installer-prep

#!/bin/bash
#
# This script checks the operating system, architecture, bit type, and other factors to
# determine if the system is compatible with NadekoBot. If the system is supported, it
# will download and execute the main installer.
#
########################################################################################
####[ Exported and Global Variables ]###################################################


# Refer to the 'README' note at the beginning of 'linuxAIO' for more information.
readonly C_CURRENT_LINUXAIO_REVISION=44
readonly C_MAIN_INSTALLER="nadeko-main-installer"

## Modify output text color.
E_YELLOW="$(printf '\033[1;33m')"
E_GREEN="$(printf '\033[0;32m')"
E_BLUE="$(printf '\033[0;34m')"
E_CYAN="$(printf '\033[0;36m')"
E_RED="$(printf '\033[1;31m')"
E_NC="$(printf '\033[0m')"
E_GREY="$(printf '\033[0;90m')"
E_CLRLN="$(printf '\r\033[K')"
export E_YELLOW E_GREEN E_BLUE E_CYAN E_RED E_NC E_GREY E_CLRLN

## Short-hand colorized messages.
E_SUCCESS="${E_GREEN}==>${E_NC} "
E_WARNING="${E_YELLOW}==>${E_NC} "
E_ERROR="${E_RED}ERROR:${E_NC} "
E_INFO="${E_BLUE}==>${E_NC} "
E_NOTE="${E_CYAN}==>${E_NC} "
export E_SUCCESS E_WARNING E_ERROR E_INFO E_NOTE

export E_ROOT_DIR="$PWD"
export E_INSTALLER_PREP="$E_ROOT_DIR/installer-prep"


####[ Functions ]#######################################################################


####
# Identify the operating system, version number, architecture, bit type (32 or 64), etc.
# This information is then made available to the script, and the rest of the installer.
#
# NEW GLOBALS:
#   - E_DISTRO: Distribution name.
#   - E_VER: Distribution version.
#   - E_SVER: Distribution short version.
#   - E_ARCH: Architecture.
#   - pname: Pretty name.
#   - bits: Bit type.
detect_sys_info() {
    if [[ -f /etc/os-release ]]; then
        . /etc/os-release
        E_DISTRO="$ID"
        E_VER="$VERSION_ID"  # Version: x.x.x...
        E_SVER=${E_VER//.*/}  # Version: x
        pname="$PRETTY_NAME"
    else
        E_DISTRO=$(uname -s)
        E_VER=$(uname -r)
    fi

    case $(uname -m) in
        x86_64) bits="64"; E_ARCH="x64" ;;
        i*86)   bits="32"; E_ARCH="x86" ;;
        armv*)  bits="32"; E_ARCH="?" ;;
        *)      bits="?";  E_ARCH="?" ;;
    esac
}

####
# Download the latest version of 'linuxAIO' if $E_LINUXAIO_REVISION and
# $C_CURRENT_LINUXAIO_REVISION aren't of equal value.
linuxAIO_update() {
    echo "${E_WARNING}You are using an older version of 'linuxAIO'"
    read -rp "${E_NOTE}Press [Enter] to download the latest version"
    echo "${E_INFO}Downloading latest version of 'linuxAIO'..."

    if [[ -f linuxAIO.old ]]; then
        echo "${E_INFO}Removing existing 'linuxAIO.old'..."
        rm linuxAIO.old
    fi

    if [[ -f linuxAIO.sh ]]; then
        echo "${E_INFO}Backing up 'linuxAIO.sh' as 'linuxAIO.old'..."
        mv linuxAIO.sh linuxAIO.old
    elif [[ -f linuxAIO ]]; then
        echo "${E_INFO}Backing up 'linuxAIO' as 'linuxAIO.old'..."
        mv linuxAIO linuxAIO.old
    fi

    chmod -x linuxAIO.old

    ## Due to changes in 'linuxAIO', the existing configurations cannot be directly
    ## applied to the newest version of 'linuxAIO'. As a result, the existing
    ## configurations will instead be backed up as 'linuxAIO.old', and the end-user will
    ## have to reconfigure 'linuxAIO' manually.
    ##
    # shellcheck disable=SC2153
    #   $_LINUXAIO_REVISION and $_RAW_URL are from revision 38 and earlier. This means
    #   that the if statement doesn't need to test for $E_LINUXAIO_REVISION to check if
    #   the current version of 'linuxAIO' is revision 38 or earlier.
    if [[ $_LINUXAIO_REVISION ]] && ((_LINUXAIO_REVISION <= 38)); then
        curl -O "$_RAW_URL/linuxAIO" || {
            E_STDERR "Failed to download 'linuxAIO'"
            echo "${E_INFO}Restoring previous version of 'linuxAIO'..."
            [[ -f linuxAIO.old ]] \
                && mv linuxAIO.old linuxAIO \
                && chmod +x linuxAIO
            exit 1
        }
        sudo chmod +x linuxAIO
        echo "${E_NOTE}NOT applying existing configurations to 'linuxAIO'"
        echo "${E_SUCCESS}Successfully downloaded the newest version of 'linuxAIO'"
    ## Download the newest version of 'linuxAIO' and apply existing changes to it.
    elif [[ $E_LINUXAIO_REVISION != "$C_CURRENT_LINUXAIO_REVISION" ]]; then
        local installer_branch
        local installer_branch_found
        installer_branch=$(grep '^installer_branch=.*' linuxAIO.old)
        installer_branch_found="$?"
        local bot_install_version
        local bot_install_version_found
        bot_install_version=$(grep '^export E_BOT_INSTALL_VERSION=.*' linuxAIO.old)
        bot_install_version_found="$?"

        curl -O "$E_RAW_URL"/linuxAIO || {
            E_STDERR "Failed to download 'linuxAIO'"
            echo "${E_INFO}Restoring previous version of 'linuxAIO'..."
            [[ -f linuxAIO.old ]] \
                && mv linuxAIO.old linuxAIO \
                && chmod +x linuxAIO
            exit 1
        }
        sudo chmod +x linuxAIO

        echo "${E_INFO}Applying existing configurations to the new 'linuxAIO'..."

        [[ $installer_branch_found == 0 ]] \
            && sed -i "s/^installer_branch=.*/$installer_branch/" linuxAIO

        [[ $bot_install_version_found == 0 ]] \
            && sed -i "s/^export E_BOT_INSTALL_VERSION=.*/$bot_install_version/" linuxAIO

        echo "${E_SUCCESS}Successfully downloaded the newest version of 'linuxAIO'" \
            "and applied existing changes"
        echo "${E_NOTE}Make sure to update the variables in 'linuxAIO' that were not" \
            "automatically updated, using 'linuxAIO.old'"
    else
        echo "${E_SUCCESS}You are already using the latest version of 'linuxAIO'"
    fi

    clean_exit 0
}

####
# Provide the end-user with the option to continue, even if their system isn't
# officially supported.
unsupported() {
    local choice

    echo "${E_ERROR}Your operating system is not OFFICIALLY supported for the" \
        "installation, setup, and/or use of NadekoBot" >&2
    echo "${E_WARNING}${E_YELLOW}WARNING${E_NC}: By continuing, you accept that" \
        "unexpected behaviors may occur. If you run into any errors or problems with" \
        "the installation and use of the NadekoBot, you are on your own."
    read -rp "${E_INFO}Would you like to continue anyways? [y/N] " choice

    choice=${choice,,}
    case "$choice" in
        y|yes)
            clear -x
            execute_main_installer
            ;;
        *)
            clean_exit 0
            ;;
    esac
}

####
# Cleanly exit the installer by removing temporary files and exiting with an appropriate
# message and exit code.
#
# PARAMETERS:
#   - $1: exit_code (Required)
#   - $2: use_extra_newline (Optional, Default: false)
#       - Whether to output an extra blank line, to separate the previous output from
#         the output of this function.
#       - Acceptable values:
#           - true
#           - false
clean_exit() {
    local exit_code="$1"
    local use_extra_newline="${2:-false}"
    # Files to be removed.
    local installer_files=("installer-prep" "file-backup" "prereqs-installer"
        "nadeko-latest-installer" "nadeko-runner" "nadeko-main-installer")

    trap - EXIT
    [[ $use_extra_newline == true ]] && echo ""

    ## While we specify output for SIGHUP and SIGTERM in 'nadeko-main-installer', we do
    ## the same here because the those signals don't propagate to the parent script.
    case "$exit_code" in
        0|1) echo "" ;;
        129) echo -e "\n${E_WARNING}Hangup signal detected (SIGHUP)" ;;
        130) echo -e "\n${E_WARNING}User interrupt detected (SIGINT)" ;;
        143) echo -e "\n${E_WARNING}Termination signal detected (SIGTERM)" ;;
        *)   echo -e "\n${E_WARNING}Exiting with code: $exit_code" ;;
    esac

    echo "${E_INFO}Cleaning up..."
    cd "$E_ROOT_DIR" || E_STDERR "Failed to move working directory to '$E_ROOT_DIR'" "1"

    for file in "${installer_files[@]}"; do
        [[ -f $file ]] && rm "$file"
    done

    echo "${E_INFO}Exiting..."
    exit "$exit_code"
}

####
# Download and execute the main installer. This is one of the final actions performed by
# this script.
execute_main_installer() {
    E_DOWNLOAD_SCRIPT "$C_MAIN_INSTALLER" "true"
    ./"$C_MAIN_INSTALLER"
    clean_exit "$?"
}

###
### [ Functions To Be Exported ]
###

####
# Download the specified script and modify it's execution permissions.
#
# PARAMETERS:
#   - $1: script_name (Required)
#       - The name of the script to download.
#   - $2: script_output (Optional, Default: false)
#       - Whether to indicated that the script is being downloaded.
#       - Acceptable values:
#           - true
#           - false
E_DOWNLOAD_SCRIPT() {
    local script_name="$1"
    local script_output="${2:-false}"

    [[ $script_output == true ]] \
        && printf "%sDownloading '%s'..." "${E_INFO}" "$script_name"

    curl -O -s "$E_RAW_URL"/"$script_name"
    sudo chmod +x "$script_name"
}

####
# Output an error message, and if desired, exit the script.
#
# PARAMETERS:
#   - $1: error_message (Required)
#   - $2: exit_code (Optional, Default: "")
#       - If provided, exit with the provided value.
#   - $3: additional_message (Optional, Default: "")
#       - If provided, output an additional message.
E_STDERR() {
    local error_message="$1"
    local exit_code="${2:-}"
    local additional_message="${3:-}"

    echo "${E_ERROR}$error_message" >&2
    [[ $additional_message ]] && echo -e "$additional_message" >&2
    [[ $exit_code ]] && exit "$exit_code"
}


####[ Trapping Logic ]##################################################################


trap 'clean_exit "129" "true"' SIGHUP
trap 'clean_exit "130" "true"' SIGINT
trap 'clean_exit "143" "true"' SIGTERM
trap 'clean_exit "$?" "true"' EXIT


####[ Prepping ]########################################################################


# shellcheck disable=SC2153
#   $_LINUXAIO_REVISION is from revision 38 and earlier. $E_LINUXAIO_REVISION is used
#   for revision 39 and later.
if [[ $E_LINUXAIO_REVISION != "$C_CURRENT_LINUXAIO_REVISION" ]]; then
    # NOTE: The script will exit after the function has run.
    linuxAIO_update
fi


####[ Main ]############################################################################


clear -x

detect_sys_info
export E_DISTRO E_SVER E_VER E_ARCH
export -f E_DOWNLOAD_SCRIPT E_STDERR

echo "SYSTEM INFO
Bit Type: $bits
Architecture: $E_ARCH
Distro: ${pname:=$E_DISTRO}
Distro Version: $E_VER
"

if [[ $bits == 64 ]]; then
    if [[ $E_DISTRO == "ubuntu" ]]; then
        case "$E_VER" in
            24.04|22.04) execute_main_installer ;;
            *) unsupported ;;
        esac
    elif [[ $E_DISTRO == "debian" ]]; then
        case "$E_SVER" in
            12|11) execute_main_installer ;;
            *) unsupported ;;
        esac
    elif [[ $E_DISTRO == "linuxmint" ]]; then
        case "$E_SVER" in
            22|21) execute_main_installer ;;
            *) unsupported ;;
        esac
    else
        unsupported
    fi
else
    unsupported
fi