Add a REST API to query the active node's IP address

Change-Id: I48261a5988a291cc93795188bcf09e72e4fd9e4c
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/web/OpenstackManagementWebResource.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/web/OpenstackManagementWebResource.java
index c6776c7..7159222 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/web/OpenstackManagementWebResource.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/web/OpenstackManagementWebResource.java
@@ -105,6 +105,8 @@
     private static final String FLAG_TRUE = "true";
     private static final String FLAG_FALSE = "false";
 
+    private static final String ACTIVE_IP = "activeIp";
+
     private final ObjectNode root = mapper().createObjectNode();
     private final ArrayNode floatingipsNode = root.putArray(FLOATINGIPS);
 
@@ -439,6 +441,19 @@
     }
 
     /**
+     * Obtains the active node's IP address.
+     *
+     * @return 200 OK with active node's IP address.
+     */
+    @GET
+    @Path("active/ip")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response getActiveIp() {
+        return ok(mapper().createObjectNode()
+                .put(ACTIVE_IP, osHaService.getActiveIp().toString())).build();
+    }
+
+    /**
      * Configures the HA active IP address.
      *
      * @param ip IP address of active node