From 2023f54c59397220d351a2e7004ef38636faa9fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tam=C3=A1s=20G=C3=A9rczei?= <tamas@gerczei.eu>
Date: Tue, 22 Dec 2020 13:24:05 +0100
Subject: [PATCH] initial commit

---
 README.md                | 54 ++++++++++++++++++++++++++++++++++++++++
 k8s-ubuntu-install       | 10 ++++++++
 k8s-ubuntu-update-master | 14 +++++++++++
 k8s-ubuntu-update-os     |  5 ++++
 k8s-ubuntu-update-worker | 13 ++++++++++
 5 files changed, 96 insertions(+)
 create mode 100644 README.md
 create mode 100644 k8s-ubuntu-install
 create mode 100644 k8s-ubuntu-update-master
 create mode 100644 k8s-ubuntu-update-os
 create mode 100644 k8s-ubuntu-update-worker

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..9898b02
--- /dev/null
+++ b/README.md
@@ -0,0 +1,54 @@
+# scripts to deploy / upgrade Kubernetes lab clusters on Ubuntu
+
+### I use Ubuntu (Server 20.04) in order to make use of up-to-date cluster and kernel packages.
+
+# ASSUMPTIONS
+- 2+ available role-dedicated lab nodes (ideally 1 master and 2+ workers) running Ubuntu (I use 4 (1+3) KVM guest domains created via libvirt, YMMV)
+- SSH access to all nodes with pubkey auth
+- sudo as root without password
+- variables named <i>K8S_VERSION_*</i> sent and accepted via SSH
+- one doesn't know Ansible (half-joking there, this is more of an educational, "quick 'n' dirty" effort)
+- one knows there are other, possibly better ways
+
+# INSTALLATION
+ssh master1 bash -xs < k8s-ubuntu-install<br>
+ssh worker1 bash -xs < k8s-ubuntu-install
+
+## generic installation procedure
+- kubeadm init on <strong>master1</strong>
+- kubeadm join on <strong>worker1</strong>
+
+# UPGRADE
+## when upgrading point releases
+export K8S_VERSION_CURRENT=$(kc version --short | awk '/^Server/{print substr($3,2)}')<br>
+export K8S_VERSION_LATEST=$(curl -sL https://dl.k8s.io/release/stable-${K8S_VERSION_CURRENT%.*}.txt)
+
+## otherwise
+export K8S_VERSION_MAJOR=1<br>
+export K8S_VERSION_LATEST=$(curl -sL https://dl.k8s.io/release/stable-${K8S_VERSION_MAJOR}.txt)
+
+### control plane first
+kubectl drain master1 --ignore-daemonsets --delete-local-data<br>
+ssh master1 sudo apt update
+
+### when upgrading the OS
+ssh master1 bash -xs < k8s-ubuntu-update-os
+
+### otherwise
+ssh master1 bash -xs < k8s-ubuntu-update-master<br>
+kubectl uncordon master1<br>
+sleep 60<br>
+ssh master1 sudo docker image prune -af
+
+### workload plane, workers one by one
+kubectl drain worker1 --ignore-daemonsets --delete-local-data<br>
+ssh worker1 sudo apt update
+
+### when upgrading the OS
+ssh worker1 bash -xs < k8s-ubuntu-update-os
+
+### otherwise
+ssh worker1 bash -xs < k8s-ubuntu-update-worker<br>
+kubectl uncordon worker1<br>
+sleep 60<br>
+ssh worker1 sudo docker image prune -af
diff --git a/k8s-ubuntu-install b/k8s-ubuntu-install
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index 0000000..c11c1b1
--- /dev/null
+++ b/k8s-ubuntu-install
@@ -0,0 +1,10 @@
+sudo apt-get update && sudo apt-get install -y apt-transport-https curl
+curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
+cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
+deb https://apt.kubernetes.io/ kubernetes-xenial main
+EOF
+sudo apt-get update
+sudo apt-get install -y kube{let,adm,ctl} docker.io
+sudo apt-mark hold kube{let,adm,ctl,rnetes-cni}
+sudo systemctl enable --now docker
+sudo gpasswd -a ubuntu docker
diff --git a/k8s-ubuntu-update-master b/k8s-ubuntu-update-master
new file mode 100644
index 0000000..f304fdb
--- /dev/null
+++ b/k8s-ubuntu-update-master
@@ -0,0 +1,14 @@
+if [ ${K8S_VERSION_CURRENT:-v0.0.0} = ${K8S_VERSION_LATEST#v} ];
+	then
+		echo nothing to do
+		exit 0
+fi
+
+sudo apt install -y kubeadm=${K8S_VERSION_LATEST#v}-00
+sudo kubeadm upgrade apply -y ${K8S_VERSION_LATEST}
+sudo apt install -y kube{let,ctl}=${K8S_VERSION_LATEST#v}-00
+sudo apt autoremove -y
+sudo apt autoclean
+sudo journalctl --vacuum-time=3d
+#sudo docker image prune -af
+
diff --git a/k8s-ubuntu-update-os b/k8s-ubuntu-update-os
new file mode 100644
index 0000000..8edef0f
--- /dev/null
+++ b/k8s-ubuntu-update-os
@@ -0,0 +1,5 @@
+sudo apt-mark hold kube{adm,let,ctl,rnetes-cni}
+sudo apt upgrade -y
+sudo apt-mark unhold kube{adm,let,ctl,rnetes-cni}
+sudo shutdown -r now
+
diff --git a/k8s-ubuntu-update-worker b/k8s-ubuntu-update-worker
new file mode 100644
index 0000000..68e6654
--- /dev/null
+++ b/k8s-ubuntu-update-worker
@@ -0,0 +1,13 @@
+if [ ${K8S_VERSION_CURRENT:-v0.0.0} = ${K8S_VERSION_LATEST#v} ];
+	then
+		echo nothing to do
+		exit 0
+fi
+
+sudo apt install -y kubeadm=${K8S_VERSION_LATEST#v}-00
+sudo kubeadm upgrade node
+sudo apt install -y kube{let,ctl}=${K8S_VERSION_LATEST#v}-00
+sudo apt autoremove -y
+sudo apt autoclean
+sudo journalctl --vacuum-time=3d
+#sudo docker image prune -af