Question

是否可以根据时间自动重启Pod？

例如，我想每天早上8:00 AM重新启动集群的容器。

Answer 1

有一个特定的资源：CronJob

这里有个例子：

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: your-cron
spec:
  schedule: "*/20 8-19 * * 1-5"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        metadata:
          labels:
            app: your-periodic-batch-job
        spec:
          containers:
          - name: my-image
            image: your-image
            imagePullPolicy: IfNotPresent
          restartPolicy: OnFailure

Answer 2

使用cronjob，但不运行您的Pod，而是安排一个Kubernetes API命令，该命令将每天重新启动部署（kubectl rollout restart）。这样，如果出现问题，旧的吊舱将不会掉落或移除。

部署可以创建新的副本集，并等待它们启动，然后杀死旧的pod并重新路由流量。服务将继续不间断。

您必须设置RBAC，以便从集群内部运行的Kubernetes客户端有权执行对Kubernetes API的必要调用。

---
# Service account the client will use to reset the deployment,
# by default the pods running inside the cluster can do no such things.
kind: ServiceAccount
apiVersion: v1
metadata:
  name: deployment-restart
  namespace: <YOUR NAMESPACE>
---
# allow getting status and patching only the one deployment you want
# to restart
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: deployment-restart
  namespace: <YOUR NAMESPACE>
rules:
  - apiGroups: ["apps", "extensions"]
    resources: ["deployments"]
    resourceNames: ["<YOUR DEPLOYMENT NAME>"]
    verbs: ["get", "patch", "list", "watch"] # "list" and "watch" are only needed
                                             # if you want to use `rollout status`
---
# bind the role to the service account
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: deployment-restart
  namespace: <YOUR NAMESPACE>
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: deployment-restart
subjects:
  - kind: ServiceAccount
    name: deployment-restart
    namespace: <YOUR NAMESPACE>

cronjob规范本身：

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: deployment-restart
  namespace: <YOUR NAMESPACE>
spec:
  concurrencyPolicy: Forbid
  schedule: '0 8 * * *' # cron spec of time, here, 8 o'clock
  jobTemplate:
    spec:
      backoffLimit: 2 # this has very low chance of failing, as all this does
                      # is prompt kubernetes to schedule new replica set for
                      # the deployment
      activeDeadlineSeconds: 600 # timeout, makes most sense with 
                                 # "waiting for rollout" variant specified below
      template:
        spec:
          serviceAccountName: deployment-restart # name of the service
                                                 # account configured above
          restartPolicy: Never
          containers:
            - name: kubectl
              image: bitnami/kubectl # probably any kubectl image will do,
                                     # optionaly specify version, but this
                                     # should not be necessary, as long the
                                     # version of kubectl is new enough to
                                     # have `rollout restart`
              command:
                - 'kubectl'
                - 'rollout'
                - 'restart'
                - 'deployment/<YOUR DEPLOYMENT NAME>'

（可选）如果希望cronjob等待部署开始，请将cronjob命令更改为：

command:
 - bash
 - -c
 - >-
   kubectl rollout restart deployment/<YOUR DEPLOYMENT NAME> &&
   kubectl rollout status deployment/<YOUR DEPLOYMENT NAME>

Answer 3

我从@ Ryan Lowe 借来了想法，但做了一些修改。它将在24小时之前重新启动Pod

      livenessProbe:
        exec:
          command:
             - bin/sh
            - -c
            - "end=$(date -u +%s);start=$(stat -c %Z /proc/1 | awk '{print int($1)}'); test $(($end-$start)) -lt 86400"

Answer 4

根据cronjob-in-kubernetes-to-restart-delete-the-pod-in-a-deployment 您可以创建具有kind: CronJob的{{1}}的{{1}}。因此，您的CronJob将以jobTemplate为一天的启动这些容器（直到重新启动）。根据您的示例，此时将containers分配给上午8:00

Answer 5

对于另一个具有始终重新启动策略（该cron作业不应该处理-参见creating a cron job spec pod template）的Pod，另一个快速而肮脏的选项是一个livenessProbe，它只是测试时间然后按照指定的时间表重新启动广告连播

例如启动后，请等待一个小时，然后每分钟检查一次，如果小时是3（AM），则失败探测并重新启动，否则通过

livenessProbe:
  exec:
    command:
    - exit $(test $(date +%H) -eq 3 && echo 1 || echo 0)
  failureThreshold: 1
  initialDelaySeconds: 3600
  periodSeconds: 60

时间间隔取决于您返回日期并测试;）

当然，如果您已经将活动度探针用作实际活动度探针¯\ _（ツ）_ /¯

，则此方法将不起作用

Answer 6

从@Ryan Lowe答案中，如果已有的应用程序只想添加到配置中：

oc set probe dc/myapp --liveness --initial-delay-seconds=1800 --period-seconds=600 --failure-threshold=1 -- bash -c 'exit $(test $(date +%H) -eq 8 && echo 1 || echo 0)'

Reference

Kubernetes-如何安排Pod重新启动

6 个答案: