In this quick start we’re going to show how to get started with KubeOne on GCE. We’ll cover how to create the needed infrastructure using our example Terraform scripts and then install Kubernetes. Finally, we’re going to show how to destroy the cluster along with the infrastructure.
As a result, you’ll get Kubernetes High-Available (HA) clusters with three control plane nodes and one worker node.
To follow this quick start, you’ll need:
The provided credentials are deployed to the cluster to be used by machine-controller for creating worker nodes. You may want to consider providing a non-administrator credentials to increase the security.
In order for Terraform to successfully create the infrastructure and for machine-controller to create worker nodes, you need an Service Account with the appropriate permissions. These are:
gcloud CLI is installed, a service account can be created like follow:
# create new service account gcloud iam service-accounts create k1-cluster-provisioner # get your service account id gcloud iam service-accounts list # get your project id gcloud projects list # create policy binding gcloud projects add-iam-policy-binding YOUR_PROJECT_ID --member 'serviceAccount:YOUR_SERVICE_ACCOUNT_ID' --role='roles/compute.admin' gcloud projects add-iam-policy-binding YOUR_PROJECT_ID --member 'serviceAccount:YOUR_SERVICE_ACCOUNT_ID' --role='roles/iam.serviceAccountUser' gcloud projects add-iam-policy-binding YOUR_PROJECT_ID --member 'serviceAccount:YOUR_SERVICE_ACCOUNT_ID' --role='roles/viewer'
A Google Service Account for the platform has to be created, see Creating and managing service accounts. The result is a JSON file containing the fields
# create a new json key for your service account gcloud iam service-accounts keys create --iam-account YOUR_SERVICE_ACCOUNT k1-cluster-provisioner-sa-key.json
Once you have the Service Account, you need to set
# export JSON file content of created service account json key export GOOGLE_CREDENTIALS=$(cat ./k1-cluster-provisioner-sa-key.json)
Also, the Compute Engine API has to be enabled for the project in the Google APIs Console.
KubeOne is based on the Bring-Your-Own-Infra approach, which means that you have to provide machines and needed resources yourself. To make this task easier we are providing Terraform scripts that you can use to get started. You’re free to use your own scripts or any other preferred approach.
The Terraform scripts for GCE are located in the
KubeOne comes with the Terraform integration that can source information about
the infrastructure directly from the Terraform output. If you decide not to use
our Terraform scripts, but you still want to use the Terraform integration, you
must ensure that your
Terraform output (
is using the same format as ours. Alternatively, if you decide not to use Terraform,
you can provide needed information about the infrastructure manually in the
KubeOne configuration file.
First, we need to switch to the directory with Terraform scripts:
Before we can use Terraform to create the infrastructure for us, Terraform needs
to download the GCE plugin. This is done by running the
You need to run this command only the first time before using scripts.
You may want to configure the provisioning process by setting variables defining
the cluster name, GCE region, instances size and similar. The easiest way is to
terraform.tfvars file and store variables there. This file is
automatically read by Terraform.
For the list of available settings along with their names please see the
variables.tf file. You should consider setting:
|cluster_name||yes||cluster name and prefix for cloud resources|
|project||yes||GCP Project ID|
|region||europe-west3||GCP region to use for all resources|
|ssh_public_key_file||~/.ssh/id_rsa.pub||path to your SSH public key that’s deployed on instances|
|control_plane_type||n1-standard-1||control plane instance type (note that you should have at least 2 GB RAM and 2 CPUs for Kubernetes to work properly)|
terraform.tfvars file can look like:
cluster_name = "demo" project = "kubeone-demo-project" region = "europe-west1"
Now that you configured Terraform you can use the
plan command to see what
changes will be made:
Finally, if you agree with changes you can proceed and provision the infrastructure:
terraform apply -var control_plane_target_pool_members_count=1
control_plane_target_pool_members_count is needed in order to bootstrap
the control plane successfully. Once install is done it’s recommended
to include all control plane VMs into the LB (will be covered a bit
later in this document).
Shortly after you’ll be asked to enter
yes to confirm your intention to
provision the infrastructure.
Infrastructure provisioning takes around 5 minutes.
Once the provisioning is done, you need to export the Terraform output using the following command. This Terraform output file will be used by KubeOne to source information about the infrastructure and worker nodes.
terraform output -json > tf.json
The generated output is based on the
If you want to change any settings, such as how worker nodes are created,
you can modify the
output.tf file. Make sure to run
terraform output again after modifying the file.
Now that you have the infrastructure you can proceed with provisioning your Kubernetes cluster using KubeOne.
Before you start, you’ll need a configuration file that defines how Kubernetes
will be installed, e.g. what version will be used and what features will be
enabled. For the configuration file reference run
kubeone config print --full.
To get started you can use the following configuration file:
apiVersion: kubeone.io/v1alpha1 kind: KubeOneCluster versions: kubernetes: '1.18.0' cloudProvider: name: 'gce' cloudConfig: | [global] regional = true
This configuration manifest instructs KubeOne to provision Kubernetes 1.18.0
cluster on GCE. Other properties, including information about the infrastructure
and how to create worker nodes are sourced from the Terraform output.
As KubeOne is using Kubermatic
for creating worker nodes, see the GCE example manifest
for available options.
If control plane nodes are created in multiple zones,
you must configure
kube-controller-manager to support regional clusters by
fail to create the needed routes and other cloud resources, without which
the cluster can’t function properly. The example Terraform configuration
creates control plane nodes in multiple zones by default.
Finally, we’re going to install Kubernetes by using the
install command and
providing the configuration file and the Terraform output:
kubeone install -m config.yaml --tfjson <DIR-WITH-tfstate-FILE>
Alternatively, if the terraform state file is in the current working directory
--tfjson . can be used as well.
The installation process takes some time, usually 5-10 minutes. The output should look like the following one:
INFO[17:24:41 EET] Installing prerequisites… INFO[17:24:42 EET] Determine operating system… node=22.214.171.124 INFO[17:24:42 EET] Determine operating system… node=126.96.36.199 INFO[17:24:42 EET] Determine operating system… node=188.8.131.52 INFO[17:24:42 EET] Determine hostname… node=184.108.40.206 INFO[17:24:42 EET] Creating environment file… node=220.127.116.11 INFO[17:24:42 EET] Installing kubeadm… node=18.104.22.168 os=ubuntu INFO[17:24:43 EET] Deploying configuration files… node=22.214.171.124 os=ubuntu INFO[17:24:43 EET] Determine hostname… node=126.96.36.199 INFO[17:24:43 EET] Creating environment file… node=188.8.131.52 INFO[17:24:43 EET] Installing kubeadm… node=184.108.40.206 os=ubuntu INFO[17:24:43 EET] Determine hostname… node=220.127.116.11 INFO[17:24:43 EET] Deploying configuration files… node=18.104.22.168 os=ubuntu INFO[17:24:43 EET] Creating environment file… node=22.214.171.124 INFO[17:24:43 EET] Installing kubeadm… node=126.96.36.199 os=ubuntu INFO[17:24:43 EET] Deploying configuration files… node=188.8.131.52 os=ubuntu INFO[17:24:44 EET] Generating kubeadm config file… INFO[17:24:45 EET] Configuring certs and etcd on first controller… INFO[17:24:45 EET] Ensuring Certificates… node=184.108.40.206 INFO[17:24:47 EET] Downloading PKI files… node=220.127.116.11 INFO[17:24:49 EET] Creating local backup… node=18.104.22.168 INFO[17:24:49 EET] Deploying PKI… INFO[17:24:49 EET] Uploading files… node=22.214.171.124 INFO[17:24:49 EET] Uploading files… node=126.96.36.199 INFO[17:24:52 EET] Configuring certs and etcd on consecutive controller… INFO[17:24:52 EET] Ensuring Certificates… node=188.8.131.52 INFO[17:24:52 EET] Ensuring Certificates… node=184.108.40.206 INFO[17:24:54 EET] Initializing Kubernetes on leader… INFO[17:24:54 EET] Running kubeadm… node=220.127.116.11 INFO[17:25:09 EET] Joining controlplane node… INFO[17:26:36 EET] Copying Kubeconfig to home directory… node=18.104.22.168 INFO[17:26:36 EET] Copying Kubeconfig to home directory… node=22.214.171.124 INFO[17:26:36 EET] Copying Kubeconfig to home directory… node=126.96.36.199 INFO[17:26:37 EET] Building Kubernetes clientset… INFO[17:26:39 EET] Applying canal CNI plugin… INFO[17:26:43 EET] Installing machine-controller… INFO[17:26:46 EET] Installing machine-controller webhooks… INFO[17:26:47 EET] Waiting for machine-controller to come up… INFO[17:27:12 EET] Creating worker machines…
Once it’s finished in order in include 2 other control plane VMs into the LB:
KubeOne automatically downloads the Kubeconfig file for the cluster. It’s named
as <cluster_name>-kubeconfig, where <cluster_name> is the name
provided in the
terraform.tfvars file. You can use it with kubectl such as:
or export the
KUBECONFIG environment variable:
You can check the Configure Access To Multiple Clusters document to learn more about managing access to your clusters.
Worker nodes are managed by the machine-controller. By default, it creates
one MachineDeployment object. That object can be scaled up and down
(including to 0) using the Kubernetes API. To do so you first got
to retrieve the
machinedeployments by running:
kubectl get machinedeployments -n kube-system
The names of the
machinedeployments are generated. You can scale the workers
in those using:
kubectl --namespace kube-system scale machinedeployment/<MACHINE-DEPLOYMENT-NAME> --replicas=3
kubectl scale command is not working as expected with kubectl v1.15.
If you want to use the scale command, please upgrade to kubectl v1.16 or newer.
Before deleting a cluster you should clean up all MachineDeployments, so all
worker nodes are deleted. You can do it with the
kubeone reset command:
kubeone reset config.yaml --tfjson <DIR-WITH-tfstate-FILE>
This command will wait for all worker nodes to be gone. Once it’s done you can proceed and destroy the GCE infrastructure using Terraform:
You’ll be asked to enter
yes to confirm your intention to destroy the cluster.
Congratulations! You’re now running Kubernetes HA cluster with three control plane nodes and one worker node. If you want to learn more about KubeOne and its features, make sure to check our documentation.