kubernetes - 如何安排Pod重新启动

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

使用cronjob，但不要运行您的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，则不会关闭或卸下旧的 pod 。

部署会创建新的ReplicaSet，然后等待它们启动，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>

和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)如果您希望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>