Create an admin cluster

This document shows how to create an admin cluster for Google Distributed Cloud. The admin cluster runs the Kubernetes control plane for the admin cluster itself and for the associated user clusters. You must create an admin cluster before you create any user clusters to run your workloads.

For more details about the admin cluster, see the installation overview.

Procedure overview

These are the primary steps involved in creating an admin cluster:

  1. Connect to your admin workstation.
    This VM has the necessary tools to create new clusters.
  2. Fill in your configuration files.
    Specify the details for your new admin cluster by completing and validating an admin cluster configuration file, a credentials configuration file, and possibly an IP block file.
  3. Import OS images to vSphere, and push container images to the private registry if applicable.
    Run gkectl prepare.
  4. (Optional) Create a Seesaw load balancer.
    If you have decided to use the Seesaw load balancer, run gkectl create loadbalancer.
  5. Create an admin cluster.
    Use gkectl to create a new admin cluster as specified in your completed configuration files. The onprem-admin-cluster-controller in the temporary bootstrap cluster manages admin cluster creation.
  6. Verify that your admin cluster is running.
    Use kubectl to view your cluster nodes.

At the end of this procedure, you will have a running admin cluster that you can use to create and manage user clusters.

Before you begin

  • Ensure that you have created an admin workstation.

  • Review the IP addresses planning document. Ensure that you have enough IP addresses available, and revisit your decision about how you want your cluster nodes to get their IP addresses: DHCP or static. If you decide to use static IP addresses, you must fill in an IP block file that contains your chosen addresses.

  • Review the load balancing overview and revisit your decision about the kind of load balancer you want to use. For certain load balancers, you must set up the load balancer before you create your admin cluster.

  • Look ahead at the privateRegistry section, and decide whether you want to use a public or private registry for Google Distributed Cloud components.

  • Look ahead at the osImageType field, and decide what type of operating system you want to run on your admin cluster nodes

1. Connect to your admin workstation

Follow the instructions to get an SSH connection to your admin workstation. The admin workstation has the tools you need to create your admin cluster. The admin workstation also has your component access service account activated.

Do all the remaining steps in this topic on your admin workstation in the home directory.

2. Fill in your configuration file

When gkeadm created your admin workstation, it generated a configuration file named admin-cluster.yaml. This configuration file is for creating your admin cluster.

Familiarize yourself with the configuration file by scanning the admin cluster configuration file document. You might want to keep this document open in a separate tab or window, because you will refer to it as you complete the following steps.

name

If you want to specify a name for your admin cluster, fill in the name field.

bundlePath

The bundle is a zipped file that contains cluster components. It is included with the admin workstation. This field is already filled in for you.

vCenter

Most of the fields in this section are already filled in with values that you entered when you created your admin workstation. The exception is the dataDisk field, which you must fill in now.

network

Decide how you want your cluster nodes to get their IP addresses. The options are:

  • From a DHCP server that you set up ahead of time. Set network.ipMode.type to "dhcp".

  • From a list of static IP addresses that you provide. Set network.ipMode.type to "static", and create an IP block file that provides the static IP addresses. For an example of an IP block file, see Example of filled-in configuration files.

Fill in the rest of the fields in the network section of the configuration file as needed:

  • If you have decided to use static IP addresses for your cluster nodes, the network.ipMode.ipBlockFilePath field and the network.hostconfig section are required. The network.hostconfig section holds information about NTP servers, DNS servers, and DNS search domains used by your cluster nodes.

    If you are using the Seesaw load balancer, the network.hostconfig section is required even if you intend to use DHCP for your cluster nodes.

  • The network.podCIDR and network.serviceCIDR fields have prepopulated values that you can leave unchanged unless they conflict with addresses already being used in your network. Kubernetes uses these ranges to assign IP addresses to Pods and Services in your cluster.

Regardless of whether you rely on a DHCP server or specify a list of static IP addresses, you need to have enough IP addresses available for your admin cluster nodes. This includes the nodes in the admin cluster that run the control planes for any associated user clusters. For an explanation of how many IP addresses you need, see Plan your IP addresses.

loadBalancer

Set aside a VIP for the Kubernetes API server of your admin cluster. Set aside another VIP for the add-ons server. Provide your VIPs as values for loadBalancer.vips.controlPlaneVIP and loadBalancer.vips.addonsVIP.

For more information, see VIPs in the admin cluster subnet.

Decide what type of load balancing you want to use. The options are:

  • MetalLB bundled load balancing. Set loadBalancer.kind to "MetalLB".

  • Seesaw bundled load balancing. Set loadBalancer.kind to "Seesaw", and fill in the loadBalancer.seesaw section.

  • Integrated load balancing with F5 BIG-IP. Set loadBalancer.kind to "F5BigIP", and fill in the f5BigIP section.

  • Manual load balancing. Set loadBalancer.kind to "ManualLB", and fill in the manualLB section.

For more information about load balancing options, see Overview of load balancing.

antiAffinityGroups

Set antiAffinityGroups.enabled to true or false according to your preference.

Use this field to specify whether you want Google Distributed Cloud to create VMware Distributed Resource Scheduler (DRS) anti-affinity rules for your admin cluster nodes, causing them to be spread across at least three physical hosts in your data center.

adminMaster

If you want to specify CPU and memory for the control-plane node of the admin cluster, fill in the adminMaster.

addonNode

Set addonNode.autoResize.enabled to true or false according to your preference.

proxy

If the network that will have your admin cluster nodes is behind a proxy server, fill in the proxy section.

privateRegistry

Decide where you want to keep container images for the Google Distributed Cloud components. The options are:

  • Container Registry

  • Your own private Docker registry.

If you want to use your own private registry, fill in the privateRegistry section.

componentAccessServiceAccountKeyPath

Google Distributed Cloud uses your component access service account to download cluster components from Container Registry. This field holds the path of a JSON key file for your component access service account.

This field is already filled in for you.

gkeConnect

Register your admin cluster to a Google Cloud fleet by filling in the gkeConnect section.

stackdriver

If you want to enable Cloud Logging and Cloud Monitoring for your cluster, fill in the stackdriver section.

This is section is required by default. That is, if you don't fill in this section, you must you include the --skip-validation-stackdriver flag when you run gkectl create admin.

cloudAuditLogging

If you want to integrate the audit logs from your cluster's Kubernetes API server with Cloud Audit Logs, fill in the cloudAuditLogging section.

clusterBackup

If you want to enable backing up of the admin cluster, set clusterBackup.datastore to the vSphere datastore where you want to save cluster backups.

autoRepair

If you want to enable automatic node repair for your admin cluster, set autoRepair.enabled to true.

secretsEncryption

If you want to enable always-on Secrets encryption, fill in the secretsEncryption section.

osImageType

Decide what type of OS image you want to use for the admin cluster nodes, and fill in the osImageType section accordingly.

Example of filled-in configuration files

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

vc-01-ipblock.yaml

blocks:
  - netmask: 255.255.252.0
    gateway: 172.16.23.254
    ips:
    - ip: 172.16.20.10
      hostname: admin-host1
    - ip: 172.16.20.11
      hostname: admin-host2
    - ip: 172.16.20.12
      hostname: admin-host3
    - ip: 172.16.20.13
      hostname: admin-host4
    - ip: 172.16.20.14
      hostname: admin-host5
    - ip: 172.16.20.15
      hostname: admin-host6
    - ip: 172.16.20.16
      hostname: admin-host7
    - ip: 172.16.20.17
      hostname: admin-host8

vc-01-admin-cluster.yaml

apiVersion: v1
kind: AdminCluster
name: "gke-admin-01"
bundlePath: "/var/lib/gke/bundles/gke-onprem-vsphere-1.11.0-gke.543-full.tgz"
vCenter:
  address: "vc01.example"
  datacenter: "vc-01"
  cluster: "vc01-workloads-1"
  resourcePool: "vc-01-pool-1"
  datastore: "vc01-datastore-1"
  caCertPath: "/usr/local/google/home/me/certs/vc01-cert.pem""
  credentials:
    fileRef:
      path: "credential.yaml"
      entry: "vCenter"
  dataDisk: "vc01-admin-disk.vmdk"
network:
  hostConfig:
    dnsServers:
    - "203.0.113.1"
    - "198.51.100.1"
    ntpServers:
    - "216.239.35.4"
  ipMode:
    type: "static"
    ipBlockFilePath: "vc-01-ipblock.yaml"
  serviceCIDR: "10.96.232.0/24"
  podCIDR: "192.168.0.0/16"
  vCenter:
    networkName: "vc01-net-1"
loadBalancer:
  vips:
    controlPlaneVIP: "172.16.20.59"
    addonsVIP: "172.16.20.60"
  kind: "MetalLB"
antiAffinityGroups:
  enabled: true
componentAccessServiceAccountKeyPath: "sa-key.json"
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"
  disableVsphereResourceMetrics: false
clusterBackup:
  datastore: "vc-01-datastore-bu"
autoRepair:
  enabled: true
osImageType: "ubuntu_containerd"

Validate your configuration file

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

gkectl check-config --config ADMIN_CLUSTER_CONFIG

Replace ADMIN_CLUSTER_CONFIG with the path of your admin 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.

3. Get OS images

Run gkectl prepare to initialize your vSphere environment:

gkectl prepare --config ADMIN_CLUSTER_CONFIG

The gkectl prepare command performs the following preparatory tasks:

  • Imports OS images to vSphere and marks them as VM templates.

  • If you are using a private Docker registry, pushes the container images to your registry.

  • Optionally, validates the container images' build attestations, thereby verifying the images were built and signed by Google and are ready for deployment.

4. (Optional) Create a Seesaw load balancer

Recall that you have several load balancing options for your admin cluster: Metal LB, Seesaw, F5 BIG-IP, or manual.

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

Create and configure the VMs for your Seesaw load balancer:

gkectl create loadbalancer --config ADMIN_CLUSTER_CONFIG

5. Create the admin cluster

Create the admin cluster:

gkectl create admin --config ADMIN_CLUSTER_CONFIG

Resume creation of the admin cluster after a failure

If the admin cluster creation fails or is canceled, you can run the create command again:

gkectl create admin --config ADMIN_CLUSTER_CONFIG

Locate the admin cluster kubeconfig file

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

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

kubectl config get-clusters --kubeconfig ADMIN_CLUSTER_KUBECONFIG

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

NAME
gke-admin-tqk8x

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

Manage the checkpoint.yaml file

When you ran the gkectl create admin command to create the admin cluster, it created a checkpoint file in the same datastore folder as the admin cluster data disk. By default, this file has the name DATA_DISK_NAME‑checkpoint.yaml. If the length of DATA_DISK_NAME is greater than or equal to 245 characters, then, due to the vSphere limit on filename length, the name is DATA_DISK_NAME.yaml.

This file contains the admin cluster state and credentials, and is used for future upgrades. Do not delete this file unless you are following the process for deleting an admin cluster.

If you have enabled VM encryption in your instance of vCenter Server, then you must have the Cryptographic operations.Direct Access privilege before you create or upgrade your admin cluster. Otherwise the checkpoint will not be uploaded. If you cannot obtain this privilege, then you can disable uploading the checkpoint file by using the hidden flag --disable-checkpoint when you run a relevant command.

The checkpoint.yaml file is automatically updated when you run the gkectl upgrade admin command, or when you run a gkectl update command that affects the admin cluster.

6. Verify that your admin cluster is running

Verify that your admin cluster is running:

kubectl get nodes --kubeconfig ADMIN_CLUSTER_KUBECONFIG

Replace ADMIN_CLUSTER_KUBECONFIG with the path of your admin cluster kubeconfig file.

The output shows the admin cluster nodes. For example:

gke-admin-master-hdn4z            Ready    control-plane,master ...
gke-admin-node-7f46cc8c47-g7w2c   Ready ...
gke-admin-node-7f46cc8c47-kwlrs   Ready ...

7. Back up files

We recommend that you back up your admin cluster kubeconfig file. That is, copy the kubeconfig file from your admin workstation to another location. Then if you lose access to the admin workstation, or if the kubeconfig file on your admin workstation gets accidentally deleted, you still have access to the admin cluster.

We also recommend that you back up the private SSH key for your admin cluster. Then if you lose access to the admin cluster, you can still use SSH to connect to the admin cluster nodes. This will allow you to troubleshoot and investigate any issues with connectivity to the admin cluster.

Extract the SSH key from the admin cluster to a file named admin-cluster-ssh-key:

kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG get secrets -n kube-system sshkeys \
    -o jsonpath='{.data.vsphere_tmp}' | base64 -d > admin-cluster-ssh-key

Now you can back up admin-cluster-ssh-key to another location of your choice.

Troubleshooting

See Troubleshooting cluster creation and upgrade.

What's next

Create a user cluster