Creating an RKE2 Kubernetes Cluster

Users can now provision RKE2 Kubernetes clusters on top of the Harvester cluster in Rancher v2.6.1+ using the built-in Harvester node driver.

rke2-cluster

Creating an RKE2 Kubernetes Cluster - 图2note

  • VLAN network is required for Harvester node driver.
  • Harvester node driver only supports cloud images.

Create Your Cloud Credentials

  1. Click ☰ > Cluster Management.
  2. Click Cloud Credentials.
  3. Click Create.
  4. Click Harvester.
  5. Enter your cloud credential name
  6. Select “Imported Harvester Cluster”.
  7. Click Create.

create-harvester-cloud-credentials

Create RKE2 Kubernetes Cluster

Users can create a RKE2 Kubernetes cluster from the Cluster Management page via the RKE2 node driver.

  1. Select Clusters menu.
  2. Click Create button.
  3. Toggle Switch to RKE2/K3s.
  4. Select Harvester node driver.
  5. Select a Cloud Credential.
  6. Enter Cluster Name (required).
  7. Enter Namespace (required).
  8. Enter Image (required).
  9. Enter Network Name (required).
  10. Enter SSH User (required).
  11. (optional) Configure the Show Advanced > User Data to install the required packages of VM.
  1. #cloud-config
  2. packages:
  3.   - iptables

Creating an RKE2 Kubernetes Cluster - 图4note

Calico and Canal require the iptables or xtables-nft package to be installed on the node, for more details, please refer to the RKE2 known issues.

  1. Click Create.

create-rke2-harvester-cluster-1 create-rke2-harvester-cluster-2 create-rke2-harvester-cluster-3

Creating an RKE2 Kubernetes Cluster - 图8note

  • RKE2 v1.21.5+rke2r2 or above provides a built-in Harvester Cloud Provider and Guest CSI driver integration.
  • Currently only imported Harvester clusters are supported automatically.

Add Node Affinity

Available as of v1.0.3 + Rancher v2.6.7

The Harvester node driver now supports scheduling a group of machines to particular nodes through the node affinity rules, which can provide high availability and better resource utilization.

Node affinity can be added to the machine pools during the cluster creation:

  1. Click the Show Advanced button and click the Add Node Selectoraffinity-add-node-selector
  2. Set priority to Required if you wish the scheduler to schedule the machines only when the rules are met.

  3. Click Add Rule to specify the node affinity rules, e.g., for the topology spread constraints use case, you can add the region and zone labels as follows:

    1. key: topology.kubernetes.io/region
    2. operator: in list 
    3. values: us-east-1
    4. ---
    5. key: topology.kubernetes.io/zone
    6. operator: in list 
    7. values: us-east-1a

    affinity-add-rules

  4. Click Create to save the node template. After the cluster is installed, you can check whether its machine nodes are scheduled accordingly to the affinity rules.

Using Harvester RKE2 Node Driver in Air Gapped Environment

RKE2 provisioning relies on the qemu-guest-agent package to get the IP of the virtual machine.

Calico and Canal require the iptables or xtables-nft package to be installed on the node.

However, it may not be feasible to install packages in an air gapped environment.

You can address the installation constraints with the following options:

Option 1. Use a VM image with required packages installed.

Option 2. Configure the Show Advanced > User Data to enable the VMs to install required packages via an HTTP(S) proxy.

Example user data in Harvester node template:

  1. #cloud-config
  2. apt:
  3.   http_proxy: http://192.168.0.1:3128
  4.   https_proxy: http://192.168.0.1:3128