This page explains how to perform an IP rotation for your control plane in Google Kubernetes Engine (GKE) clusters running version 1.16.10-gke.8 and later.
You can perform an IP rotation to change the IP address that your control plane uses to serve requests from the Kubernetes API. The control plane IP address is static and doesn't change unless you perform an IP rotation.
IP rotation changes the SSL certificate and cluster certificate authority (CA), which limits the ability to connect the previous address with the new one.
IP rotation also occurs as a part of credential rotation.
Before you begin
Before you start, make sure you have performed the following tasks:
- Enable the Google Kubernetes Engine API. Enable Google Kubernetes Engine API
- If you want to use the Google Cloud CLI for this task, install and then initialize the gcloud CLI.
Perform an IP rotation
IP rotation is a multi-step process:
- When you initiate an IP rotation, your control plane begins serving on the new IP address in addition to the original IP address.
- After you initiate a rotation, you must update your cluster's API clients
(such as development machines using the
kubectlcommand-line interface) to begin communicating with the control plane over the new IP address.
- When you complete the rotation, the control plane ceases serving traffic over the previous IP address.
Initiate the rotation
To initiate an IP rotation, run the following command:
gcloud container clusters update CLUSTER_NAME \ --start-ip-rotation
CLUSTER_NAMEwith the name of the cluster.
The output is similar to the following:
This will start an IP Rotation on cluster CLUSTER_NAME. The master will be updated to serve on a new IP address in addition to the current IP address. Google Kubernetes Engine will then schedule recreation of all nodes to point to the new IP address. If maintenance window is used, nodes are not recreated until a maintenance window occurs. See documentation on how to manually update nodes. This operation is long-running and will block other operations on the cluster (including delete) until it has run to completion. Do you want to continue (Y/n)?
This command configures the control plane to serve on two IP addresses: the original address and a new address.
Confirm the rotation and leave the shell open for the operation to complete.
After the control plane has been reconfigured, GKE schedules an update for your cluster's nodes to use the new IP address. Each node pool is marked for recreation. GKE does not finish the IP rotation until the automatic recreation is complete.
If you use maintenance windows,
your nodes are not recreated until a maintenance window occurs. You can manually
recreate all nodes by running the
gcloud container clusters upgrade
command and passing the
--cluster-version flag with the same
GKE version that the node pool is already running.
For more information, see caveats for maintenance windows.
Inspect the rotation
To monitor the node upgrade operation, run the following command:
gcloud container operations list --filter="UPGRADE_NODES RUNNING"
This command returns the operation ID of the node upgrade operation.
To poll the operation, pass the operation ID to the following command:
gcloud container operations wait OPERATION_ID
Node pools are recreated one-by-one, and each has its own operation. If you have multiple node pools, you can use the above instructions to poll each operation.
Update API clients
After initiating IP rotation, you must update all API clients outside the
cluster (such as
kubectl on developer machines) to point to the new IP
To update your API clients, run the following command for each client:
gcloud container clusters get-credentials CLUSTER_NAME
Complete the rotation
After updating API clients outside the cluster, complete the rotation to configure the control plane to serve only on the new IP address.
To complete the rotation, run the following command:
gcloud container clusters update CLUSTER_NAME \ --complete-ip-rotation
The output is similar to the following:
This will complete the in-progress IP Rotation on cluster CLUSTER_NAME. The master will be updated to stop serving on the old IP address and only serve on the new IP address. Make sure all API clients have been updated to communicate with the new IP address (e.g. by running `gcloud container clusters get-credentials --project PROJECT_ID --region COMPUTE_REGION CLUSTER_NAME`). This operation is long-running and will block other operations on the cluster (including delete) until it has run to completion.
If the IP address rotation fails to complete and returns an error message similar to the following, refer to troubleshooting:
ERROR: (gcloud.container.clusters.update) ResponseError: code=400, message=Node pool "test-pool-1" requires recreation.
- Learn about Alias IPs.
- Learn about IP masquerade agent.
- Learn about configuring authorized networks.