add 'weave reset'

Closes #20.

README.md

@@ -363,6 +363,24 @@ One can ask a weave router to report its status with
 
     weave status
 
+To stop weave, run
+
+    weave stop
+
+Note that this leaves the local application container network intact;
+containers on the local host can continue to communicate, whereas
+communication with containers on different hosts, as well as service
+export/import, is disrupted but resumes when weave is relaunched.
+
+To stop weave and completely remove all traces of the weave network on
+the local host, run
+
+    weave reset
+
+Any running application containers will permanently lose connectivity
+with the weave network and have to be restarted in order to
+re-connect.
+
 ## Installation with Boot2Docker
 
 If you are running Docker inside the Boot2Docker VM, e.g. because you

weaver/weave

@@ -9,6 +9,7 @@ usage() {
     echo "weave hide   <ipaddr>/<subnet>"
     echo "weave status"
     echo "weave stop"
+    echo "weave reset"
     exit 1
 }
 
@@ -60,6 +61,12 @@ create_bridge() {
     ip link set dev $BRIDGE up
 }
 
+destroy_bridge() {
+    if [ -d /sys/class/net/$BRIDGE ] ; then
+        ip link del dev $BRIDGE
+    fi
+}
+
 run_iptables() {
     # -w is recent addition to iptables
     if [ -z "$CHECKED_IPTABLES_W" ] ; then
@@ -215,6 +222,13 @@ case "$COMMAND" in
         check_command_and_run conntrack conntrack -D -p udp --dport 6783 >/dev/null 2>&1 || true
         stop_masquerading
         ;;
+    reset)
+        docker kill weave >/dev/null 2>&1 || true
+        docker rm -f weave >/dev/null 2>&1 || true
+        check_command_and_run conntrack conntrack -D -p udp --dport 6783 >/dev/null 2>&1 || true
+        stop_masquerading
+        destroy_bridge
+        ;;
     *)
         echo "Unknown weave command '$COMMAND'"
         usage