Don't allow duplicate values in NodeAddresses

pkg/api/types.go

@@ -1405,3 +1405,19 @@ const (
 
 	PortHeader = "port"
 )
+
+// Appends the NodeAddresses to the passed-by-pointer slice, only if they do not already exist
+func AddToNodeAddresses(addresses *[]NodeAddress, addAddresses ...NodeAddress) {
+	for _, add := range addAddresses {
+		exists := false
+		for _, existing := range *addresses {
+			if existing.Address == add.Address && existing.Type == add.Type {
+				exists = true
+				break
+			}
+		}
+		if !exists {
+			*addresses = append(*addresses, add)
+		}
+	}
+}