ONOS-3322 Sketch of Remote Service

Change-Id: I9c16b56b8d02d7f3995eafb1bb96211089774ca7

+/*
+ * Copyright 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.
+ */
+
+package org.onosproject.incubator.rpc;
+
+import com.google.common.annotations.Beta;
+
+// Implementation is expected to be a handler for RPC channel
+// and shim-layer to convert Java Service interface calls to/from RPC call
+/**
+ * Context for Remote service.
+ */
+@Beta
+public interface RemoteServiceContext {
+
+    // we may need a method to check connection state?
+
+    /**
+     * Returns implementation of the specified service class.
+     *
+     * @param serviceClass service class
+     * @param <T>          type of service
+     * @return implementation class
+     * @throws UnsupportedOperationException if this context does not support it.
+     */
+    <T> T get(Class<T> serviceClass);
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc;
+
+import java.net.URI;
+
+import org.onosproject.net.provider.Provider;
+
+import com.google.common.annotations.Beta;
+
+//Factory to create RemoteServiceContext
+/**
+ * Abstraction of a remote service implementation provider.
+ */
+@Beta
+public interface RemoteServiceContextProvider extends Provider {
+
+    /**
+     * Returns {@link RemoteServiceContext} for given URI.
+     *
+     * @param uri  URI for remote end point.
+     * @return {@link RemoteServiceContext}
+     */
+    RemoteServiceContext get(URI uri);
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc;
+
+import org.onosproject.net.provider.ProviderService;
+
+import com.google.common.annotations.Beta;
+
+// Not completely sure if we will make use of this at the moment
+// added to follow existing  {@link ProviderRegistry} pattern
+@Beta
+public interface RemoteServiceContextProviderService
+        extends ProviderService<RemoteServiceContextProvider> {
+
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc;
+
+import java.net.URI;
+
+import com.google.common.annotations.Beta;
+
+// This is actually the RPC Service, where consumers get
+// RemoteSericeContext (~= RPC Session) for given URI
+// expected to be implemented by some Manager class on Lower-side ONOS
+/**
+ * Service for retrieving RPC session handler ({@link RemoteServiceContext}).
+ */
+@Beta
+public interface RemoteServiceDirectory {
+
+    /**
+     * Returns remote service context.
+     *
+     * @param uri URI representing remote end point. e.g., (grpc://hostname:port)
+     * @return remote service context
+     * @throws UnsupportedOperationException if URI scheme was not supported.
+     */
+    RemoteServiceContext get(URI uri);
+
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc;
+
+import org.onosproject.net.provider.ProviderRegistry;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Abstraction of a remote service provider registry.
+ */
+@Beta
+public interface RemoteServiceProviderRegistry
+    extends ProviderRegistry<RemoteServiceContextProvider,
+                             RemoteServiceContextProviderService> {
+
+}

+/*
+ * Copyright 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.
+ */
+
+/**
+ * Incubating inter-cluster RPC APIs.
+ */
+package org.onosproject.incubator.rpc;

@@ -35,6 +35,7 @@
         <module>api</module>
         <module>api</module>
         <module>net</module>
         <module>net</module>
         <module>store</module>
         <module>store</module>
+        <module>rpc</module>
     </modules>
     </modules>
 
 
     <dependencies>
     <dependencies>

+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <artifactId>onos-incubator</artifactId>
+        <groupId>org.onosproject</groupId>
+        <version>1.4.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>onos-incubator-rpc</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS inter-cluster RPC service</description>
+    <url>http://onosproject.org</url>
+
+    <properties>
+        <onos.app.name>org.onosproject.incubator.rpc</onos.app.name>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onlab-osgi</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+            <scope>test</scope>
+            <classifier>tests</classifier>
+        </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-incubator-api</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+                <extensions>true</extensions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>generate-scr-srcdescriptor</id>
+                        <goals>
+                            <goal>scr</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <supportedProjectTypes>
+                        <supportedProjectType>bundle</supportedProjectType>
+                        <supportedProjectType>war</supportedProjectType>
+                    </supportedProjectTypes>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.onosproject</groupId>
+                <artifactId>onos-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>cfg</id>
+                        <phase>generate-resources</phase>
+                        <goals>
+                            <goal>cfg</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>swagger</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>swagger</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>app</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>app</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc.impl;
+
+import java.util.Map;
+import java.util.Set;
+
+import org.onosproject.incubator.rpc.RemoteServiceContextProvider;
+import org.onosproject.incubator.rpc.RemoteServiceContextProviderService;
+import org.onosproject.incubator.rpc.RemoteServiceProviderRegistry;
+import org.onosproject.net.provider.ProviderId;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Maps;
+
+// Probably should change name or add missing feature (provider from scheme) to
+//  org.onosproject.net.provider.AbstractProviderRegistry<P, S>
+@Beta
+abstract class AbstractProviderRegistry
+    implements RemoteServiceProviderRegistry {
+
+
+    private final Map<ProviderId, RemoteServiceContextProvider> pidToProvider = Maps.newConcurrentMap();
+    private final Map<String, RemoteServiceContextProvider> schemeToProvider = Maps.newConcurrentMap();
+
+    public AbstractProviderRegistry() {
+        super();
+    }
+
+    protected abstract RemoteServiceContextProviderService createProviderService(RemoteServiceContextProvider provider);
+
+    @Override
+    public synchronized RemoteServiceContextProviderService register(RemoteServiceContextProvider provider) {
+        // TODO check if it already exists
+        pidToProvider.put(provider.id(), provider);
+        schemeToProvider.put(provider.id().scheme(), provider);
+        return createProviderService(provider);
+    }
+
+    @Override
+    public synchronized void unregister(RemoteServiceContextProvider provider) {
+        pidToProvider.remove(provider.id(), provider);
+        schemeToProvider.remove(provider.id().scheme(), provider);
+    }
+
+    @Override
+    public Set<ProviderId> getProviders() {
+        return ImmutableSet.copyOf(pidToProvider.keySet());
+    }
+
+    protected RemoteServiceContextProvider getProvider(ProviderId pid) {
+        return pidToProvider.get(pid);
+    }
+
+    protected RemoteServiceContextProvider getProvider(String scheme) {
+        return schemeToProvider.get(scheme);
+    }
+
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import java.net.URI;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.osgi.DefaultServiceDirectory;
+import org.onlab.osgi.ServiceDirectory;
+import org.onosproject.incubator.rpc.RemoteServiceContext;
+import org.onosproject.incubator.rpc.RemoteServiceContextProvider;
+import org.onosproject.incubator.rpc.RemoteServiceContextProviderService;
+import org.onosproject.incubator.rpc.RemoteServiceProviderRegistry;
+import org.onosproject.net.provider.ProviderId;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Sample implementation of RemoteServiceContextProvider.
+ *
+ * Scheme: "local", calling corresponding local service on request.
+ * Only expected for testing until real RPC implementation is ready.
+ *
+ * Note: This is expected to be removed or separated out as separate bundle
+ * once other RPC implementaion became available.
+ */
+@Beta
+@Component(immediate = true)
+public class LocalRemoteServiceProvider implements RemoteServiceContextProvider {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private RemoteServiceContext theOne = new LocalServiceContext();
+
+    private static final ProviderId PID = new ProviderId("local", "org.onosproject.rpc.provider.local");
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected RemoteServiceProviderRegistry rpcRegistry;
+
+    private final Map<Class<? extends Object>, Object> services = new ConcurrentHashMap<>();
+
+    private RemoteServiceContextProviderService providerService;
+
+    @Activate
+    protected void activate() {
+
+        services.put(SomeOtherService.class, new SomeOtherServiceImpl());
+
+        providerService = rpcRegistry.register(this);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        rpcRegistry.unregister(this);
+        log.info("Stopped");
+    }
+
+    @Override
+    public ProviderId id() {
+        return PID;
+    }
+
+    @Override
+    public RemoteServiceContext get(URI uri) {
+        checkArgument(Objects.equals(uri.getScheme(), "local"));
+        return theOne;
+    }
+
+    private final class LocalServiceContext implements RemoteServiceContext {
+
+        private final ServiceDirectory directory = new DefaultServiceDirectory();
+
+        @Override
+        public <T> T get(Class<T> serviceClass) {
+            @SuppressWarnings("unchecked")
+            T service = (T) services.get(serviceClass);
+            if (service != null) {
+                return service;
+            }
+            // look up OSGi services on this host.
+            // provided to unblock development depending on RPC.
+            return directory.get(serviceClass);
+        }
+    }
+
+    // Service provided by RPC can be non-OSGi Service
+    public static interface SomeOtherService {
+        String hello();
+    }
+
+    public static class SomeOtherServiceImpl implements SomeOtherService {
+
+        @Override
+        public String hello() {
+            return "Goodbye";
+        }
+    }
+
+}

+/*
+ * Copyright 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.
+ */
+package org.onosproject.incubator.rpc.impl;
+
+import java.net.URI;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onosproject.incubator.rpc.RemoteServiceContext;
+import org.onosproject.incubator.rpc.RemoteServiceDirectory;
+import org.onosproject.incubator.rpc.RemoteServiceContextProvider;
+import org.onosproject.incubator.rpc.RemoteServiceContextProviderService;
+import org.onosproject.incubator.rpc.RemoteServiceProviderRegistry;
+import org.onosproject.net.provider.AbstractProviderService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Provides RemoteService related APIs.
+ */
+@Beta
+@Component(immediate = true)
+@Service
+public class RemoteServiceManager extends AbstractProviderRegistry
+    implements RemoteServiceDirectory, RemoteServiceProviderRegistry {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    @Activate
+    protected void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public RemoteServiceContext get(URI uri) {
+        RemoteServiceContextProvider factory = getProvider(uri.getScheme());
+        if (factory != null) {
+            return factory.get(uri);
+        }
+        throw new UnsupportedOperationException(uri.getScheme() + " not supported");
+    }
+
+    private final class InternalRemoteServiceContextProviderService
+            extends AbstractProviderService<RemoteServiceContextProvider>
+            implements RemoteServiceContextProviderService {
+
+        public InternalRemoteServiceContextProviderService(RemoteServiceContextProvider provider) {
+            super(provider);
+        }
+    }
+
+    // make this abstract method if slicing out
+    @Override
+    protected RemoteServiceContextProviderService createProviderService(RemoteServiceContextProvider provider) {
+        return new InternalRemoteServiceContextProviderService(provider);
+    }
+
+}

+/*
+ * Copyright 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.
+ */
+
+/**
+ * Implementation of the inter-cluster RPC service.
+ */
+package org.onosproject.incubator.rpc.impl;

+/*
+ * Copyright 2014 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.incubator.rpc.impl;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Set of tests of the ONOS application component.
+ */
+public class RemoteServiceManagerTest {
+
+    private RemoteServiceManager component;
+
+    @Before
+    public void setUp() {
+        component = new RemoteServiceManager();
+        component.activate();
+
+    }
+
+    @After
+    public void tearDown() {
+        component.deactivate();
+    }
+
+    @Test
+    public void basics() {
+
+    }
+
+}