revise installation of e/n/i file

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

diff --git a/overlay-boot b/overlay-boot
index 239ae1cc7228d4c4a1b06a86b5b44a0e4e336516..75939fe97a2b670863cabf5252297f59e1bd10c7 100755 (executable)
--- a/overlay-boot
+++ b/overlay-boot
@@ -4,9 +4,10 @@
 # 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
 
-[ $(id -u) = 0 ] || exec sudo $0 $@
+OVERLAYDIR="$(realpath $(dirname $0))"
 
-. $(dirname $(realpath $0))/functions
+[ $(id -u) = 0 ] || exec sudo $0 $@
+. $(dirname $(realpath $0))/functions $*
 
 CONFIG="$1"
 [ -r "$CONFIG" ] || die "Missing configuration $CONFIG"
@@ -19,13 +20,22 @@ if [ -z "$UNSHARED" ] ; then
     #
     # Create the network namespace for the subhost, then trigger
     # detached re-run with unshared mount namespace
-    [ -r /run/netns/$NAME ] || ip netns add $NAME
+    [ -r /run/netns/$NAME ] || {
+       ip netns add $NAME
+       ip netns exec $NAME ip link set lo up
+    }
     exec env UNSHARED=yes unshare -m $0 $@ > $LOG 2>&1 &
     echo "Logging to $LOG" >&2
     exit 0
 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"
@@ -33,28 +43,46 @@ config LOWER "/"
 config CABLES ""
 config START "networking ssh"
 config SUBSHELL /bin/sh
-config STOP ""
 
-# 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 $LIVE /bin/sh"
 echo "$CMD"
+
+config RAM_SIZE 50M
+
 cat <<EOF | $CMD
 set -x
-mount --bind $UPPER/run /run
+mount -t proc proc /proc
+mount -t devpts devpts /dev/pts
+mount -t sysfs sysfs /sys
+if [ "$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 $CMD"
-#echo "$STOP" | ip netns exec $NAME chroot $LIVE $SUBSHELL