Implement weave forget command

router/connection_maker.go

@@ -52,6 +52,13 @@ func (cm *ConnectionMaker) InitiateConnection(address string) {
 	}
 }
 
+func (cm *ConnectionMaker) ForgetConnection(address string) {
+	cm.actionChan <- func() bool {
+		delete(cm.cmdLineAddress, NormalisePeerAddr(address))
+		return true
+	}
+}
+
 func (cm *ConnectionMaker) ConnectionTerminated(address string) {
 	cm.actionChan <- func() bool {
 		if target, found := cm.targets[address]; found {

site/features.md

@@ -331,7 +331,15 @@ then on one of the existing hosts runs
     host# weave connect $NEW_HOST
 
 Other hosts in the weave network will automatically attempt to
-establish connections to the new host too.
+establish connections to the new host too. Conversely, it is possible
+to instruct a peer to forget a particular host that was specified
+to it via `weave launch` or `weave connect`:
+
+    host# weave forget $DECOMMISSIONED_HOST
+
+This will prevent the peer from trying to reconnect to that host once
+connectivity to it is lost, and thus can be used to administratively
+remove peers from the network.
 
 ### <a name="container-mobility"></a>Container mobility
 

weave

@@ -18,6 +18,7 @@ usage() {
     echo "weave launch     [-password <password>] [-nickname <nickname>] <peer> ..."
     echo "weave launch-dns <cidr>"
     echo "weave connect    <peer>"
+    echo "weave forget     <peer>"
     echo "weave run        [--with-dns] <cidr> <docker run args> ..."
     echo "weave start      <cidr> <container_id>"
     echo "weave attach     <cidr> <container_id>"
@@ -597,6 +598,10 @@ case "$COMMAND" in
         [ $# -eq 1 ] || usage
         http_call $CONTAINER_NAME $HTTP_PORT POST /connect -d "peer=$1"
         ;;
+    forget)
+        [ $# -eq 1 ] || usage
+        http_call $CONTAINER_NAME $HTTP_PORT POST /forget -d "peer=$1"
+        ;;
     status)
         http_call $CONTAINER_NAME $HTTP_PORT GET /status || true
         echo

weaver/main.go

@@ -176,6 +176,15 @@ func handleHttp(router *weave.Router) {
 		}
 	})
 
+	muxRouter.Methods("POST").Path("/forget").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		peer := r.FormValue("peer")
+		if addr, err := net.ResolveTCPAddr("tcp4", weave.NormalisePeerAddr(peer)); err == nil {
+			router.ConnectionMaker.ForgetConnection(addr.String())
+		} else {
+			http.Error(w, fmt.Sprint("invalid peer address: ", err), http.StatusBadRequest)
+		}
+	})
+
 	http.Handle("/", muxRouter)
 
 	address := fmt.Sprintf(":%d", weave.HttpPort)