Ansible Playbooks to install an HA Kubernetes (multi-master) cluster using Kubeadm.

This repository provides Ansible Playbooks to install a Kubernetes HA cluster in an airgapped environment.

• Uses recently GA'd Kubeadm HA joining features

Prerequisites:

• Install Ansible and a forward proxy on the Ansible host

  • Ansible: for macos brew install ansible for linux yum install ansible

• Setup ssh access from Ansible host to Kubernetes nodes. ssh-copy-id -i ~/.ssh/id_rsa.pub <user@host>

Environment preparation:

Specify the Master and Workers in the inventory/*cluster* file:

[k8s-masters] # these are all the masters
[k8s-workers] # these are all the worker nodes

Update the inventory/group_vars/*cluster* section:

• choose the desired versions for kubernetes and docker
• setup the pod network cidr (default setup is for calico - modify in calico.yaml as well)
• specify the version of Helm to use
• specify the Local Storage Provisioner version

Install a highly available kubernetes using kubeadm

You can now run install-all.yaml playbook to get your cluster setup. You can also run the different playbooks separately for different purposes (setting up docker, masters, kubeadm, heml ...).

ansible-playbook -i inventory/cluster1-prod playbooks/install-all.yaml --private-key=~/.ssh/id_rsa -u %username% -v

Restarting the install:

If you need to restart the process using kubeadm reset, please use the uninstall.yaml playbook that deletes the state from all vms.

Upgrade a highly available kubernetes using kubeadm

To upgrade the kubernetes control plane run:

ansible-playbook -i inventory/cluster1-prod playbooks/upgrade-all.yaml --private-key=~/.ssh/id_rsa -u username -v

What install-all.yaml includes:

• Adding the required yum repositories
• Installing docker
• Installing kubeadm, kubelet and kubectl
• Initializing the first master with etcd and kubernetes-api
• Join replica master nodes to the primary master
• Adding the worker nodes to the cluster
• Installing Helm & Tiller
• Installing Local Storage Provisioner
• Enable Azure AD OIDC authentication

Restarting the install:

If you need to restart the process using kubeadm reset, please use the uninstall.yaml playbook that deletes the state from all vms.

To sequentially drain and patch the underlying OS hosts:

ansible-playbook -i inventory/cluster1-prod playbooks/os-patch-updates.yaml --private-key=~/.ssh/id_rsa -u username -v