#!/bin/bash

# shopt -s inherit_errexit
set -o errexit

###################################################################
## Vultr Marketplace Helper Functions

function error_detect_on()
{
    set -euo pipefail
}

function error_detect_off()
{
    set +euo pipefail
}

function enable_verbose_commands()
{
    set -x
}

function disable_verbose_commands()
{
    set +x
}

function get_metadata_item()
{
    local item_path="${1:-}"
    local item_value

    item_value="$(curl --fail --silent --header "Metadata-Token: vultr" "http://169.254.169.254/${item_path}")"

    echo "${item_value}"
}

function get_hostname()
{
    get_metadata_item "latest/meta-data/hostname"
}

function get_userdata()
{
    get_metadata_item "latest/user-data"
}

function get_sshkeys()
{
    get_metadata_item "current/ssh-keys"
}

function get_var()
{
    local var_name="${1:-}"
    local var_val
    var_val="$(get_metadata_item "v1/internal/app-${var_name}" 2>/dev/null)"

    eval "${var_name}='${var_val}'"
}

function get_ip()
{
    local ip_var="${1:-}"
    local ip_val
    ip_val="$(get_metadata_item "latest/meta-data/public-ipv4" 2>/dev/null)"

    eval "${ip_var}='${ip_val}'"
}

function wait_on_apt_lock()
{
    until ! lsof -t /var/cache/apt/archives/lock /var/lib/apt/lists/lock /var/lib/dpkg/lock >/dev/null 2>&1
    do
        echo "Waiting 3 for apt lock currently held by another process."
        sleep 3
    done
}

function apt_safe()
{
    wait_on_apt_lock
    apt install -y "$@"
}

function apt_update_safe()
{
    wait_on_apt_lock
    apt update -y
}

function apt_upgrade_safe()
{
    wait_on_apt_lock
    DEBIAN_FRONTEND=noninteractive apt upgrade -y
}

function apt_remove_safe()
{
    wait_on_apt_lock
    apt remove -y --auto-remove "$@"
}

function apt_clean_safe()
{
    wait_on_apt_lock
    apt autoremove -y

    wait_on_apt_lock
    apt autoclean -y
}

function update_and_clean_packages()
{
    # RHEL/CentOS
    if [[ -f /etc/redhat-release ]]; then
        yum update -y
        yum clean all
    # Ubuntu / Debian
    elif grep -qs "debian" /etc/os-release 2>/dev/null; then
        apt_update_safe
        apt_upgrade_safe
        apt_clean_safe
    fi
}

function set_vultr_kernel_option()
{
    # RHEL/CentOS
    if [[ -f /etc/redhat-release ]]; then
        /sbin/grubby --update-kernel=ALL --args vultr
    # Ubuntu / Debian
    elif grep -qs "debian" /etc/os-release 2>/dev/null; then
        sed -i -e "/^GRUB_CMDLINE_LINUX_DEFAULT=/ s/\"$/ vultr\"/" /etc/default/grub
        update-grub
    fi
}

function install_cloud_init()
{
    local cloud_init_exe
    cloud_init_exe="$(command -v cloud-init >/dev/null 2>&1)"
    if [[ -x "${cloud_init_exe}" ]]; then
        echo "cloud-init is already installed."
        return
    fi

	local release_version="${1:-"latest"}"
    if [[ "${release_version}" != "latest" && "${release_version}" != "nightly" ]]; then
        echo "${release_version} is an invalid release option. Allowed: latest, nightly"
        exit 255
    fi

    # Lets remove all traces of previously installed cloud-init
    # Ubuntu installs have proven problematic with their left over
    # configs for the installer in recent versions
    cleanup_cloudinit

    update_and_clean_packages

    local build_type
    local package_ext

    [[ -e /etc/os-release ]] && . /etc/os-release
    case "${ID:-}" in
    debian)
        build_type="debian"
        package_ext="deb"
        ;;
    fedora)
        build_type="rhel"
        package_ext="rpm"
        ;;
    ubuntu)
        build_type="universal"
        package_ext="deb"
        ;;
    *)
        case "${ID_LIKE:-}" in
        *rhel*)
            build_type="rhel"
            package_ext="rpm"
            ;;
        *)
            echo "Unable to determine OS. Please install from source!"
            exit 255
        esac
    esac

    local cloud_init_package="cloud-init_${build_type}_${release_version}.${package_ext}"
    wget -O "/tmp/${cloud_init_package}" "https://ewr1.vultrobjects.com/cloud_init_beta/${cloud_init_package}"

    case "${package_ext}" in
    rpm)
        yum install -y "/tmp/${cloud_init_package}"
        ;;
    deb)
        apt_safe "/tmp/${cloud_init_package}"
        ;;
    *)
        echo "Unable to determine package installation method."
        exit 255
    esac

    rm -f "/tmp/${cloud_init_package}"
}

function cleanup_cloudinit()
{
    rm -rf \
        /etc/cloud \
        /etc/systemd/system/cloud-init.target.wants/* \
        /lib/systemd/system/cloud* \
        /run/cloud-init \
        /usr/bin/cloud* \
        /usr/lib/cloud* \
        /usr/local/bin/cloud* \
        /usr/src/cloud* \
        /var/log/cloud*
}

function clean_tmp()
{
    mkdir -p /tmp
    chmod 1777 /tmp
    rm -rf /tmp/* /var/tmp/*
}

function clean_keys()
{
    rm -f /root/.ssh/authorized_keys /etc/ssh/*key*
    touch /etc/ssh/revoked_keys
    chmod 600 /etc/ssh/revoked_keys
}

function clean_logs()
{
    find /var/log -mtime -1 -type f -exec truncate -s 0 {} \;
    rm -rf \
        /var/log/*.[0-9] \
        /var/log/*.gz \
        /var/log/*.log \
        /var/log/lastlog \
        /var/log/wtmp

    : > /var/log/auth.log
}

function clean_history()
{
    history -c
    : > /root/.bash_history
    unset HISTFILE
}

function clean_mloc()
{
    /usr/bin/updatedb || true
}

function clean_random()
{
    rm -f /var/lib/systemd/random-seed
}

function clean_machine_id()
{
    [[ -e /etc/machine-id ]] && : > /etc/machine-id
    [[ -e /var/lib/dbus/machine-id ]] && : > /var/lib/dbus/machine-id
}

function clean_free_space()
{
    dd if=/dev/zero of=/zerofile || true
    sync
    rm -f /zerofile
    sync
}

function trim_ssd()
{
    fstrim / || true
}

function cleanup_marketplace_scripts()
{
    rm -f /root/*.sh
}

function disable_network_manager()
{
    ## Disable NetworkManager, replace with network-scripts
    systemctl disable --now NetworkManager
    sed -i \
        -e 's/^ONBOOT.*/ONBOOT=yes/g' \
        -e 's/^NM_CONTROLLED.*/NM_CONTROLLED=no/g' /etc/sysconfig/network-scripts/ifcfg-*
    yum install -y network-scripts
}

function clean_system()
{

    update_and_clean_packages
    set_vultr_kernel_option
    clean_tmp
    clean_keys
    clean_logs
    clean_history
    clean_random
    clean_machine_id
    clean_mloc
    clean_free_space
    trim_ssd

    cleanup_marketplace_scripts
}