junest/bin/junest

#!/usr/bin/env bash
#
# This file is part of JuNest (https://github.com/fsquillace/junest).
#

set -e

# JUNEST_BASE can be overridden for testing purposes.
# There is no need for doing it for normal usage.
JUNEST_BASE="${JUNEST_BASE:-$(readlink -f $(dirname $(readlink -f "$0"))/..)}"

source "${JUNEST_BASE}/lib/utils/utils.sh"
source "${JUNEST_BASE}/lib/core/common.sh"

source "${JUNEST_BASE}/lib/core/build.sh"
source "${JUNEST_BASE}/lib/core/chroot.sh"
source "${JUNEST_BASE}/lib/core/namespace.sh"
source "${JUNEST_BASE}/lib/core/proot.sh"
source "${JUNEST_BASE}/lib/core/setup.sh"


###################################
### General functions           ###
###################################

usage() {
    echo -e "$NAME (v$(cat $JUNEST_BASE/VERSION)): $DESCRIPTION"
    echo
    echo -e "Usage: $CMD [options] [--] [command]"
    echo
    echo -e "Setup options:"
    echo -e "-i, --setup-from-file <image>  Setup the $NAME image in ${JUNEST_HOME}"
    echo -e "-a, --arch <arch>              $NAME architecture to download (x86_64, x86, arm)"
    echo -e "                               Defaults to the host architecture ($ARCH)"
    echo -e "-d, --delete                   Delete $NAME from ${JUNEST_HOME}"
    echo
    echo -e "Access options:"
    echo -e "-f, --fakeroot                 Run $NAME with fakeroot privileges"
    echo -e "-g, --groot                    Run $NAME with root privileges via GRoot"
    echo -e "-r, --root                     Run $NAME with root privileges via classic chroot"
    echo -e "-u, --namespace                Use Linux Namespace (with GRoot) instead of PRoot"
    echo -e "-p, --backend-args <args>      Arguments for backend program (PRoot or GRoot)"
    echo -e "                               ($CMD -p \"--help\" to check out the PRoot options"
    echo -e "                                $CMD -g -p \"--help\" to check out the GRoot options"
    echo -e "                                $CMD -r -p \"--help\" to check out the chroot options)"
    echo
    echo -e "Building options:"
    echo -e "-b, --build-image              Build a $NAME image (must run in ArchLinux)"
    echo -e "-n, --disable-validation       Disable the $NAME image validation"
    echo
    echo -e "General options:"
    echo -e "-h, --help                     Show this help message"
    echo -e "-V, --version                  Show the $NAME version"
}

version() {
    echo -e "$NAME $(cat $JUNEST_BASE/VERSION)"
}

check_cli(){
    if $OPT_BUILD_IMAGE
    then
        if $OPT_DELETE || $OPT_HELP || $OPT_VERSION || $OPT_SETUP_FROM_FILE || \
            $OPT_FAKEROOT || $OPT_ROOT
        then
            die "The build image option must be used exclusively"
        fi
    fi
    if $OPT_DISABLE_VALIDATION
    then
        if $OPT_DELETE || $OPT_HELP || $OPT_VERSION || $OPT_SETUP_FROM_FILE || \
            $OPT_FAKEROOT || $OPT_ROOT
        then
            die "The disable validation option must be used with the build image option only"
        fi
    fi
    if $OPT_DELETE
    then
        if $OPT_BUILD_IMAGE || $OPT_HELP || $OPT_VERSION || $OPT_SETUP_FROM_FILE || \
            $OPT_FAKEROOT || $OPT_ROOT || $OPT_DISABLE_VALIDATION
        then
            die "The $NAME delete option must be used exclusively"
        fi
    fi
    if $OPT_HELP
    then
        if $OPT_BUILD_IMAGE || $OPT_DELETE || $OPT_VERSION || $OPT_SETUP_FROM_FILE || \
            $OPT_FAKEROOT || $OPT_ROOT || $OPT_DISABLE_VALIDATION
        then
            die "The $NAME help option must be used exclusively"
        fi
    fi
    if $OPT_VERSION
    then
        if $OPT_BUILD_IMAGE || $OPT_DELETE || $OPT_HELP || $OPT_SETUP_FROM_FILE || \
            $OPT_FAKEROOT || $OPT_ROOT || $OPT_DISABLE_VALIDATION
        then
            die "The $NAME version option must be used exclusively"
        fi
    fi
    if $OPT_FAKEROOT && $OPT_ROOT
    then
        die "You must access to $NAME with either fakeroot or root permissions"
    fi
    if $OPT_BACKEND_ARGS || $OPT_ARCH
    then
        if $OPT_BUILD_IMAGE || $OPT_DELETE || $OPT_HELP || \
            $OPT_ROOT || $OPT_VERSION || $OPT_DISABLE_VALIDATION
        then
            die "Invalid syntax: Proot and arch args are not allowed with the other options"
        fi
    fi
    if [ "$ARGS" != "" ]
    then
        if $OPT_BUILD_IMAGE || $OPT_DELETE || $OPT_HELP || $OPT_SETUP_FROM_FILE || \
            $OPT_VERSION || $OPT_DISABLE_VALIDATION
        then
            die "No arguments are needed. For the CLI syntax run: $CMD --help"
        fi
    fi

    return 0
}


function parse_arguments(){
    OPT_SETUP_FROM_FILE=false
    IMAGE_FILE=""
    OPT_FAKEROOT=false
    OPT_ROOT=false
    OPT_GROOT=false
    OPT_USER_NAMESPACE=false
    OPT_BACKEND_ARGS=false
    BACKEND_ARGS=""
    OPT_ARCH=false
    ARCH_ARG=""
    OPT_BUILD_IMAGE=false
    OPT_DISABLE_VALIDATION=false
    CHECK_ARG=""
    OPT_DELETE=false
    OPT_HELP=false
    OPT_VERSION=false
    for opt in "$@"
    do
        case "$1" in
            -i|--setup-from-file) OPT_SETUP_FROM_FILE=true ; shift ; IMAGE_FILE=$1 ; shift ;;
            -f|--fakeroot) OPT_FAKEROOT=true ; shift ;;
            -r|--root) OPT_ROOT=true ; shift ;;
            -g|--groot) OPT_GROOT=true ; shift ;;
            -u|--namespace) OPT_USER_NAMESPACE=true ; shift ;;
            -p|--backend-args) OPT_BACKEND_ARGS=true ; shift ; BACKEND_ARGS=$1; shift ;;
            -a|--arch) OPT_ARCH=true ; shift ; ARCH_ARG=$1; shift ;;
            -b|--build-image) OPT_BUILD_IMAGE=true ; shift ;;
            -n|--disable-validation) OPT_DISABLE_VALIDATION=true ; shift ;;
            -d|--delete) OPT_DELETE=true ; shift ;;
            -h|--help) OPT_HELP=true ; shift ;;
            -V|--version) OPT_VERSION=true ; shift ;;
            --) shift ; break ;;
            -*) die "Invalid option $1" ;;
            *) break ;;
        esac
    done

    ARGS=()
    for arg in "$@"
    do
        ARGS+=("$arg")
    done
}

function execute_operation(){
    $OPT_HELP && usage && return
    $OPT_VERSION && version && return

    if $OPT_BUILD_IMAGE; then
        build_image_env $OPT_DISABLE_VALIDATION
        return
    elif $OPT_DELETE; then
        delete_env
        return
    fi

    if ! is_env_installed
    then
        if $OPT_SETUP_FROM_FILE; then
            setup_env_from_file $IMAGE_FILE
        else
            setup_env $ARCH_ARG
            unset ARCH_ARG
        fi
    elif $OPT_SETUP_FROM_FILE; then
        die "Error: The image cannot be installed since $JUNEST_HOME is not empty."
    fi

    [ -z "${ARCH_ARG}" ] || \
        die "The option --arch cannot be specified since JuNest has already been downloaded in $JUNEST_HOME"

    local run_env
    if $OPT_USER_NAMESPACE; then
        run_env=run_env_with_namespace
    elif $OPT_FAKEROOT; then
        run_env=run_env_as_fakeroot
    elif $OPT_ROOT; then
        run_env=run_env_as_chroot
    elif $OPT_GROOT; then
        run_env=run_env_as_groot
    else
        run_env=run_env_as_user
    fi

    $run_env "${BACKEND_ARGS}" "${ARGS[@]}"

}

function main() {
    parse_arguments "$@"
    check_cli
    execute_operation
}

main "$@"
# vim: set ts=4 sw=4 noet: