[ONOS-4291] Implement skeleton of gateway load balancer

 - Implements scalable gateway service
 - Implements gateway node model

Change-Id: I3713c67edcff9b10ccb23a7ad3323f5c30c7d6a3
diff --git a/apps/scalablegateway/app/BUCK b/apps/scalablegateway/app/BUCK
new file mode 100644
index 0000000..81a0dad
--- /dev/null
+++ b/apps/scalablegateway/app/BUCK
@@ -0,0 +1,13 @@
+COMPILE_DEPS = [
+    '//lib:CORE_DEPS',
+    '//apps/scalablegateway/api:onos-app-scalablegateway-api',
+]
+
+TEST_DEPS = [
+    '//lib:TEST_ADAPTERS',
+]
+
+osgi_jar_with_tests (
+    deps = COMPILE_DEPS
+    test_deps = TEST_DEPS,
+)
diff --git a/apps/scalablegateway/app/pom.xml b/apps/scalablegateway/app/pom.xml
new file mode 100644
index 0000000..23105ac
--- /dev/null
+++ b/apps/scalablegateway/app/pom.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2016-present Open Networking Laboratory
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-scalablegateway</artifactId>
+        <version>1.6.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-scalablegateway-app</artifactId>
+    <packaging>bundle</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-app-scalablegateway-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+</project>
diff --git a/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/ScalableGatewayManager.java b/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/ScalableGatewayManager.java
new file mode 100644
index 0000000..eba3de8
--- /dev/null
+++ b/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/ScalableGatewayManager.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.scalablegateway;
+
+import org.onosproject.core.GroupId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+
+import java.util.List;
+
+/**
+ * Manages gateway node for gateway scalability.
+ */
+public class ScalableGatewayManager implements ScalableGatewayService {
+
+    @Override
+    public GatewayNode getGatewayNode(DeviceId deviceId) {
+        return null;
+    }
+
+    @Override
+    public List<PortNumber> getGatewayExternalPorts(DeviceId deviceId) {
+        return null;
+    }
+
+    @Override
+    public GroupId getGroupIdForGatewayLoadBalance(DeviceId srcDeviceId) {
+        return null;
+    }
+
+    @Override
+    public List<GatewayNode> getGatewayNodes() {
+        return null;
+    }
+
+    @Override
+    public List<DeviceId> getGatewayDeviceIds() {
+        return null;
+    }
+
+    @Override
+    public boolean addGatewayNode(GatewayNode gatewayNode) {
+        return false;
+    }
+
+    @Override
+    public boolean deleteGatewayNode(GatewayNode gatewayNode) {
+        return false;
+    }
+}
diff --git a/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/package-info.java b/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/package-info.java
new file mode 100644
index 0000000..1768150
--- /dev/null
+++ b/apps/scalablegateway/app/src/main/java/org/onosproject/scalablegateway/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Application for ScaleableGateway management.
+ */
+package org.onosproject.scalablegateway;
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