command/agent: find proper private IP on Windows

/cc @armon

CHANGELOG.md

@@ -1,12 +1,5 @@
 ## 0.2.1 (unreleased)
 
-FEATURES:
-
-BUG FIXES:
-
- * Renaming "seperator" to "separator". This is the correct spelling,
- but both spellings are respected for backwards compatibility. [GH-101]
-
 IMPROVEMENTS:
 
   * Improved the URL formatting for the key/value editor in the Web UI.
@@ -16,6 +9,12 @@ IMPROVEMENTS:
       editor. [GH-124], [GH-122]
   * Add flag to agent to write pid to a file. [GH-106]
 
+BUG FIXES:
+
+  * Renaming "seperator" to "separator". This is the correct spelling,
+      but both spellings are respected for backwards compatibility. [GH-101]
+  * Private IP is properly found on Windows clients.
+
 ## 0.2.0 (May 1, 2014)
 
 FEATURES:

command/agent/agent.go

@@ -79,7 +79,7 @@ func Create(config *Config, logOutput io.Writer) (*Agent, error) {
 		if err != nil {
 			return nil, fmt.Errorf("Failed to get advertise address: %v", err)
 		}
-		config.AdvertiseAddr = ip.IP.String()
+		config.AdvertiseAddr = ip.String()
 	}
 
 	agent := &Agent{

consul/util.go

@@ -106,26 +106,34 @@ func isPrivateIP(ip_str string) bool {
 
 // GetPrivateIP is used to return the first private IP address
 // associated with an interface on the machine
-func GetPrivateIP() (*net.IPNet, error) {
+func GetPrivateIP() (net.IP, error) {
 	addresses, err := net.InterfaceAddrs()
 	if err != nil {
 		return nil, fmt.Errorf("Failed to get interface addresses: %v", err)
 	}
 
 	// Find private IPv4 address
-	for _, addr := range addresses {
-		ip, ok := addr.(*net.IPNet)
-		if !ok {
+	for _, rawAddr := range addresses {
+		var ip net.IP
+		switch addr := rawAddr.(type) {
+		case *net.IPAddr:
+			ip = addr.IP
+		case *net.IPNet:
+			ip = addr.IP
+		default:
 			continue
 		}
-		if ip.IP.To4() == nil {
+
+		if ip.To4() == nil {
 			continue
 		}
-		if !isPrivateIP(ip.IP.String()) {
+		if !isPrivateIP(ip.String()) {
 			continue
 		}
+
 		return ip, nil
 	}
+
 	return nil, fmt.Errorf("No private IP address found")
 }