Kubespray Deployment and Configuration

In this solution, the Kubernetes (K8s) cluster is deployed using a modified Kubespray (based on tag v2.26.0) with a non-root depuser account from the Jump Node. The modifications in Kubespray are designed to meet the DPF prerequisites as described in the User Manual and facilitate cluster deployment and scaling.

Our modified Kubespray installs Flannel CNI for the primary Kubernetes network.

1. Download the modified Kubespray archive: modified_kubespray_v2.26.0.tar.gz.

2. Extract the contents and navigate to the extracted directory:

   Jump Node Console

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   $ tar -xzf /home/depuser/modified_kubespray_v2.26.0.tar.gz
   $ cd kubespray/
   depuser@jump:~/kubespray$
           

3. Verify that the network plugin is set to flannel and that kube_proxy_remove is set to false in the inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml file.

   inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml

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   [depuser@jump kubespray-2.26.0]$ vim inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml
   # Choose network plugin (cilium, calico, kube-ovn, weave or flannel. Use cni for generic cni plugin)
   # Can also be set to 'cloud', which lets the cloud provider setup appropriate routing
   kube_network_plugin: flannel
   ....
   # Kube-proxy proxyMode configuration.
   # Can be ipvs, iptables
   kube_proxy_remove: false
   kube_proxy_mode: ipvs
   .....
           

4. Set the K8s API VIP address and DNS record. Replace it with your own IP address and DNS record if different:

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   depuser@jump:~/kubespray$ sed -i '/  #kube_vip_address:/s/.*/kube_vip_address: 10.0.110.10/' inventory/mycluster/group_vars/k8s_cluster/addons.yml
   depuser@jump:~/kubespray$ sed -i '/apiserver_loadbalancer_domain_name:/s/.*/apiserver_loadbalancer_domain_name: "kube-vip.dpf.rdg.local.domain"/' roles/kubespray-defaults/defaults/main/main.yml
           

5. Install the necessary dependencies and set up the Python virtual environment:

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   depuser@jump:~/kubespray$ sudo apt -y install python3-pip jq python3.12-venv
   depuser@jump:~/kubespray$ python3 -m venv .venv
   depuser@jump:~/kubespray$ source .venv/bin/activate
   (.venv) depuser@jump:~/kubespray$ python3 -m pip install --upgrade pip
   (.venv) depuser@jump:~/kubespray$ pip install -U -r requirements.txt
   (.venv) depuser@jump:~/kubespray$ pip install ruamel-yaml
           

6. Review and edit the inventory/mycluster/hosts.yaml file to define the cluster nodes. The following is the configuration for this deployment:

   inventory/mycluster/hosts.yaml

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   all:
     hosts:
       master1:
         ansible_host: 10.0.110.1
         ip: 10.0.110.1
         access_ip: 10.0.110.1
         node_labels:
           "k8s.ovn.org/zone-name": "master1"
       master2:
         ansible_host: 10.0.110.2
         ip: 10.0.110.2
         access_ip: 10.0.110.2
         node_labels:
           "k8s.ovn.org/zone-name": "master2"
       master3:
         ansible_host: 10.0.110.3
         ip: 10.0.110.3
         access_ip: 10.0.110.3
         node_labels:
           "k8s.ovn.org/zone-name": "master3"
     children:
       kube_control_plane:
         hosts:
           master1:
           master2:
           master3:
       kube_node:
         hosts:
       etcd:
         hosts:
           master1:
           master2:
           master3:
       k8s_cluster:
         children:
           kube_control_plane: