k8sctl

#!/usr/bin/env bash
set -eu

#-------------------global setting------------------
NODES=2
# choose the version in https://kubernetes.io/releases/#release-history
K8S_VER=$(curl -Ls https://dl.k8s.io/release/stable.txt | awk -F "v" '{print $2}')
echo "[${1:-Welcome to}] k8s cluster, version: $K8S_VER"
#---------------------------------------------------

cluster_cmd(){
    local COMMAND=$1 # start/stop/restart/delete
    for INSTANCE in $(multipass list | grep k8s- | awk '{print $1}');do
        multipass $COMMAND $INSTANCE &
    done
    wait
}

ps1() {
    # pretty prompt with color
	BLACK="\033[0;30m"
	BLUE="\033[0;34m"
	GREEN="\033[0;32m"
	GREY="\033[0;90m"
	CYAN="\033[0;36m"
	RED="\033[0;31m"
	PURPLE="\033[0;35m"
	BROWN="\033[0;33m"
	WHITE="\033[0;37m"
	BOLD="\033[1m"
	COLOR_RESET="\033[0m"
    echo -ne "\n$GREEN ===> $COLOR_RESET"
}

echo_cmd() {
    echo "$(ps1)$@"
}

do_cmd() {
    echo_cmd $@
    "$@"
}

prepare() {
    sed 's/@K8S_VER@/'$K8S_VER'/' templates/cloud-init.yaml > cloud-init.yaml
    NET_OPT=""
    if [ "${USE_BRIDGE:-}" == "true" ];then
        NET_OPT="--bridged"
    fi
    export NET_OPT
}

setup_control_plane() {
    do_cmd multipass launch -vvvv --name k8s-cp --cpus 4 --memory 4G --disk 64G \
        $NET_OPT \
        --timeout $((60*10)) \
        --cloud-init cloud-init.yaml \
        --mount $(pwd):/workdir
    do_cmd multipass exec k8s-cp -- sh -c "/workdir/scripts/setup-control-plane.sh"
}

setup_node(){
    local index=$1
    do_cmd multipass launch --name k8s-node-$index --cpus 2 --memory 2G --disk 64G \
        $NET_OPT \
        --timeout $((60*10)) \
        --cloud-init cloud-init.yaml

    # token will be expired in 24 hours
    join_cp_cmd=$(multipass exec k8s-cp -- sh -c 'echo "sudo $(kubeadm token create --print-join-command) --v=5"')
    do_cmd multipass exec k8s-node-$index -- sh -c "$join_cp_cmd"
}


create_cluster(){
    setup_control_plane
    local index=0
    while [ "$index" -lt "$NODES" ]
    do
        index=$((++index))
        setup_node $index &
    done
    wait
}

check_work_nodes_ready() {
    if multipass exec k8s-cp -- kubectl get nodes | grep "NotReady"; then
        echo "These node(s) are not ready:"
        multipass exec k8s-cp -- kubectl get nodes | grep "NotReady"
    else
        echo "All nodes are ready."
    fi
}

check_all_pods_running() {
    if multipass exec k8s-cp -- kubectl get pod -A | grep -v "Running" | grep -v "NAMESPACE"; then
        echo "These pod(s) are not ready:"
        multipass exec k8s-cp -- kubectl get pod -A | grep -v "Running"
    else
        echo "All pods are running."
    fi
}

check_all_nodes_ready(){
    CONTROL_PLANE_STATUS=$(multipass list | grep k8s-cp | awk '{print $2}')
    if [ "$CONTROL_PLANE_STATUS" == "Running" ];then
        check_work_nodes_ready
        check_all_pods_running
        exit 0
    else
        echo  "ERROR: k8s-cp instance is not running."
        exit 1
    fi
}

add_node() {
    local index=${1:-}
    if [ -z "$index" ];then
        last_index=$(multipass list | grep k8s-node | sort -r | perl -ne 'print $& if $. == 1 && /(?<=-)\d+\b/')
        index=$((++last_index))
    fi
    setup_node $index
}

del_node() {
    local node=${1:-}
    if [ -z "$node" ];then
        echo "Select one node to delete:"
        select select_node in $(multipass list | grep k8s-node | awk '{print $1}' | sort)
        do
            node="$select_node"
            break
        done
    fi
    do_cmd multipass exec k8s-cp -- sh -c "kubectl drain $node --ignore-daemonsets --delete-emptydir-data"
    do_cmd multipass exec k8s-cp -- sh -c "kubectl delete node $node"
    multipass delete $node
    multipass purge
}


prepare
case ${1:-help} in
"create")
    create_cluster
    ;;
"destroy")
    cluster_cmd stop
    cluster_cmd delete
    multipass purge
    ;;
"start")
    cluster_cmd start
    ;;
"stop")
    cluster_cmd stop
    ;;
"restart")
    cluster_cmd restart
    ;;
"del")
    del_node "${2:-}"
    ;;
"add")
    add_node "${2:-}"
    ;;
"check")
    check_all_nodes_ready
    ;;
"status")
    multipass list | grep k8s-
    ;;
"login")
    multipass shell k8s-cp
    ;;
*)
    echo "usage: ./k8sctl [create | destroy | start | stop | restart | add | del | check | status | login]"
esac