alfred.sh

#!/system/bin/sh
set -u
## ========================================================================================
## alfred  : manages an ArchLinux rootfs for enable LXC usage on Android
## ========================================================================================
PROGNAME="alfred"
PROGVERS="0.0.6"
PROGCONF="/data/$PROGNAME"
PROGHELP="Usage: $PROGNAME [cmd]

Setup commands:
install <path>        # Install alfred under <path>
uninstall             # Uninstall alfred
"
PROGPATH=
PROGTREE=

## ----------------------------------------------------------------------------------------
## Environment
## ----------------------------------------------------------------------------------------
SMOUNT_BIN="/data/cloudlet/smount"
BUSYBOX_BIN="/system/bin/busybox"
BUSYBOX_APPLETS="awk basename chroot grep head rdate tar wget"
NTP_SERVER="ntp.unice.fr"
ROOTFS_IMG_SRC="http://archlinuxarm.org/os/ArchLinuxARM-armv7-latest.tar.gz"
ROOTFS_IMG_DIST="archlinux"
ROOTFS_IMG_RELEASE="latest"
ROOTFS_IMG_ARCH="armv7"
ROOTFS_IMG_NAME=
ROOTFS_IMG_PATH=
AUTO_ACCEPT=
BAD_CONFIG=
READ=
ROOTFS_INIT=$(cat <<EOF
rm -f /etc/resolv.conf
echo "nameserver 8.8.8.8" > /etc/resolv.conf
pacman -Syu --noconfirm
pacman -S --noconfirm git lxc wget
echo "Bye!"
EOF
)

## ----------------------------------------------------------------------------------------
## Main functions
## ----------------------------------------------------------------------------------------
main() {
    checkSystem
    [ $# -lt 1 ] && notfound
    local cmd=$1; shift
    case $cmd in
        help)
            echo "$PROGHELP"
            exit
            ;;
        mount|umount)
            [ 0 -lt $# ] && notfound
            checkInstall
            cmd=$cmd"Rootfs"
            $cmd
            ;;
        install|uninstall)
            [ "$cmd" = "uninstall" ] && checkInstall
            $cmd $@
            ;;
        *)
            checkInstall
            run $cmd $@
            ;;
    esac
}

install() {
    [ $# -lt 1 ] && notfound
    [ 2 -lt $# ] && notfound
    [ 1 -lt $# ] && [ "$2" = "auto-accept" ] && AUTO_ACCEPT=1
    [ "$PROGPATH" != "" ] \
        && error "FAILED! Alfred is already installed under path $PROGPATH" \
        && warn "You must REMOVE IT FIRST with 'alfred uninstall'"
        #&& fail "You must REMOVE it with 'alfred uninstall'"
    PROGPATH=$1
    [ "${PROGPATH:0:1}" != "/" ] && PROGPATH="$(pwd)/$PROGPATH"
    echo "Alfred will be INSTALLED under the path $PROGPATH"
    confirm "Are you sure? [y/N]"
    installWizard
    echo "Done!"
}

uninstall() {
    [ 1 -lt $# ] && notfound || [ 0 -lt $#  ] && [ "$1" = "auto-accept" ] && AUTO_ACCEPT=1
    echo "Alfred installation under the path $PROGPATH will be REMOVED"
    confirm "Are you sure? [y/N]"
    umountRootfs
    rm -fr $PROGPATH >/dev/null 2>&1
    rm -f $PROGCONF >/dev/null 2>&1
    echo "Done!"
}

run() {
    [ "$BAD_CONFIG" = "1" ] && fail "FAILED! Check your file configuration $PROGCONF"
    mountRootfs
    local cmd="/bin/bash"
    [ 0 -lt $# ] && cmd="$@"
    beforeRunning $cmd
    changeRoot "$cmd"
    afterRunning $cmd
}

## ----------------------------------------------------------------------------------------
## Support functions
## ----------------------------------------------------------------------------------------
warn() {
    echo $@ >&2
}

error() {
    echo $@ 1>&2
}

fail() {
    [ 0 -lt $# ] && error $@
    exit 1
}

notfound() {
    error "ERROR: command not found"
    echo "--"
    echo "$PROGHELP"
    fail
}

checkBusybox() {
    [ ! -e "/system/bin/adb" ] && return
    if ! type $BUSYBOX_BIN >/dev/null 2>&1; then
        echo "FAILED! This program needs busybox to work" 1>&2
        exit 1
    fi
    for i in $BUSYBOX_APPLETS; do
        eval "alias '$i=$BUSYBOX_BIN $i'"
    done
}

checkConfig() {
    [ -e $PROGCONF ] && . $PROGCONF
    [ "$PROGPATH" != "" ] && [ ! -e $PROGPATH ] && PROGPATH= && BAD_CONFIG=1
    for i in $PROGTREE; do
        [ ! -e "$PROGPATH/$i" ] && BAD_CONFIG=1 && break
    done
    [ "$BAD_CONFIG" = "1" ] && warn "WARN! Verify your installation under $PROGPATH"
}

checkSystem() {
    checkBusybox
    checkConfig
    [ $(date +%Y) -lt 2000 ] && rdate -s $NTP_SERVER
    [ ! -e "/etc/resolv.conf" ] && echo "nameserver 8.8.8.8" > /etc/resolv.conf
}

checkInstall() {
    [ "$PROGPATH" = "" ] && fail "FAILED! Alfred is not installed yet"
}

prompt() {
    [ 0 -lt $# ] && echo -n "$@ "
    read PROMPT
}

confirm() {
    [ "$AUTO_ACCEPT" = "1" ] && return
    prompt $@
    case $PROMPT in
      [yY][eE][sS]|[yY])
          PROMPT=1
          ;;
      *)
          fail "Cancelled."
          ;;
    esac
}

downloadFile() {
    if [ ! -e "$2" ]; then
        if ! wget -q $1 -O $2; then
            rm -f $2 >/dev/null 2>&1
            return 1
        fi
        [ ! -e "$2" ] && return 1
    fi
    return 0
}

unpackArchive() {
    if ! tar --numeric-owner -xf $1 -C $2 >/dev/null 2>&1; then
        return 1
    fi
    return 0
}

writeConfig() {
    echo "$1=\"$2\"" >> $PROGCONF
}

updateConfig() {
    [ -e "$PROGCONF" ] && rm -f $PROGCONF >/dev/null 2>&1
    touch $PROGCONF >/dev/null 2>&1
    writeConfig "PROGPATH" $PROGPATH
    writeConfig "PROGTREE" "$PROGTREE"
}

installWizard() {
    echo -n "[1/5] Creating the install directory... "
    if ! mkdir -p $PROGPATH >/dev/null 2>&1; then
        fail "KO"
    fi
    echo "ok"
    echo -n "[2/5] Donwloading the rootfs image... "
    ROOTFS_IMG_NAME="$ROOTFS_IMG_DIST-$ROOTFS_IMG_RELEASE-$ROOTFS_IMG_ARCH-rootfs.tar.gz"
    ROOTFS_IMG_PATH="$PROGPATH/$ROOTFS_IMG_NAME"
    if ! downloadFile $ROOTFS_IMG_SRC $ROOTFS_IMG_PATH; then
        fail "KO"
    fi
    echo "ok"
    echo -n "[3/5] Unpacking the rootfs image... "
    if ! unpackArchive $ROOTFS_IMG_PATH $PROGPATH; then
        fail "KO"
    fi
    PROGTREE=
    for i in $(find $PROGPATH -maxdepth 1 -type d); do
        i=$(basename $i)
        [ "$i" = "$(basename $PROGPATH)" ] && continue
        [ -z "$PROGTREE" ] && PROGTREE=$i && continue
        PROGTREE="$PROGTREE $i"
    done
    if ! updateConfig >/dev/null 2>&1; then
        fail "KO"
    fi
    echo "ok"
    echo -n "[4/5] Configuring the rootfs... "
    echo "$ROOTFS_INIT" > $PROGPATH/rootfs.init
    chmod 755 $PROGPATH/rootfs.init >/dev/null 2>&1
    if ! run "/rootfs.init" >/dev/null 2>&1; then
        fail "KO"
    fi
    rm -f $PROGPATH/rootfs.init >/dev/null 2>&1
    echo "ok"
    echo -n "[5/5] Finalizing the installation... "
    rm -f $ROOTFS_IMG_PATH >/dev/null 2>&1
    echo "ok"
}

execCmd() {
    $@ >/dev/null 2>&1
}

mountRootfs() {
    execCmd $SMOUNT_BIN / rprivate
    if ! grep -q " $PROGPATH " /proc/mounts; then
        execCmd mount -o bind $PROGPATH $PROGPATH
    fi
    for i in acct dev dev/cpuctl dev/pts proc sys sys/fs/cgroup system; do
        [ ! -d /$i ] && continue
        if grep -q " $PROGPATH/$i " /proc/mounts; then
            continue
        fi
        execCmd mkdir -p $PROGPATH/$i
        execCmd mount -o bind /$i $PROGPATH/$i
    done
    for i in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
        if ! grep -q " $PROGPATH/$i " /proc/mounts; then
            execCmd mkdir -p $PROGPATH/$i
            execCmd $BUSYBOX_BIN mount -n -t cgroup -o $i cgroup $PROGPATH/$i
        fi
    done
}

umountRootfs() {
    cgmanagerStop
    for i in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
        execCmd umount $PROGPATH/$i
    done
    for i in system sys/fs/cgroup sys proc dev/pts dev/cpuctl dev acct; do
        if ! grep -q " $PROGPATH/$i " /proc/mounts; then
            continue
        fi
        execCmd umount $PROGPATH/$i
    done
    if grep -q " $PROGPATH " /proc/mounts; then
        execCmd umount $PROGPATH
    fi
}

changeRoot() {
    local env="TERM=$TERM SHELL=/bin/bash USER=root USERNAME=root HOME=/root PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin LD_PRELOAD="
    local envBackup="TERM=$TERM SHELL=$SHELL USER=$USER HOME=$HOME PATH=$PATH LD_PRELOAD=$LD_PRELOAD"
    for i in $env; do export $i; done
    $BUSYBOX_BIN chroot $PROGPATH $@
    for i in $envBackup; do export $i; done
}

beforeRunning() {
    case $1 in
        "lxc-start") cmdLxcStartPrevent "$@" ;;
    esac
}

afterRunning() {
    case $1 in
        "lxc-create") cmdLxcCreateCallback "$@" ;;
    esac
}

cgmanagerIsRunning() {
    if [ $(changeRoot "ps -x" | grep -c cgmanager) -lt 2 ]; then
        return 1
    fi
}

cgmanagerStart() {
    if ! cgmanagerIsRunning >/dev/null 2>&1; then
        changeRoot cgmanager --daemon
    fi
}

cgmanagerStop() {
    if cgmanagerIsRunning >/dev/null 2>&1; then
        changeRoot kill $(changeRoot ps -x | grep cgmanager | head -n1 | awk '{print $1}')
    fi
}

cmdLxcStartPrevent() {
    cgmanagerStart
}

cmdLxcCreateCallback() {
    local nameFound=
    local containerName=
    local containerPath=
    for i in "$@"; do
        [ "$nameFound" = "1" ] && containerName=$i && break
        [ "$i" = "-n" ] && nameFound=1
    done
    [ -z "$containerName" ] && return
    containerPath=/var/lib/lxc/$containerName/rootfs
    [ ! -d "$PROGPATH/$containerPath" ] && return
    changeRoot chroot $containerPath passwd
}

## ----------------------------------------------------------------------------------------
## One main to rule them all...
## ----------------------------------------------------------------------------------------
main $@