Role info

This playbook is not for fully setting up a Kubernetes Cluster.

It only helps you automate the standard Kubernetes bootstrapping pre-reqs.

Supported OS

• Ubuntu 24.04
• Ubuntu 22.04
• Ubuntu 20.04
• Ubuntu 18.04

Required Ansible

Ansible version required 2.10+

Tasks in the role

This role contains tasks to:

• Install basic packages required
• Setup standard system requirements - Disable Swap, Modify sysctl, Disable SELinux
• Install and configure a container runtime of your Choice - cri-o, Docker, Containerd
• Install the Kubernetes packages - kubelet, kubeadm and kubectl

How to use this role

• Clone the Project:

$ git clone https://github.com/cloudspinx/k8s-bootstrap.git

• Configure /etc/hosts file in your bastion or workstation with all nodes and ip addresses. Example:

192.168.200.10 k8smaster01.example.com k8smaster01
192.168.200.11 k8smaster02.example.com k8smaster02
192.168.200.12 k8smaster03.example.com k8smaster03

192.168.200.13 k8snode01.example.com k8snode01
192.168.200.14 k8snode02.example.com k8snode02
192.168.200.15 k8snode03.example.com k8snode03
192.168.200.16 k8snode04.example.com k8snode04

• Update your inventory, for example:

$ vim hosts
[k8snodes]
k8smaster01
k8smaster02
k8smaster03
k8snode01
k8snode02
k8snode03
k8snode04

• Update variables in playbook file

$ vim k8s-prep.yml
---
- name: Prepare Kubernetes Nodes for Cluster bootstrapping
  hosts: k8snodes
  remote_user: root
  become: yes
  become_method: sudo
  #gather_facts: no
  vars:
    k8s_version: "1.32"                                  # Kubernetes version to be installed
    timezone: "UTC"                                      # Timezone to set on all nodes
    k8s_cni: calico                                      # calico, flannel
    container_runtime: cri-o                             # docker, cri-o, containerd 
    pod_network_cidr: "172.18.0.0/16"                    # pod subnet if using cri-o runtime
    # Docker proxy support
    setup_proxy: false                                   # Set to true to configure proxy
    proxy_server: "proxy.example.com:8080"               # Proxy server address and port
    docker_proxy_exclude: "localhost,127.0.0.1"          # Adresses to exclude from proxy
  roles:
    - kubernetes-bootstrap

If you are using non root remote user, then set username and enable sudo:

become: yes
become_method: sudo

To enable proxy, set the value of setup_proxy to true and provide proxy details.

Running Playbook

Once all values are updated, you can then run the playbook against your nodes.

NOTE: Recommended to disable. if you must enable, a pattern in hostname is required for master and worker nodes:

Check playbook syntax to ensure no errors:

$ ansible-playbook --syntax-check k8s-prep.yml -i hosts

playbook: k8s-prep.yml

Playbook executed as root user - with ssh key:

$ ansible-playbook -i hosts k8s-prep.yml

Playbook executed as root user - with password:

$ ansible-playbook -i hosts k8s-prep.yml --ask-pass

Playbook executed as sudo user - with password:

$ ansible-playbook -i hosts k8s-prep.yml --ask-pass --ask-become-pass

Playbook executed as sudo user - with ssh key and sudo password:

$ ansible-playbook -i hosts k8s-prep.yml --ask-become-pass

Playbook executed as sudo user - with ssh key and passwordless sudo:

$ ansible-playbook -i hosts k8s-prep.yml --ask-become-pass

Execution should be successful without errors:

TASK [kubernetes-bootstrap : Reload firewalld] *********************************************************************************************************
changed: [k8smaster01]
changed: [k8snode01]
changed: [k8snode02]

PLAY RECAP *********************************************************************************************************************************************
k8smaster01                : ok=23   changed=3    unreachable=0    failed=0    skipped=11   rescued=0    ignored=0
k8snode01                  : ok=23   changed=3    unreachable=0    failed=0    skipped=11   rescued=0    ignored=0
k8snode02                  : ok=23   changed=3    unreachable=0    failed=0    skipped=11   rescued=0    ignored=0

Next check article on bootsrapping k8s control plane: https://computingforgeeks.com/how-to-install-kubernetes-on-ubuntu-complete-steps/