Handle "weave expose" in weaver

The change makes "weave expose" to call the "/expose" HTTP
endpoint implemented in router which exposes the bridge.

Such architectural change required as we need to know whether NPC is
enabled when exposing the bridge and weaver knows this fact the best.

Unfortunately, this change makes impossible to "weave expose"
when weaver is not running.

prog/weaver/main.go

@@ -322,7 +322,7 @@ func main() {
 	checkFatal(err)
 	defer db.Close()
 
-	router, err := weave.NewNetworkRouter(config, networkConfig, name, nickName, overlay, db)
+	router, err := weave.NewNetworkRouter(config, networkConfig, bridgeConfig, name, nickName, overlay, db)
 	checkFatal(err)
 	Log.Println("Our name is", router.Ourself)
 
@@ -469,17 +469,17 @@ func main() {
 		// Run this on its own goroutine because the allocator can block
 		// We remove the default route installed by the kernel,
 		// because awsvpc has installed it as well
-		go expose(allocator, defaultSubnet, bridgeConfig.WeaveBridgeName, bridgeConfig.AWSVPC, waitReady.Add())
+		go exposeForAWSVPC(allocator, defaultSubnet, bridgeConfig.WeaveBridgeName, waitReady.Add())
 	}
 
 	signals.SignalHandlerLoop(common.Log, router)
 }
 
-func expose(alloc *ipam.Allocator, subnet address.CIDR, bridgeName string, removeDefaultRoute bool, ready func()) {
+func exposeForAWSVPC(alloc *ipam.Allocator, subnet address.CIDR, bridgeName string, ready func()) {
 	addr, err := alloc.Allocate("weave:expose", subnet, false, func() bool { return false })
 	checkFatal(err)
 	cidr := address.MakeCIDR(subnet, addr)
-	err = weavenet.AddBridgeAddr(bridgeName, cidr.IPNet(), removeDefaultRoute)
+	err = weavenet.Expose(bridgeName, cidr.IPNet(), true, false)
 	checkFatal(err)
 	Log.Printf("Bridge %q exposed on address %v", bridgeName, cidr)
 	ready()

prog/weaveutil/expose.go

@@ -1,23 +0,0 @@
-package main
-
-import (
-	weavenet "github.com/weaveworks/weave/net"
-)
-
-func exposeNAT(args []string) error {
-	if len(args) < 1 {
-		cmdUsage("expose-nat", "<cidr>...")
-	}
-
-	cidrs, err := parseCIDRs(args)
-	if err != nil {
-		return err
-	}
-
-	for _, cidr := range cidrs {
-		if err := weavenet.ExposeNAT(*cidr); err != nil {
-			return err
-		}
-	}
-	return nil
-}

prog/weaveutil/main.go

@@ -45,7 +45,6 @@ func init() {
 		"list-netdevs":             listNetDevs,
 		"cni-net":                  cniNet,
 		"cni-ipam":                 cniIPAM,
-		"expose-nat":               exposeNAT,
 		"bridge-ip":                bridgeIP,
 		"unique-id":                uniqueID,
 		"swarm-manager-peers":      swarmManagerPeers,