Using k0sctl - Documentation (original) (raw)

Install using k0sctl#

k0sctl is a command-line tool for bootstrapping and managing k0s clusters. k0sctl connects to the provided hosts using SSH and gathers information on the hosts, with which it forms a cluster by configuring the hosts, deploying k0s, and then connecting the k0s nodes together.

k0sctl deployment

With k0sctl, you can create multi-node clusters in a manner that is automatic and easily repeatable. This method is recommended for production cluster installation.

Note: The k0sctl install method is necessary for automatic upgrade.

Prerequisites#

You can execute k0sctl on any system that supports the Go language. Pre-compiled k0sctl binaries are available on the k0sctl releases page).

Note: For target host prerequisites information, refer to the k0s System Requirements.

Install k0s#

1. Install k0sctl tool#

k0sctl is a single binary, the instructions for downloading and installing of which are available in the k0sctl github repository.

2. Configure the cluster#

  1. Run the following command to create a k0sctl configuration file:
    k0sctl init > k0sctl.yaml
    This action creates a k0sctl.yaml file in the current directory:
    `apiVersion: k0sctl.k0sproject.io/v1beta1
    kind: Cluster
    metadata:
    name: k0s-cluster
    spec:
    hosts:
  1. Provide each host with a valid IP address that is reachable by k0sctl, and the connection details for an SSH connection.

Note: Refer to the k0sctl documentation for k0sctl configuration specifications.

3. Deploy the cluster#

Run k0sctl apply to perform the cluster deployment:

`$ k0sctl apply --config k0sctl.yaml

⠀⣿⣿⡇⠀⠀⢀⣴⣾⣿⠟⠁⢸⣿⣿⣿⣿⣿⣿⣿⡿⠛⠁⠀⢸⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠀█████████ █████████ ███ ⠀⣿⣿⡇⣠⣶⣿⡿⠋⠀⠀⠀⢸⣿⡇⠀⠀⠀⣠⠀⠀⢀⣠⡆⢸⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀███ ███ ███ ⠀⣿⣿⣿⣿⣟⠋⠀⠀⠀⠀⠀⢸⣿⡇⠀⢰⣾⣿⠀⠀⣿⣿⡇⢸⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠀███ ███ ███ ⠀⣿⣿⡏⠻⣿⣷⣤⡀⠀⠀⠀⠸⠛⠁⠀⠸⠋⠁⠀⠀⣿⣿⡇⠈⠉⠉⠉⠉⠉⠉⠉⠉⢹⣿⣿⠀███ ███ ███ ⠀⣿⣿⡇⠀⠀⠙⢿⣿⣦⣀⠀⠀⠀⣠⣶⣶⣶⣶⣶⣶⣿⣿⡇⢰⣶⣶⣶⣶⣶⣶⣶⣶⣾⣿⣿⠀█████████ ███ ██████████

k0sctl v0.21.0 Copyright 2023, k0sctl authors. INFO ==> Running phase: Connect to hosts INFO [ssh] 10.0.0.1:22: connected INFO [ssh] 10.0.0.2:22: connected INFO ==> Running phase: Detect host operating systems INFO [ssh] 10.0.0.1:22: is running Ubuntu 20.10 INFO [ssh] 10.0.0.2:22: is running Ubuntu 20.10 INFO ==> Running phase: Prepare hosts INFO [ssh] 10.0.0.1:22: installing kubectl INFO ==> Running phase: Gather host facts INFO [ssh] 10.0.0.1:22: discovered 10.12.18.133 as private address INFO ==> Running phase: Validate hosts INFO ==> Running phase: Gather k0s facts INFO ==> Running phase: Download K0s on the hosts INFO [ssh] 10.0.0.2:22: downloading k0s v1.34.2+k0s.0 INFO [ssh] 10.0.0.1:22: downloading k0s v1.34.2+k0s.0 INFO ==> Running phase: Configure K0s WARN [ssh] 10.0.0.1:22: generating default configuration INFO [ssh] 10.0.0.1:22: validating configuration INFO [ssh] 10.0.0.1:22: configuration was changed INFO ==> Running phase: Initialize K0s Cluster INFO [ssh] 10.0.0.1:22: installing k0s controller INFO [ssh] 10.0.0.1:22: waiting for the k0s service to start INFO [ssh] 10.0.0.1:22: waiting for kubernetes api to respond INFO ==> Running phase: Install workers INFO [ssh] 10.0.0.1:22: generating token INFO [ssh] 10.0.0.2:22: writing join token INFO [ssh] 10.0.0.2:22: installing k0s worker INFO [ssh] 10.0.0.2:22: starting service INFO [ssh] 10.0.0.2:22: waiting for node to become ready INFO ==> Running phase: Disconnect from hosts INFO ==> Finished in 2m2s INFO k0s cluster version v1.34.2+k0s.0 is now installed INFO Tip: To access the cluster you can now fetch the admin kubeconfig using: INFO k0sctl kubeconfig `

4. Access the cluster#

To access your k0s cluster, use k0sctl to generate a kubeconfig for the purpose.

k0sctl kubeconfig > kubeconfig

With the kubeconfig, you can access your cluster using either kubectl or Lens.

kubectl get pods --kubeconfig kubeconfig -A

NAMESPACE NAME READY STATUS RESTARTS AGE kube-system calico-kube-controllers-5f6546844f-w8x27 1/1 Running 0 3m50s kube-system calico-node-vd7lx 1/1 Running 0 3m44s kube-system coredns-5c98d7d4d8-tmrwv 1/1 Running 0 4m10s kube-system konnectivity-agent-d9xv2 1/1 Running 0 3m31s kube-system kube-proxy-xp9r9 1/1 Running 0 4m4s kube-system metrics-server-6fbcd86f7b-5frtn 1/1 Running 0 3m51s

Known limitations#

Next Steps#