[ONOS-3370] Extract hostprovider and lldpprovider from openflow

There are three independent apps:
    - openflow-base
    - hostprovider
    - lldpprovider
And there is also one meta-application called openflow that
contains all three of them.

Also fix the dependency issue when the apps are loaded from disk

Change-Id: I6da584e03593db9094b3a57976b28291f207c3c6
diff --git a/core/store/dist/src/main/java/org/onosproject/store/app/GossipApplicationStore.java b/core/store/dist/src/main/java/org/onosproject/store/app/GossipApplicationStore.java
index dda820a..fe4aa0b 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/app/GossipApplicationStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/app/GossipApplicationStore.java
@@ -183,21 +183,34 @@
      * they are marked to be active.
      */
     private void loadFromDisk() {
-        for (String name : getApplicationNames()) {
-            for (int i = 0; i < MAX_LOAD_RETRIES; i++) {
-                try {
-                    Application app = create(getApplicationDescription(name), false);
-                    if (app != null && isActive(app.id().name())) {
-                        requiredBy.put(app.id(), coreAppId);
-                        activate(app.id(), false);
-                        // load app permissions
-                    }
-                } catch (Exception e) {
-                    log.warn("Unable to load application {} from disk; retrying", name);
-                    randomDelay(RETRY_DELAY_MS);  // FIXME: This is a deliberate hack; fix in Drake
+        getApplicationNames().forEach(appName -> {
+            Application app = loadFromDisk(appName);
+            if (app != null && isActive(app.id().name())) {
+                activate(app.id(), false);
+                // TODO Load app permissions
+            }
+        });
+    }
+
+    private Application loadFromDisk(String appName) {
+        for (int i = 0; i < MAX_LOAD_RETRIES; i++) {
+            try {
+                // Directly return if app already exists
+                ApplicationId appId = getId(appName);
+                if (appId != null) {
+                    return getApplication(appId);
                 }
+
+                ApplicationDescription appDesc = getApplicationDescription(appName);
+                boolean success = appDesc.requiredApps().stream()
+                        .noneMatch(requiredApp -> loadFromDisk(requiredApp) == null);
+                return success ? create(appDesc, false) : null;
+            } catch (Exception e) {
+                log.warn("Unable to load application {} from disk; retrying", appName);
+                randomDelay(RETRY_DELAY_MS); //FIXME: This is a deliberate hack; fix in Falcon
             }
         }
+        return null;
     }
 
     @Deactivate
diff --git a/providers/host/pom.xml b/providers/host/pom.xml
index e8f32ca..ddbdbfc 100644
--- a/providers/host/pom.xml
+++ b/providers/host/pom.xml
@@ -29,7 +29,11 @@
     <artifactId>onos-host-provider</artifactId>
     <packaging>bundle</packaging>
 
-    <description>ONOS host tracking provider</description>
+    <properties>
+        <onos.app.name>org.onosproject.hostprovider</onos.app.name>
+    </properties>
+
+    <description>ONOS host location provider</description>
     <dependencies>
         <dependency>
             <groupId>org.onosproject</groupId>
diff --git a/providers/lldp/pom.xml b/providers/lldp/pom.xml
index e47d26c..7bf92ed 100644
--- a/providers/lldp/pom.xml
+++ b/providers/lldp/pom.xml
@@ -30,7 +30,11 @@
     <artifactId>onos-lldp-provider</artifactId>
     <packaging>bundle</packaging>
 
-    <description>ONOS LLDP Link Discovery</description>
+    <properties>
+        <onos.app.name>org.onosproject.lldpprovider</onos.app.name>
+    </properties>
+
+    <description>ONOS LLDP link provider</description>
 
     <dependencies>
         <dependency>
diff --git a/providers/openflow/app/pom.xml b/providers/openflow/app/pom.xml
index cb55463..ac5f6ee 100644
--- a/providers/openflow/app/pom.xml
+++ b/providers/openflow/app/pom.xml
@@ -27,55 +27,23 @@
     </parent>
 
     <artifactId>onos-openflow</artifactId>
-    <packaging>pom</packaging>
+    <packaging>bundle</packaging>
 
-    <description>OpenFlow protocol southbound providers</description>
+    <properties>
+        <onos.app.name>org.onosproject.openflow</onos.app.name>
+        <onos.app.requires>
+            org.onosproject.openflow-base,
+            org.onosproject.hostprovider,
+            org.onosproject.lldpprovider
+        </onos.app.requires>
+    </properties>
+
+    <description>OpenFlow southbound meta application</description>
 
     <dependencies>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-api</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-ctl</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-drivers</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-provider-device</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-provider-packet</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-provider-flow</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-of-provider-group</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-lldp-provider</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-host-provider</artifactId>
-            <version>${project.version}</version>
-        </dependency>
+    <dependency>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-of-api</artifactId>
+    </dependency>
     </dependencies>
-
 </project>
diff --git a/providers/openflow/app/app.xml b/providers/openflow/base/app.xml
similarity index 83%
rename from providers/openflow/app/app.xml
rename to providers/openflow/base/app.xml
index e54d1a8..34e6b15 100644
--- a/providers/openflow/app/app.xml
+++ b/providers/openflow/base/app.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
-  ~ Copyright 2015 Open Networking Laboratory
+  ~ Copyright 2014-2015 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.
@@ -14,7 +14,7 @@
   ~ See the License for the specific language governing permissions and
   ~ limitations under the License.
   -->
-<app name="org.onosproject.openflow" origin="ON.Lab" version="${project.version}"
+<app name="org.onosproject.openflow-base" origin="ON.Lab" version="${project.version}"
      featuresRepo="mvn:${project.groupId}/${project.artifactId}/${project.version}/xml/features"
      features="${project.artifactId}">
     <description>${project.description}</description>
@@ -23,8 +23,6 @@
     <artifact>mvn:${project.groupId}/onos-of-ctl/${project.version}</artifact>
     <artifact>mvn:${project.groupId}/onos-drivers/${project.version}</artifact>
 
-    <artifact>mvn:${project.groupId}/onos-lldp-provider/${project.version}</artifact>
-    <artifact>mvn:${project.groupId}/onos-host-provider/${project.version}</artifact>
     <artifact>mvn:${project.groupId}/onos-of-provider-device/${project.version}</artifact>
     <artifact>mvn:${project.groupId}/onos-of-provider-packet/${project.version}</artifact>
     <artifact>mvn:${project.groupId}/onos-of-provider-flow/${project.version}</artifact>
diff --git a/providers/openflow/app/features.xml b/providers/openflow/base/features.xml
similarity index 88%
rename from providers/openflow/app/features.xml
rename to providers/openflow/base/features.xml
index 9dbae8a..ed6b938 100644
--- a/providers/openflow/app/features.xml
+++ b/providers/openflow/base/features.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <!--
-  ~ Copyright 2015 Open Networking Laboratory
+  ~ Copyright 2014-2015 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.
@@ -23,8 +23,6 @@
         <bundle>mvn:${project.groupId}/onos-of-api/${project.version}</bundle>
         <bundle>mvn:${project.groupId}/onos-of-ctl/${project.version}</bundle>
 
-        <bundle>mvn:${project.groupId}/onos-lldp-provider/${project.version}</bundle>
-        <bundle>mvn:${project.groupId}/onos-host-provider/${project.version}</bundle>
         <bundle>mvn:${project.groupId}/onos-of-provider-device/${project.version}</bundle>
         <bundle>mvn:${project.groupId}/onos-of-provider-packet/${project.version}</bundle>
         <bundle>mvn:${project.groupId}/onos-of-provider-flow/${project.version}</bundle>
diff --git a/providers/openflow/base/pom.xml b/providers/openflow/base/pom.xml
new file mode 100644
index 0000000..9eb170c
--- /dev/null
+++ b/providers/openflow/base/pom.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2014-2015 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-of-providers</artifactId>
+        <version>1.4.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-openflow-base</artifactId>
+    <packaging>pom</packaging>
+
+    <description>OpenFlow protocol southbound providers</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-ctl</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-drivers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-provider-device</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-provider-packet</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-provider-flow</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-of-provider-group</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+</project>
diff --git a/providers/openflow/pom.xml b/providers/openflow/pom.xml
index c098a60..1250af6 100644
--- a/providers/openflow/pom.xml
+++ b/providers/openflow/pom.xml
@@ -37,6 +37,7 @@
         <module>flow</module>
         <module>group</module>
         <module>meter</module>
+        <module>base</module>
         <module>app</module>
     </modules>