also unshare ipc and utc on boot

[rrq/overlay-boot.git] / overlay-boot

diff --git a/overlay-boot b/overlay-boot
index 431263da2474e30bcd370d270aa820269f5b1393..e94620ec70746b22f14fc61373811b9ef39e8090 100755 (executable)
--- a/overlay-boot
+++ b/overlay-boot
@@ -4,10 +4,14 @@
 # is an overlay of the subhost's root and an OS root. The service
 # subhost is defined by a configuration file named on teh command line
 
+OVERLAYDIR="$(dirname $(realpath $0))"
+
 [ $(id -u) = 0 ] || exec sudo $0 $@
-. $(dirname $(realpath $0))/functions $*
+. $OVERLAYDIR/functions $*
+
 CONFIG="$1"
 [ -r "$CONFIG" ] || die "Missing configuration $CONFIG"
+
 config NAME $(basename $1 .${1##*.})
 config LOG /tmp/oly-$NAME.log
 
@@ -28,6 +32,10 @@ fi
 config BASE
 BASE="$(cd $(dirname $CONFIG); realpath $BASE)"
 
+[ -z "$BASE" ] && die "BASE is unset; bogus $CONFIG ?"
+[ -d "$BASE" ] || die "$BASE is not a directory; bogus $CONFIG ?"
+cd "$BASE" || die "$BASE is inaccessible"
+
 config LIVE "$BASE/live"
 config UPPER "$BASE/root"
 config WORK "$BASE/work"
@@ -36,28 +44,45 @@ config CABLES ""
 config START "networking ssh"
 config SUBSHELL /bin/sh
 
-# Setup virtual cabling and subhost's /etc/network/interfaces
+# Setup virtual cabling
 setup_veth_cables $NAME $CABLES
 
 # Set up the mount for this subhost, including a new tmpfs on its /run
+# and a default $UPPER/etc/network/interfaces if needed
 echo setup_overlay "$NAME" "$LIVE" "$LOWER" "$UPPER" "$WORK"
 setup_overlay "$NAME" "$LIVE" "$LOWER" "$UPPER" "$WORK"
 
 exithandler() {
     ip netns del $NAME
-    umount -R "$LIVE"
+    [ "$LOWER" != "$LIVE" ] && umount -R "$LIVE"
+    [ -f "${UPPER%% *}" ] && [ -x "${UPPER%% *}" ] && \
+       env ACTION=teardown $UPPER
 }
 trap "exithandler" 0
 
-CMD="unshare -fp --mount-proc ip netns exec $NAME chroot $LIVE /bin/sh"
+CMD="unshare -fp --mount-proc -i -u ip netns exec $NAME chroot $LIVE /bin/sh"
 echo "$CMD"
 
+config RAM_SIZE 50M
+
 cat <<EOF | $CMD
 set -x
 mount -t proc proc /proc
 mount -t devpts devpts /dev/pts
 mount -t sysfs sysfs /sys
+if [ "$RAM_SIZE" != "none" ] && ! grep -q '/run tmpfs' /proc/mounts ; then
+    mount -t tmpfs -osize=$RAM_SIZE,mode=755 tmpfs /run
+fi
 for srv in $START ; do service \$srv start ; done
+dummy_service() {
+    [ \$# -gt 3 ] && return 0
+    echo "Starting dummy service" >&2
+    set +x
+    [ -p /run/dummy_service ] || mkfifo /run/dummy_service
+    ( printf dummy_service > /proc/self/comm ; read X < /run/dummy_service ) &
+    set -x
+}
+dummy_service /proc/*/comm
 exec /.reaper $NAME
 EOF
 echo "EXITED $CMD"