wizard

#!/bin/bash

KERNEL_LOCATION=/firecracker/kernel
FILESYSTEM_LOCATION=/firecracker/fs
CONFIG_LOCATION=/firecracker/configs

download_kernel() {
    print_message "🐧️ Downloading Linux kernel binary..."
    ARCH="$(uname -m)"
    wget -O $KERNEL_LOCATION/kernel https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.5/${ARCH}/vmlinux-5.10.186
    print_message "✅ Kernel binary has downloaded and been written to $KERNEL_LOCATION/kernel"
}

# Creates the ext4 filesystem for the VM
# You can think of this similar to a Docker image - which is what we build the fs from!
create_fs() {
    print_message "💿 Preparing filesystem preparation..."
    cp $PWD/fs/rootfs.Dockerfile $FILESYSTEM_LOCATION/Dockerfile
    . $PWD/fs/fs.sh
}

install_docker() {
    print_message "🐋 Installing Docker... This might take a while as we will setup all dependencies"
    curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
    sudo add-apt-repository \
    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
    $(lsb_release -cs) \
    stable"

    sudo apt-get update
    sudo apt-get install \
        bison \
        build-essential \
        flex \
        git \
        libelf-dev \
        libncurses5-dev \
        libssl-dev -y

    sudo apt-get install \
        apt-transport-https \
        ca-certificates \
        curl \
        gnupg-agent \
        software-properties-common -y

    sudo apt-get install \
        docker-ce \
        docker-ce-cli \
        containerd.io -y
    sudo groupadd docker # this may report that the group already exists
    sudo usermod -aG docker $USER

    print_message "✅ Docker has been installed succcessfully"
}

# Generates the Firecracker configuration file
setup_cfg() {
    source $PWD/config/launch.sh
    print_message "Configuring VM with kernel path of $KERNEL_LOCATION/kernel & $FILESYSTEM_LOCATION/alpine-base-root.ext4"
    gen_config $FILESYSTEM_LOCATION $KERNEL_LOCATION
    print_message "✅ Configuration JSON written to $CONFIG_LOCATION/alpine-config.json"
}

# Puts Firecracker on path
install_fc() {
    print_message "🔥 Beginning Firecracker installation"
    source $PWD/installer/install_fc.sh
    install
    print_message "✅ Firecracker successfully installed onto your PATH (/usr/bin/firecracker)"
}

run_fc() {
    print_message "🔥 Preparing to run Firecracker..."
    print_message "If this step fails, then just remove the socket and re-run..."
    firecracker --no-api --config-file $CONFIG_LOCATION/alpine-config.json 
    print_message "✅ Firecracker running!"
}

display_menu() {
    echo "🧙🔥 Firecracker Setup Wizard"
    echo ""
    echo "1) Download Linux kernel binary"
    echo "2) Install Firecracker"
    echo "3) Install Docker"
    echo "4) Setup Firecracker filesystem"
    echo "5) Setup Firecracker config JSON"
    echo "6) Run Firecracker"
    echo "7) ✨ Setup everything"
    echo "8) Exit"
}

print_message() {
    local message=$1
    local len=${#message}
    local dashes=$(printf '%*s' "$len" | tr ' ' '-')

    echo "$dashes"
    echo "$message"
    echo "$dashes"
}

setup_everything() {
    print_message "EXPERIMENTAL: Automating the entire setup process!"
    download_kernel
    install_fc
    install_docker
    create_fs
    setup_cfg
    print_message "✅ Setup complete - You may now run Firecracker from the wizard menu"
}

check_root() {
    if [ "$(id -u)" != "0" ]; then
        print_message "👋 This script must be run as root!"
        exit 1
    fi
}

clear
# sudo only for this script!
check_root

# pre-gen the necessary directories
print_message "⚠️ Creating the necessary directories underneath /firecracker/*"
mkdir -p /firecracker/{kernel,fs,configs,releases}

# USER needs r/w privleges for /dev/kvm
print_message "⚠️ Installing the acl package before we begin so we can set permissions for /dev/kvm"
sudo apt-get install -y acl
sudo setfacl -m u:${USER}:rw /dev/kvm

while true; do
    display_menu
    read -p "Pick a number ➡️ " choice
    case $choice in
        1) download_kernel ;;
        2) install_fc ;;
        3) install_docker ;;
        4) create_fs ;;
        5) setup_cfg ;;
        6) run_fc ;;
        7) setup_everything ;;
        8) break ;;
        *) echo "Invalid option, please try again." ;;
    esac
done