X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;ds=sidebyside;f=control;h=f5831a267f8842a3d1090dece847d4d2501648c4;hb=e0808ddd112116c36fc3fceb65bea8589dff5647;hp=28a4d2c0d99d9fb2653b4c49d8e1d78d4100595a;hpb=90c8587c002a1f8dd0fb8213534cc84f5dddbea8;p=rrq%2Fsubhost.git

diff --git a/control b/control
index 28a4d2c..f5831a2 100755
--- a/control
+++ b/control
@@ -6,6 +6,8 @@
 # $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
@@ -18,59 +20,102 @@ usage() {
 
 [ -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=lan_br}
+: ${CONFIG=$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/chimaera/base
+    [ -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 $BRIDGE
-    fi
+# map a string into a hexadecimal number with 10-digits by folding the given string into 9-digit ascii-code numbers and adding them
+hexfoldsum() {
+    local V
+    V="$(b2sum -l 40 <<< "$1" | sed 's/\(..\)/\1:/g')"
+    echo "02:${V:0:14}"
+}
 
+# Generate a mac address for given interface by passing hostname,
+# subhost name and interface through 40-bit b2sum and with 02: prefix.
+macaddr() {
+    local V="$(b2sum -l 40 <<< "$(hostname)$NAME$1" | sed 's/\(..\)/\1:/g')"
+    echo "02:${V:0:14}"
+}
+
+# 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 $TARGET
+    else
+	if [ -e "$IMAGE" ] ; then
+	    # $IMAGE is either an image file or a link to a partition,
+	    # 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 $NSNAME unshare \
 	     --fork --pid --mount-proc --kill-child \
 	     --uts --ipc --mount --cgroup \
-	     "--root=$TARGET" $START
+	     chroot $TARGET $START
 	;;
     stop)
 	umount $TARGET