lkr

#!/bin/bash
set -e
echo "𝖫𝖪𝖱 - 𝖫𝖮𝖢𝖠𝖫 𝖪𝖴𝖡𝖤𝖱𝖭𝖤𝖳𝖤𝖲 𝖱𝖴𝖭𝖭𝖤𝖱"
usage="Run Local Kubernetes cluster.\n\n\tFind more information at https://github.com/nicoloboschi/lkr\n\nCommands:\n"
usage+="\tstart\tStart the cluster and set as current context in your kubectl configuration.\n"
usage+="\tstop\tStop the cluster.\n"
usage+="\trestart\tStop and restart the cluster and set as current context in your kubectl configuration.\n"
usage+="\tstatus\tCheck if the cluster is running or not.\n"
usage+="\tlogs\tShow cluster logs.\n"
usage+="\tset\tConfigure the cluster in your kubectl configuration.\n"
usage+="\tuse\tConfigure the cluster in your kubectl configuration as current context.\n"
usage+="\tload\tLoad a local docker image into the cluster's node.\n"
usage+="\tlist\tList all docker images available into the cluster's node.\n"
usage+="\nShortcuts:\n"
usage+="\t9\tStarts k9s for the cluster.\n"
usage+="\tk\tKubectl command referred to the local cluster.\n"


trap "exit" INT TERM



if [ "$#" -eq 0 ]; then
    printf "$usage"
    exit 1
fi



#container_engine=podman
container_engine=docker
container_name=lkr
docker_image=rancher/k3s:v1.25.3-k3s1
workdir=/tmp/lkr

LKR_VERBOSE=${LKR_VERBOSE:-"false"}

lkr_log() {
    echo "$@"
}
lkr_logv() {
    if [ "$LKR_VERBOSE" == "true" ]; then
        echo "$@"
    fi
}

with_progress_bar() {
    ("$@") & 
    pid=$!
    i=1
    sp="/-\|"
    echo -n ' '

    jobs="NaN"
    while [ $jobs != "0" ]; do
        jobs=$(jobs | grep Running | wc -l)
        printf "\b${sp:i++%${#sp}:1}"
        printf "\033[0K\r"
        sleep 0.1
    done
}

with_retries() {
    for i in {1..5}; do "$@" 2>/dev/null && break || sleep 1; done
}

cleanup_docker() {
    lkr_logv "Cleaning up docker."
    docker volume prune -f >/dev/null 2>&1 || true
    docker network prune -f >/dev/null 2>&1 || true   
}


start() {
    cleanup_docker
    mkdir -p $workdir
    mkdir -p $workdir/containers
    lkr_log "Starting the cluster."
    ($container_engine run --rm -d \
        --name $container_name \
        -v /sys/fs/cgroup:/sys/fs/cgroup:rw \
        -v $workdir/containers:/containers \
        --cgroupns=host \
        --privileged \
        -p 6443:6443 \
        $docker_image server --tls-san=localhost --disable=traefik --service-node-port-range=30000-32767) > /dev/null
    

    with_retries $container_engine cp $container_name:/etc/rancher/k3s/k3s.yaml $workdir/kubeconfig
    with_retries KUBECONFIG=$workdir/kubeconfig kubectl wait --for=condition=Ready nodes --all --timeout=600s
    lkr_log "Cluster ready, configuring 'ns' namespace."
    in_context kubectl create namespace ns
    in_context kubectl config set-context --current --namespace=ns > /dev/null
    lkr_log "Cluster configured."
    with_progress_bar set_in_kube_config
    with_progress_bar use_in_kube_config
}
stop() {
    $container_engine rm -f $container_name >/dev/null
    rm -rf $workdir
}

in_context() {
    KUBECONFIG=$workdir/kubeconfig "$@"
}

load() {
    lkr_log "Loading image $1"
    id=$(docker inspect $1 | jq -r '.[0].Id')
    if [ "$id" == "null" ]; then
        lkr_log "Image not found, please pull it first."
        exit 1
    fi
    filename=$(echo $id | base64)
    host_filename_done=$workdir/containers/${filename}_done
    host_filename=$workdir/containers/$filename
    if [ ! -f "$host_filename_done" ]; then
        lkr_log "Generating image tarball."
        docker save $1 > $host_filename
        touch $host_filename_done
        lkr_log "Generated."
    fi
    lkr_log "Importing image."
    $container_engine exec $container_name ctr image import /containers/$filename
    lkr_log "Imported."
}


list() {
    $container_engine exec $container_name ctr image list | awk '{print $1}' | grep -v "sha256"
}

shell() {
    $container_engine exec -it $container_name sh
}

set_in_kube_config() {
    certificate_auth_data=$(cat $workdir/kubeconfig | grep certificate-authority-data | awk -F: '{print $2}' | tr -d ' ')
    client_ca_data=$(cat $workdir/kubeconfig | grep client-certificate-data | awk -F: '{print $2}' | tr -d ' ')
    client_key_data=$(cat $workdir/kubeconfig | grep client-key-data | awk -F: '{print $2}' | tr -d ' ')

    kubectl config set-cluster lkr --server="https://127.0.0.1:6443" > /dev/null
    kubectl config set clusters.lkr.certificate-authority-data $certificate_auth_data > /dev/null
    
    kubectl config set-credentials lkr > /dev/null
    kubectl config set users.lkr.client-certificate-data $client_ca_data > /dev/null
    kubectl config set users.lkr.client-key-data $client_key_data > /dev/null
    kubectl config set-context lkr --cluster=lkr --namespace=ns --user=lkr > /dev/null
}
use_in_kube_config() {
    kubectl config use-context lkr
}

get_status() {
    output=$(($container_engine ps | grep $container_name) || echo "")
    if [ "$output" == "" ]; then
        echo "Stopped"
    else
        echo "Running"
    fi
}

if [ "$1" == "start" ]; then
    if [ "$(get_status)" == "Running" ]; then
        lkr_log "Cluster already running."
        with_progress_bar set_in_kube_config
        with_progress_bar use_in_kube_config
    else
        with_progress_bar start
    fi
elif [ "$1" == "status" ]; then
    get_status
elif [ "$1" == "restart" ]; then
    with_progress_bar stop
    with_progress_bar start
    with_progress_bar set_in_kube_config
    with_progress_bar use_in_kube_config
elif [ "$1" == "stop" ]; then
    with_progress_bar stop
elif [ "$1" == "logs" ]; then
    $container_engine logs $container_name
elif [ "$1" == "shell" ]; then
    shell
elif [ "$1" == "set" ]; then
    with_progress_bar set_in_kube_config
    with_progress_bar use_in_kube_config
elif [ "$1" == "use" ]; then
    with_progress_bar use_in_kube_config
elif [ "$1" == "load" ]; then
    shift 
    with_progress_bar load "$@"
elif [ "$1" == "list" ]; then
    with_progress_bar list
elif [ "$1" == "k" ]; then
    shift
    with_progress_bar in_context kubectl "$@"
elif [ "$1" == "9" ]; then
    shift
    in_context k9s "$@"
else
    in_context "$@"
fi