installation and uninstallation command added for installer algo (#495)

Added the consolidated steps that need to perform for installing/uninstalling of supported k8s version on supported ubuntu as variables in installer package

Signed-off-by: Mayur Das <[email protected]>

agent/installer/steps.go

@@ -0,0 +1,63 @@
+// Copyright 2021 VMware, Inc. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package installer
+
+// contains the installation and uninstallation steps for the supported os and k8s
+var (
+	DoUbuntu20_4K8s1_22 = `
+set -euo pipefail
+
+BUNDLE_PATH=${BUNDLE_PATH:-"/var/lib/byoh/bundles"}
+
+## disable swap
+swapoff -a && sed -ri '/\sswap\s/s/^#?/#/' /etc/fstab
+
+## disable firewall
+ufw disable
+
+## load kernal modules
+modprobe overlay && modprobe br_netfilter
+
+## adding os configuration
+tar -C / -xvf "$BUNDLE_PATH/conf.tar" && sysctl --system 
+
+## installing deb packages
+for pkg in cri-tools kubernetes-cni kubectl kubeadm kubelet; do
+  dpkg --install "$BUNDLE_PATH/$pkg.deb" && apt-mark hold $pkg
+done
+
+## intalling containerd
+tar -C / -xvf "$BUNDLE_PATH/containerd.tar"
+
+## starting containerd service
+systemctl daemon-reload && systemctl enable containerd && systemctl start containerd`
+
+	UndoUbuntu20_4K8s1_22 = `
+set -euo pipefail
+
+BUNDLE_PATH=${BUNDLE_PATH:-"/var/lib/byoh/bundles"}
+
+## enable swap
+swapon -a && sed -ri '/\sswap\s/s/^#?//' /etc/fstab
+
+## enable firewall
+ufw enable
+
+## remove kernal modules
+modprobe -r overlay && modprobe -r br_netfilter
+
+## removing os configuration
+tar tf "$BUNDLE_PATH/conf.tar" | xargs -n 1 echo '/' | sed 's/ //g' | xargs rm -f
+
+## removing deb packages
+for pkg in cri-tools kubernetes-cni kubectl kubeadm kubelet; do
+	dpkg --purge $pkg
+done
+
+## removing containerd configurations and cni plugins
+rm -rf /opt/cni/ && rm -rf /opt/containerd/ &&  tar tf "$BUNDLE_PATH/containerd.tar" | xargs -n 1 echo '/' | sed 's/ //g'  | grep -e '[^/]$' | xargs rm -f
+
+## disabling containerd service
+systemctl stop containerd && systemctl disable containerd && systemctl daemon-reload`
+)