Create a user cluster (kubeception)

This document shows how to create a user cluster that uses kubeception.

What is kubeception?

The term kubeception is used to convey the idea that a Kubernetes cluster is used to create and manage other Kubernetes clusters. In the context of Google Distributed Cloud, kubeception refers to the case where the control plane for a user cluster runs on one or more nodes in an admin cluster.

We don't recommend using kubeception. Instead, we recommend using Controlplane V2. With Controlplane V2, the control-plane nodes for the user cluster are in the user cluster itself.

Plan your IP addresses

Follow the instructions in Plan your IP addresses (kubeception).

Fill in a cluster configuration file

Follow the instructions in Create a user cluster (Controlplane V2).

As you fill in your user cluster configuration file:

Example of filled-in configuration files

Here is an example of a filled-in IP block file and a filled-in user cluster configuration file. The configuration enables some, but not all, of the available features.

user-ipblock.yaml

blocks:
  - netmask: 255.255.252.0
    gateway: 172.16.23.254
    ips:
    - ip: 172.16.20.21
      hostname: user-host1
    - ip: 172.16.20.22
      hostname: user-host2
    - ip: 172.16.20.23
      hostname: user-host3
    - ip: 172.16.20.24
      hostname: user-host4

user-cluster.yaml

apiVersion: v1
kind: UserCluster
name: "my-user-cluster"
gkeOnPremVersion: 1.15.0-gke.581
enableControlplaneV2: false
network:
  hostConfig:
    dnsServers:
    - "203.0.113.1"
    - "198.51.100.1"
    ntpServers:
    - "216.239.35.4"
  ipMode:
    type: static
    ipBlockFilePath: "user-ipblock.yaml"
  serviceCIDR: 10.96.0.0/20
  podCIDR: 192.168.0.0/16
loadBalancer:
  vips:
    controlPlaneVIP: "172.16.20.32"
    ingressVIP: "172.16.21.30"
  kind: "MetalLB"
  metalLB:
    addressPools:
    - name: "my-address-pool"
      addresses:
      - "172.16.21.30 - 172.16.21.39"
enableDataplaneV2: true
masterNode:
  cpus: 4
  memoryMB: 8192
  replicas: 1
nodePools:
- name: "my-node-pool"
  cpus: 4
  memoryMB: 8192
  replicas: 3
  osImageType: "ubuntu_containerd"
  enableLoadBalancer: true
antiAffinityGroups:
  enabled: true
gkeConnect:
  projectID: "my-project-123"
  registerServiceAccountKeyPath: "connect-register-sa-2203040617.json"
stackdriver:
  projectID: "my-project-123"
  clusterLocation: "us-central1"
  enableVPC: false
  serviceAccountKeyPath: "log-mon-sa-2203040617.json"
autoRepair:
  enabled: true

Validate your configuration file

After you've filled in your user cluster configuration file, run gkectl check-config to verify that the file is valid:

gkectl check-config --kubeconfig ADMIN_CLUSTER_KUBECONFIG --config USER_CLUSTER_CONFIG

Replace the following:

  • ADMIN_CLUSTER_KUBECONFIG: the path of the kubeconfig file for your admin cluster

  • USER_CLUSTER_CONFIG: the path of your user cluster configuration file

If the command returns any failure messages, fix the issues and validate the file again.

If you want to skip the more time-consuming validations, pass the --fast flag. To skip individual validations, use the --skip-validation-xxx flags. To learn more about the check-config command, see Running preflight checks.

(Optional) Create a Seesaw load balancer for your user cluster

If you have chosen to use the bundled Seesaw load balancer, do the step in this section. Otherwise, skip this section.

Create and configure the VMs for your Seesaw load balancer:

gkectl create loadbalancer --kubeconfig ADMIN_CLUSTER_KUBECONFIG --config USER_CLUSTER_CONFIG

(Optional) Import OS images to vSphere, and push container images to a private registry

Run gkectl prepare if any of the following are true:

  • Your user cluster is in a different vSphere data center from your admin cluster.

  • Your user cluster has a different vCenter Server from your admin cluster.

  • Your user cluster uses a private container registry that is different from the private registry used by your admin cluster.

gkectl prepare --kubeconfig ADMIN_CLUSTER_KUBECONFIG \ 
    --bundle-path BUNDLE \
    --user-cluster-config USER_CLUSTER_CONFIG

Replace the following:

  • ADMIN_CLUSTER_KUBECONFIG: the path of your admin cluster kubeconfig file

  • BUNDLE: the path of the bundle file. This file is on your admin workstation in /var/lib/gke/bundles/. For example:

    /var/lib/gke/bundles/gke-onprem-vsphere-1.14.0-gke.421-full.tgz

  • USER_CLUSTER_CONFIG: the path of your user cluster configuration file

Create the user cluster

Run the following command to create the user cluster:

gkectl create cluster --kubeconfig ADMIN_CLUSTER_KUBECONFIG --config USER_CLUSTER_CONFIG

Locate the user cluster kubeconfig file

The gkectl create cluster command creates a kubeconfig file named USER_CLUSTER_NAME-kubeconfig in the current directory. You will need this kubeconfig file later to interact with your user cluster.

The kubeconfig file contains the name of your user cluster. To view the cluster name, you can run:

kubectl config get-clusters --kubeconfig USER_CLUSTER_KUBECONFIG

The output shows the name of the cluster. For example:

NAME
my-user-cluster

If you like, you can change the name and location of your kubeconfig file.

Verify that your user cluster is running

Run the following command to verify that your user cluster is running:

kubectl get nodes --kubeconfig USER_CLUSTER_KUBECONFIG

Replace USER_CLUSTER_KUBECONFIG with the path of your user cluster kubeconfig file.

The output shows the user cluster nodes. For example:

my-user-cluster-node-pool-69-d46d77885-7b7tx   Ready ...
my-user-cluster-node-pool-69-d46d77885-lsvzk   Ready ...
my-user-cluster-node-pool-69-d46d77885-sswjk   Ready ...

Troubleshooting

See Troubleshooting cluster creation and upgrade.

What's next