kubernetes - 更新使用 ReadWriteOnce 卷的部署将在装载时失败

Question

我的部署使用了几个卷，所有卷都定义为 ReadWriteOnce 。

将部署应用于干净的集群时，pod 已成功创建。

但是，如果我更新我的部署(即更新容器镜像)，当为我的部署创建一个新的 pod 时，它总是会在卷挂载时失败:

/Mugen$ kubectl get pods
NAME                            READY     STATUS              RESTARTS   AGE
my-app-556c8d646b-4s2kg         5/5       Running             1          2d
my-app-6dbbd99cc4-h442r         0/5       ContainerCreating   0          39m

/Mugen$ kubectl describe pod my-app-6dbbd99cc4-h442r
      Type     Reason                  Age                 From                                             Message
      ----     ------                  ----                ----                                             -------
      Normal   Scheduled               9m                  default-scheduler                                Successfully assigned my-app-6dbbd99cc4-h442r to gke-my-test-default-pool-671c9db5-k71l
      Warning  FailedAttachVolume      9m                  attachdetach-controller                          Multi-Attach error for volume "pvc-b57e8a7f-1ca9-11e9-ae03-42010a8400a8" Volume is already used by pod(s) my-app-556c8d646b-4s2kg
      Normal   SuccessfulMountVolume   9m                  kubelet, gke-my-test-default-pool-671c9db5-k71l  MountVolume.SetUp succeeded for volume "default-token-ksrbf"
      Normal   SuccessfulAttachVolume  9m                  attachdetach-controller                          AttachVolume.Attach succeeded for volume "pvc-2cc1955a-1cb2-11e9-ae03-42010a8400a8"
      Normal   SuccessfulAttachVolume  9m                  attachdetach-controller                          AttachVolume.Attach succeeded for volume "pvc-2c8dae3e-1cb2-11e9-ae03-42010a8400a8"
      Normal   SuccessfulMountVolume   9m                  kubelet, gke-my-test-default-pool-671c9db5-k71l  MountVolume.SetUp succeeded for volume "pvc-2cc1955a-1cb2-11e9-ae03-42010a8400a8"
      Normal   SuccessfulMountVolume   9m                  kubelet, gke-my-test-default-pool-671c9db5-k71l  MountVolume.SetUp succeeded for volume "pvc-2c8dae3e-1cb2-11e9-ae03-42010a8400a8"
      Warning  FailedMount             52s (x4 over 7m)    kubelet, gke-my-test-default-pool-671c9db5-k71l  Unable to mount volumes for pod "my-app-6dbbd99cc4-h442r_default(affe75e0-1edd-11e9-bb45-42010a840094)": timeout expired waiting for volumes to attach or mount for pod "default"/"my-app-6dbbd99cc4-h442r". list of unmounted volumes=[...]. list of unattached volumes=[...]

那么将更改应用于此类部署的最佳策略是什么？为了使用相同的持久性卷，是否必须有一些服务中断？ (我不想创建新卷 - 数据应该维护)

Answer 1

由于访问模式的原因，您将需要容忍这里的中断。这将在创建新 Pod 之前删除现有 Pod(卸载卷)。

“重新创建”的部署策略 - .spec.strategy.type - 将有助于实现这一点: https://github.com/ContainerSolutions/k8s-deployment-strategies/blob/master/recreate/README.md