kubectl drain

Synopsis

Drain node in preparation for maintenance.

The given node will be marked unschedulable to prevent new pods from arriving. ‘drain’ evicts the pods if the API server supports https://kubernetes.io/docs/concepts/workloads/pods/disruptions/ eviction https://kubernetes.io/docs/concepts/workloads/pods/disruptions/ . Otherwise, it will use normal DELETE to delete the pods. The ‘drain’ evicts or deletes all pods except mirror pods (which cannot be deleted through the API server). If there are daemon set-managed pods, drain will not proceed without —ignore-daemonsets, and regardless it will not delete any daemon set-managed pods, because those pods would be immediately replaced by the daemon set controller, which ignores unschedulable markings. If there are any pods that are neither mirror pods nor managed by a replication controller, replica set, daemon set, stateful set, or job, then drain will not delete any pods unless you use —force. —force will also allow deletion to proceed if the managing resource of one or more pods is missing.

‘drain’ waits for graceful termination. You should not operate on the machine until the command completes.

When you are ready to put the node back into service, use kubectl uncordon, which will make the node schedulable again.

https://kubernetes.io/images/docs/kubectl_drain.svg Workflowhttps://kubernetes.io/images/docs/kubectl\_drain.svg

  1. kubectl drain NODE

Examples

  1.   # Drain node "foo", even if there are pods not managed by a replication controller, replica set, job, daemon set, or stateful set on it
  2.   kubectl drain foo --force
  4.   # As above, but abort if there are pods not managed by a replication controller, replica set, job, daemon set, or stateful set, and use a grace period of 15 minutes
  5.   kubectl drain foo --grace-period=900

Options

—chunk-size int     Default: 500

Return large lists in chunks rather than all at once. Pass 0 to disable. This flag is beta and may change in the future.

—delete-emptydir-data

Continue even if there are pods using emptyDir (local data that will be deleted when the node is drained).

—disable-eviction

Force drain to use delete, even if eviction is supported. This will bypass checking PodDisruptionBudgets, use with caution.

—dry-run string[=”unchanged”]     Default: “none”

Must be “none”, “server”, or “client”. If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.

—force

Continue even if there are pods that do not declare a controller.

—grace-period int     Default: -1

Period of time in seconds given to each pod to terminate gracefully. If negative, the default value specified in the pod will be used.

-h, —help

help for drain

—ignore-daemonsets

Ignore DaemonSet-managed pods.

—pod-selector string

Label selector to filter pods on the node

-l, —selector string

Selector (label query) to filter on, supports ‘=’, ‘==’, and ‘!=’.(e.g. -l key1=value1,key2=value2). Matching objects must satisfy all of the specified label constraints.

—skip-wait-for-delete-timeout int

If pod DeletionTimestamp older than N seconds, skip waiting for the pod. Seconds must be greater than 0 to skip.

—timeout duration

The length of time to wait before giving up, zero means infinite

—as string

Username to impersonate for the operation. User could be a regular user or a service account in a namespace.

—as-group strings

Group to impersonate for the operation, this flag can be repeated to specify multiple groups.

—as-uid string

UID to impersonate for the operation.

—cache-dir string     Default: “$HOME/.kube/cache”

Default cache directory

—certificate-authority string

Path to a cert file for the certificate authority

—client-certificate string

Path to a client certificate file for TLS

—client-key string

Path to a client key file for TLS

—cloud-provider-gce-l7lb-src-cidrs cidrs     Default: 130.211.0.0/22,35.191.0.0/16

CIDRs opened in GCE firewall for L7 LB traffic proxy & health checks

—cloud-provider-gce-lb-src-cidrs cidrs     Default: 130.211.0.0/22,209.85.152.0/22,209.85.204.0/22,35.191.0.0/16

CIDRs opened in GCE firewall for L4 LB traffic proxy & health checks

—cluster string

The name of the kubeconfig cluster to use

—context string

The name of the kubeconfig context to use

—default-not-ready-toleration-seconds int     Default: 300

Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.

—default-unreachable-toleration-seconds int     Default: 300

Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.

—disable-compression

If true, opt-out of response compression for all requests to the server

—insecure-skip-tls-verify

If true, the server’s certificate will not be checked for validity. This will make your HTTPS connections insecure

—kubeconfig string

Path to the kubeconfig file to use for CLI requests.

—match-server-version

Require server version to match client version

-n, —namespace string

If present, the namespace scope for this CLI request

—password string

Password for basic authentication to the API server

—profile string     Default: “none”

Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)

—profile-output string     Default: “profile.pprof”

Name of the file to write the profile to

—request-timeout string     Default: “0”

The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don’t timeout requests.

-s, —server string

The address and port of the Kubernetes API server

—storage-driver-buffer-duration duration     Default: 1m0s

Writes in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction

—storage-driver-db string     Default: “cadvisor”

database name

—storage-driver-host string     Default: “localhost:8086”

database host:port

—storage-driver-password string     Default: “root”

database password

—storage-driver-secure

use secure connection with database

—storage-driver-table string     Default: “stats”

table name

—storage-driver-user string     Default: “root”

database username

—tls-server-name string

Server name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used

—token string

Bearer token for authentication to the API server

—user string

The name of the kubeconfig user to use

—username string

Username for basic authentication to the API server

—version version[=true]

—version, —version=raw prints version information and quits; —version=vX.Y.Z… sets the reported version

—warnings-as-errors

Treat warnings received from the server as errors and exit with a non-zero exit code

See Also

  • kubectl - kubectl controls the Kubernetes cluster manager