try the BIOS UUID

weave

@@ -18,8 +18,6 @@ IMAGE_VERSION=${WEAVE_VERSION:-$IMAGE_VERSION}
 MIN_DOCKER_VERSION=1.6.0
 
 # These are needed for remote execs, hence we introduce them here
-MACHINE_ID1=/etc/machine-id
-MACHINE_ID2=/var/lib/dbus/machine-id
 DOCKERHUB_USER=${DOCKERHUB_USER:-weaveworks}
 BASE_EXEC_IMAGE=$DOCKERHUB_USER/weaveexec
 EXEC_IMAGE=$BASE_EXEC_IMAGE:$IMAGE_VERSION
@@ -113,7 +111,7 @@ docker_sock_options() {
 exec_remote() {
     docker $DOCKER_CLIENT_ARGS run --rm --privileged --net=host \
         $(docker_sock_options) \
-        -v /proc:/hostproc -v $MACHINE_ID1:$MACHINE_ID1 -v $MACHINE_ID2:$MACHINE_ID2 \
+        -v /proc:/hostproc \
         -e PROCFS=/hostproc \
         -e DOCKERHUB_USER="$DOCKERHUB_USER" \
         -e WEAVE_VERSION \
@@ -342,8 +340,6 @@ PLUGIN_IMAGE=$BASE_PLUGIN_IMAGE:$IMAGE_VERSION
 PLUGIN_CONTAINER_NAME=weaveplugin
 
 PROCFS=${PROCFS:-/proc}
-[ -z "$MACHINE_ID" -a -f $MACHINE_ID1 ] && MACHINE_ID=$(cat $MACHINE_ID1 2>/dev/null) || true
-[ -z "$MACHINE_ID" -a -f $MACHINE_ID2 ] && MACHINE_ID=$(cat $MACHINE_ID2 2>/dev/null) || true
 DOCKER_BRIDGE=${DOCKER_BRIDGE:-docker0}
 CONTAINER_NAME=${WEAVE_CONTAINER_NAME:-weave}
 BRIDGE=weave
@@ -1512,14 +1508,12 @@ launch_router() {
     enforce_docker_bridge_addr_assign_type
     create_bridge
     docker_bridge_ip
-    # Derive the router name from the machine id, if present, since
-    # that is stable across reboots. Otherwise set it to the bridge
-    # MAC since at least that is stable across router re-launches.
-    if [ -n "$MACHINE_ID" ] ; then
-        # first 6 bytes of $MACHINE_ID (which is 16 bytes, represented
-        # as a 32-digit hex string), in MAC notation
-        PEERNAME=$(echo "$MACHINE_ID" | sed 's/\(.\{2\}\)/\1:/g' | cut -c1-17)
-    else
+    # Derive the router name from the BIOS UUID, if present, since
+    # that is stable across reboots, unique across VMs (unlike, say,
+    # /etc/machine-id, which is often identical on VMs created from
+    # cloned filesystems).  Otherwise set it to the bridge MAC since
+    # at least that is stable across router re-launches.
+    if ! PEERNAME=$(cat /sys/class/dmi/id/product_uuid 2>/dev/null | sha256sum | sed 's/\(.\{2\}\)/\1:/g' | cut -c1-17) ; then
         PEERNAME=$(cat /sys/class/net/$BRIDGE/address)
     fi
     # backward compatibility...