Weave script calls Go implementation of expose_nat

prog/weaveutil/expose.go

@@ -0,0 +1,23 @@
+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

@@ -34,6 +34,7 @@ func init() {
 		"list-netdevs":           listNetDevs,
 		"cni-net":                cniNet,
 		"cni-ipam":               cniIPAM,
+		"expose-nat":             exposeNAT,
 	}
 }
 

weave

@@ -661,14 +661,6 @@ expose_ip() {
     done
 }
 
-expose_nat() {
-    for CIDR in $ALL_CIDRS ; do
-        add_iptables_rule nat WEAVE -s $CIDR -d 224.0.0.0/4 -j RETURN
-        add_iptables_rule nat WEAVE -d $CIDR ! -s $CIDR -j MASQUERADE
-        add_iptables_rule nat WEAVE -s $CIDR ! -d $CIDR -j MASQUERADE
-    done
-}
-
 # create veth with ends $1-$2, and then invoke $3..., removing the
 # veth on failure. No-op of veth already exists.
 create_veth() {
@@ -2222,7 +2214,7 @@ EOF
         fi
         create_bridge --without-ethtool
         expose_ip
-        expose_nat
+        util_op expose-nat $ALL_CIDRS
         show_addrs $ALL_CIDRS
         ;;
     hide)