chore: Bump default Kubernetes version to 1.22.0 (#23)

README.md

@@ -40,6 +40,8 @@ module "k8s" {
   master_server_type = "cx31"
   worker_server_type = "cx31"
   worker_count       = 2
+
+  kubernetes_version = "1.22.0"
 }
 
 output "kubeconfig" {
@@ -58,9 +60,9 @@ and check the access by viewing the created cluster nodes:
 ```cmd
 $ kubectl get nodes --kubeconfig=kubeconfig.conf
 NAME           STATUS   ROLES                  AGE   VERSION
-k8s-master-0   Ready    control-plane,master   31m   v1.21.1
-k8s-worker-0   Ready    <none>                 31m   v1.21.1
-k8s-worker-1   Ready    <none>                 31m   v1.21.1
+k8s-master-0   Ready    control-plane,master   31m   v1.22.0
+k8s-worker-0   Ready    <none>                 31m   v1.22.0
+k8s-worker-1   Ready    <none>                 31m   v1.22.0
 ```
 
 ## High availability setup
@@ -75,7 +77,7 @@ cluster will have to be manually reconfigured (e.g [like this](https://blog.scot
 
 ### Removing/replacing master nodes
 
-A first step before removing a control plane node is to remove its membership in the `etcd` cluster. **Read this section carefully before removing master nodes! If etcd membership is not removed from the prior to the node being shutdown, the whole cluster can become inoperable.** If the master node that is being removed is still functional, the easiest way to remove is by invoking the following command on the node:
+A first step before removing a control plane node is to remove its membership in the `etcd` cluster. **Read this section carefully before removing master nodes! If etcd membership is not removed from the prior to the node being shutdown, the whole cluster can potentially become inoperable.** If the master node that is being removed is still functional, the easiest way to remove is by invoking the following command on the node:
 
 ```cmd
 kubeadm reset --force
@@ -101,6 +103,8 @@ If the node is already defunct, there are two cases to consider:
   Member 2a51630843ac2da6 removed from cluster 46b13f81dcebb93d
   ```
 
+  It is important to remove failed members from etcd even if quorum is still present as new master nodes will not be able to join until etcd cluster is healthy.
+
 - etcd cluster no longer has quorum, e.g. a single master node is gone out of a 2-node cluster. In this case the etcd cluster will need to be rebuilt from snapshot, following the steps for [disaster recovery](https://etcd.io/docs/v3.4/op-guide/recovery/). Data loss may have occured.
 
 

modules/kubernetes-node/scripts/prepare-node.sh.tpl

@@ -21,24 +21,23 @@ sudo sysctl --system
 sudo apt-get update -qq
 sudo apt-get install -qq apt-transport-https ca-certificates curl gnupg lsb-release ipvsadm wireguard
 curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
-sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
-echo  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | \
+curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo gpg --dearmor -o /usr/share/keyrings/kubernetes-archive-keyring.gpg
+echo "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | \
   sudo tee /etc/apt/sources.list.d/docker.list >/dev/null
 echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | \
-  sudo tee /etc/apt/sources.list.d/kubernetes.list
+  sudo tee /etc/apt/sources.list.d/kubernetes.list >/dev/null
 
 # Install container runtime and Kubernetes
 sudo apt-get update -qq
 sudo apt-get install -qq containerd.io kubelet=${kubernetes_version}-00 kubeadm=${kubernetes_version}-00 kubectl=${kubernetes_version}-00
-apt-mark hold kubelet kubeadm kubectl
+sudo apt-mark hold kubelet kubeadm kubectl
 
 # Enable systemd cgroups driver
 sudo mkdir -p /etc/containerd
 containerd config default | \
-  perl -i -pe 's/(\s+)(\[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options\])/\1\2\n\1  SystemdCgroup = true/g' | \
-  sudo tee /etc/containerd/config.toml > /dev/null
+  perl -pe 's/(\s+)(\[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options\])/\1\2\n\1  SystemdCgroup = true/g' | \
+  sudo tee /etc/containerd/config.toml >/dev/null
 
-# Necessary for out-of-tree cloud providers as of 1.21.1 (soon to be deprecated)
 cat <<EOF | sudo tee /etc/systemd/system/kubelet.service.d/20-hcloud.conf > /dev/null
 [Service]
 Environment="KUBELET_EXTRA_ARGS=--cloud-provider=external --node-ip=::"

test/test.sh

@@ -17,7 +17,7 @@ teardown_cluster() {
 
 case "$1" in
 kubectl)
-    curl -LO https://dl.k8s.io/release/v1.21.2/bin/linux/amd64/kubectl
+    curl -LO https://dl.k8s.io/release/v1.22.0/bin/linux/amd64/kubectl
     chmod +x kubectl
     ;;
 setup)

variables.tf

@@ -128,7 +128,7 @@ variable "primary_ip_family" {
 }
 
 variable "kubernetes_version" {
-  description = "Version of Kubernetes to install (default: 1.21.2)"
+  description = "Version of Kubernetes to install (default: 1.22.0)"
   type        = string
-  default     = "1.21.2"
+  default     = "1.22.0"
 }