VolumeMode:        Filesystem
Capacity:          2Gi
Node Affinity:Required Terms:Term 0:        failure-domain.beta.kubernetes.io/zone in [nova]
Message:
Source:Type:       Cinder (a Persistent Disk resource in OpenStack)VolumeID:   9ac04a59-146c-4300-9030-58c1e153c2f1FSType:ReadOnly:   falseSecretRef:  nil
Events:         <none>

4、解决问题

通过第三节分析，pv有节点亲和的需求
所以需要给节点打上相应的标签

4.1、打标签

# kubectl label node virtual-kubelet failure-domain.beta.kubernetes.io/zone=nova
node/virtual-kubelet labeled

4.2、重新部署pod

# kubectl delete -f testpvc.yaml
pod "testpvcpod" deleted# kubectl apply -f testpvc.yaml
pod/testpvcpod created
persistentvolumeclaim/testpvc created

4.3、pod部署成功

# kubectl get pods
NAME              READY   STATUS    RESTARTS   AGE
testpvcpod        1/1     Running   0          4m29s