# $2 = the sub-host to start or stop
# $3... = the optional chroot-ed command (/startup by default)
+set -x
+
SCRIPT=$0
CMD=$1
NAME=$2
[ -z "$NAME" ] && usage
-: ${ATTIC=/opt/srv}
-: ${BRIDGE=srv_br}
-: ${TARGET=/srv/$NAME}
-: ${LOWER=$ATTIC/daedalus.fs}
-: ${IMAGE=$ATTIC/$NAME/$NAME.img}
-: ${UPPER=$ATTIC/$NAME/root}
-: ${WORK=$ATTIC/$NAME/work}
-: ${MOUNT=$ATTIC/$NAME/mnt}
+: ${SUBHOST=/opt/subhost}
+: ${OSROOT=}
+: ${TOP=$SUBHOST/$NAME}
+: ${TARGET=$TOP/live}
+: ${IMAGE=$TOP/$NAME.img}
+: ${UPPER=$TOP/root}
+: ${WORK=$TOP/work}
+: ${MOUNT=$TOP/mnt}
: ${NSNAME=$NAME}
-: ${NETH=1}
+: ${BRIDGES=homenet}
+: ${CONFIG=$TOP/config}
+
+[ -e "$CONFIG" ] && . "$CONFIG"
+
+cd "$SUBHOST" || exit 1
+# Create a simple overlay subhost without its own image file
create_subhost() {
mkdir -p $TARGET $MOUNT $UPPER $WORK
+ [ -d "$OSROOT" ] || OSROOT=$SUBHOST/daedalus/root
+ [ -e $CONFIG ] || cat <<EOF > "$CONFIG"
+# Subhost $NAME is an autogenerated overlay subhost with shared filesystem
+OSROOT="$OSROOT"
+BRIDGES="$BRIDGES"
+EOF
}
-setup_network() {
- if [ -n "$BRIDGE" ] ; then
- brctl show $BRIDGE >& /dev/null || brctl addbr $BRIDGE
- fi
+# generate a mac for given $1 (interface) using the last 5 characters
+macaddr() {
+ local M="$(xxd -p <<< "${1:$(( ${#1} - 5)):5}")66666666"
+ echo "0a:${M:0:2}:${M:2:2}:${M:4:2}:${M:6:2}:${M:8:2}"
+}
+# setup the subhost network namespace and link up the host side
+setup_network() {
E=0
ip netns add $NSNAME
- for I in $(eval echo "{1..$NETH}") ; do
+ for BRIDGE in ${BRIDGES[@]} ; do
+ brctl show $BRIDGE >& /dev/null || brctl addbr $BRIDGE
IF=$NAME$E
- ip link add $IF type veth peer name eth$E netns $NSNAME
+ MAC=$(macaddr $IF)
+ ip link add $IF type veth peer name eth$E address $MAC netns $NSNAME
ip link set $IF up
[ -n "$BRIDGE" ] && brctl addif $BRIDGE $IF
E=$((E+1))
done
}
+# check if $1 is mounted
+is_mounted() {
+ grep -qE "^[^ ]+ $1 " /proc/mounts
+}
+
+# Setup or re-setup the subhost filesystem
setup_rootfs() {
- if [ -e "$IMAGE" ] ; then
- mount $IMAGE $MOUNT || exit 1
- LOWER=$MOUNT/root
- WORK=$MOUNT/work
+ if is_mounted $TARGET ; then
+ mount -oremount $TARGET
+ else
+ if [ -f "$IMAGE" ] ; then
+ # The subhost has an image file with /root and /work in it
+ is_mounted $MOUNT || mount $IMAGE $MOUNT || exit 1
+ UPPER=$MOUNT/root
+ WORK=$MOUNT/work
+ fi
+ if [ -z "$OSROOT" ] ; then
+ # No overlay
+ mount --rbind $UPPER $TARGET
+ else
+ # overlay of $UPPER (+$WORK) over $OSROOT onto $TARGET
+ mount -t overlay $NAME \
+ -olowerdir=$OSROOT,upperdir=$UPPER,workdir=$WORK \
+ $TARGET
+ fi
fi
- mount -t overlay $NAME -olowerdir=$LOWER,upperdir=$UPPER,workdir=$WORK \
- $TARGET
}
case "$CMD" in
start)
- cd "$ATTIC" || exit 1
[ -e "/run/netns/$NSNAME" ] || setup_network
[ -d "$MOUNT" ] || create_subhost
- grep -q "^$NAME $TARGET overlay" /proc/mounts || setup_rootfs
+ setup_rootfs
START=/bin/bash
[ -x $TARGET/startup ] && START=/startup
exec ip netns exec $NSNAME unshare \