Kubeadm Cluster Ansible Role

This Ansible role will setup a Kuberenetes cluster using Kubeadm. Goals of this role include being both idempotent as well as supporting upgrading existing clusters when necessary. Additionally, a goal is to provide some flexibility with CNI and other settings, however, currently this isn't implemented.

In its current state, this role is incomplete and opinionated. This includes only targeting small clusters with a distributed control plane nodes, and the use of the Calico CNI plugin. In the future, support could be added to have separate control-plane and worker nodes

This role has only been tested with Debian and would need tasks to install required software on RedHat, CentOS, and others.

Requirements

This role has only been tested with Debian, but should support Ubuntu. Support for RHEL and CentOS has not yet been added.

• Ansible - 2.9+ recommended

Variables

The following variables are supported. When using this role, set variables inside the role context. For example:

  roles:
  - name: kubeadm
    vars:
      kube_version: "1.18.1"

kube_version

• Set the version of Kubeadm and Kubernetes to use
  • This field does not use the 'v' prefix before the version
• Default: 1.18.1

kube_cgroup_driver

• Specify which control group driver to use
  • Possible values: cgroupfs, systemd
  • Not currently tested with cgroupfs
• Default: systemd

kube_container_runtime

• Specify which container runtime to use
  • Possible values: containerd
• Default: containerd

kube_custom_cni

• Enable support for customizing CNI plugin use in the cluster, including using the CNI DHCP server
  • This is in addition to the default CNI network plugin deployed such as Calico or Flannel
• Supports the standard CNI plugins which are always included with Kubeadm
• Default: no

kube_systemd_directory

• Base folder for systemd configuration
• Default: /etc/systemd/system