Reserve POD IP address to avoid allocating duplicated IP addresses

Change-Id: I0fa42d0d17a35184730e797e394502dfceae7525
diff --git a/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sIpamAdminService.java b/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sIpamAdminService.java
index d8752f8..fbca1b3 100644
--- a/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sIpamAdminService.java
+++ b/apps/k8s-networking/api/src/main/java/org/onosproject/k8snetworking/api/K8sIpamAdminService.java
@@ -33,6 +33,14 @@
     IpAddress allocateIp(String networkId);
 
     /**
+     * Reserves an IP address with the given network.
+     *
+     * @param networkId network identifier
+     * @param ipAddress IP address
+     */
+    void reserveIp(String networkId, IpAddress ipAddress);
+
+    /**
      * Releases the IP address from the given network.
      *
      * @param networkId network identifier