Accepted: k8s on harvester hci

The Context

Kubernetes is a standard for managing containerized applications. Harvester, an open-source HCI software built on Kubernetes, manages virtual machines, storage, and network resources. Installing Rancher on Harvester enhances Kubernetes management.

The Problem Statement

The challenge is installing Rancher directly on a Harvester VM using the rancher-vcluster addon, which allows Rancher Manager to run as a workload on the Harvester cluster.

Solution

The solution involves:

  1. Installing the rancher-vcluster Addon The rancher-vcluster addon is not packaged with Harvester, but you can find it in the experimental-addons repository.

Assuming you are using the Harvester kubeconfig, you can run the following command to apply the YAML file:

ssh rancher@xxx.xxx.xxx.xx
sudo kubectl apply -f https://raw.githubusercontent.com/harvester/experimental-addons/main/rancher-vcluster/rancher-vcluster.yaml
# Users can define the rancher url and password via addon interface.
# hostname: "rancher.172.19.108.3.sslip.io"
# password: "hunter2"
# Open https://rancher.192.168.0.65.sslip.io/dashboard/auth/setup

This command will fetch the rancher-vcluster.yaml file from the experimental-addons repository and apply it to your Kubernetes cluster.

  1. Configuring the Addon: Configure the addon through the Harvester UI under Advanced > Addons. Edit the config for the rancher-vcluster addon, specify a hostname that points to the Harvester VIP and set a bootstrap password for Rancher.
  2. Accessing Rancher: Access Rancher using the DNS hostname provided during configuration after installation.

This approach integrates Rancher into Harvester, leveraging Harvester’s infrastructure to manage both VMs and containers centrally.

To forcefully remove a Kubernetes namespace that is stuck in the Terminating state, you can follow these steps:

  1. Edit the namespace to remove its finalizers:

    First, you’ll need to edit the namespace to remove any finalizers that are preventing it from being deleted.

    kubectl get namespace rancher-vcluster -o json > tmp.json

  2. Open the tmp.json file and remove the finalizers field:

    Look for the spec section and remove the finalizers array. It should look something like this:

    "spec": {
  "finalizers": [
    "kubernetes"
  ]
}

    After removal, it should look like this:

    "spec": {}

  3. Apply the modified JSON back to the cluster:

    kubectl replace --raw "/api/v1/namespaces/rancher-vcluster/finalize" -f ./tmp.json

  4. Verify the namespace has been deleted:

    kubectl get namespaces

If the namespace still does not delete, you may need to manually clean up resources within the namespace before retrying the above steps.

Important Note:

Forcefully removing a namespace can lead to orphaned resources. Ensure that you understand the implications of this action and have backups if necessary.

The Benefits

This setup enables creation and management of Kubernetes clusters through Harvester’s integration with Rancher and deployment of a Kubernetes cluster based on specific requirements (K3s).

The Downsides

The process can be complex and requires attention to detail. Misconfiguration could lead to issues with the installation or operation of Harvester and Rancher.

The Road Not Taken

An alternative could be a network-based installation method, not feasible in an air-gapped environment.

The Infrequent Use Case

This setup is useful in environments where internet access is restricted or unavailable, necessitating the use of the rancher-vcluster addon.

In Core and Done by Us

The user performs the entire process of installing and configuring the rancher-vcluster addon with guidance from this proposal.

Status

Status: Accepted

Decision Makers

  • V-Sekai development team

Tags

  • V-Sekai

Further Reading

  1. V-Sekai · GitHub - Official GitHub account for the V-Sekai development community focusing on social VR functionality for the Godot Engine
  2. V-Sekai/v-sekai-game - GitHub page for the V-Sekai open-source project bringing social VR/VRSNS/metaverse components to the Godot Engine
  3. Rancher Vcluster

AI assistant Aria assisted with this article.