#!/bin/sh

# vblade-persist: this script sets up a permanent vblade instance under
#                 runit supervision

# Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
# Copyright: November 2007
# License: GPLv3 or later

VDIR=/var/lib/vblade-persist/vblades
SDIR=/usr/share/vblade-persist

usage() {
    echo "usage: vblade-persist setup SHELF SLOT NETIF SOURCE"
    echo "       vblade-persist ls"
    echo "       vblade-persist start|stop|restart|auto|noauto SHELF SLOT"
    echo "       vblade-persist start|stop|restart|auto|noauto all"
}

error() {
    echo "vblade-persist: $1" >&2
}

fatal() {
    error "$1"
    exit ${2:-'1'}
}

require_sv() {
    [ -x /usr/bin/sv ] || fatal "/usr/bin/sv not available.  Please install runit."
}

# FIXME: make this test a little more robust.
verify_vblade_persist_path() {
    [ -d "$1" ]
}

# shelf identifiers should be integers:
# FIXME: check that they're in a certain range? 
verify_shelf() {
    expr match "$1" '[0-9][0-9]*' >/dev/null 
}

# slot identifiers should be integers:
# FIXME: check that they're in a certain range? 
verify_slot() {
    expr match "$1" '[0-9][0-9]*' >/dev/null 
}

# FIXME: if there's no ip and no ifconfig, what do we do?
verify_interface() {
    if [ -x /bin/ip ] ; then
	/bin/ip link show "$1" >/dev/null
    elif [ -x /sbin/ifconfig ] ; then
	/sbin/ifconfig -s "$1" > /dev/null
    else
	error "Don't know how to test interface.  Assuming '$1' is acceptable."
	true
    fi
}

# make sure that the device is either a block device or a link to a
# block device:
verify_source() {
    [ -b `readlink -f "$1"` ]
}

setup() {
    SHELF="$1"
    SLOT="$2"
    NETIF="$3"
    SOURCE="$4"

    verify_shelf "$SHELF" || fatal "not a valid shelf: '$SHELF'"
    verify_slot "$SLOT" || fatal "not a valid shelf: '$SLOT'"
    verify_interface "$NETIF" || fatal "not a valid interface: '$NETIF'"
    verify_source "$SOURCE" || fatal "not a valid source: '$SOURCE'"

    DNAME="e$SHELF.$SLOT"
    
    mkdir "$VDIR/$DNAME" || fatal "Could not create directory '$VDIR/$DNAME'"
    mkdir "$VDIR/$DNAME/env"
    mkdir "$VDIR/$DNAME/log"
    mkdir "$VDIR/$DNAME/macs"
    
    # start it off idle (so that the admin can decide when to start):
    touch "$VDIR/$DNAME/down"

    ln -s "$SDIR/vblade-run" "$VDIR/$DNAME/run"
    ln -s "$SDIR/vblade-finish" "$VDIR/$DNAME/finish"
    ln -s "$SDIR/vblade-logrun" "$VDIR/$DNAME/log/run"

    echo "$SHELF" > "$VDIR/$DNAME/env/SHELF"
    echo "$SLOT" > "$VDIR/$DNAME/env/SLOT"
    echo "$NETIF" > "$VDIR/$DNAME/env/NETIF"
    echo "$SOURCE" > "$VDIR/$DNAME/env/SOURCE"

    # tell runit to supervise this vblade:
    ln -s "$VDIR/$DNAME" "/var/service/vblade-$DNAME" || fatal "Could not set up supervision for this vblade"
}


list() {
    
    echo -e '#shelf slot netif source auto stat'
    for dev in `ls "$VDIR"` ; do
         echo $(cat "$VDIR/$dev/env/SHELF" "$VDIR/$dev/env/SLOT" "$VDIR/$dev/env/NETIF" "$VDIR/$dev/env/SOURCE") $( [ -e "$VDIR/$dev/down" ] && echo 'no')auto $(cat "$VDIR/$dev/supervise/stat")
    done
}

svcommand() {
    require_sv
    CMD="$1"
    SVDIR="$2"
    verify_vblade_persist_path "$SVDIR" || fatal "This is not a vblade-persist path"
    sv "$CMD" "$SVDIR"
}


auto() {
    verify_vblade_persist_path "$2" || fatal "This is not a vblade-persist path"
    if [ "$1" == "auto" ] ; then
	rm -f "$2/down"
    else
	touch "$2/down"
    fi
}

autoall() {
    AUTO="$1"
    for dev in `ls "$VDIR"` ; do
	auto "$AUTO" "$VDIR/$dev"
    done
}

svall() {
    require_sv
    CMD="$1"
    for dev in `ls "$VDIR"` ; do
	svcommand "$CMD" "$VDIR/$dev"
    done
}

case "$1" in
    setup)
	setup "$2" "$3" "$4" "$5"
	;;
    l*)
	list
	;;
    start|stop|restart)
	if [ "all" == "$2" ] ; then
	    svall "$1"
	else
	    verify_shelf "$2" || fatal "Not a valid shelf: '$2'"
	    verify_slot "$3" || fatal "Not a valid slot: '$3'"
	    svcommand "$1" "$VDIR/e$2.$3"
	fi
	;;
    auto|noauto)
	if [ "all" == "$2" ] ; then
	    autoall "$1"
	else
	    verify_shelf "$2" || fatal "Not a valid shelf: '$2'"
	    verify_slot "$3" || fatal "Not a valid slot: '$3'"
	    auto "$1" "$VDIR/e$2.$3"
	fi
	;;
    *)
	usage
	exit 1
	;;
esac