framework to publish and subscribe events

framework/events/pom.xml

@@ -0,0 +1,30 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements. See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership. The ASF licenses this file
+  to you 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>
+  <artifactId>cloud-framework-events</artifactId>
+  <name>Apache CloudStack Event Notification Framework</name>
+  <parent>
+    <groupId>org.apache.cloudstack</groupId>
+    <artifactId>cloudstack</artifactId>
+    <version>4.0.0-SNAPSHOT</version>
+    <relativePath>../../pom.xml</relativePath>
+  </parent>
+</project>

framework/events/src/org/apache/cloudstack/framework/events/EventBus.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+import com.cloud.utils.component.Adapter;
+import java.util.Map;
+
+/**
+ * Publish and Subscribe provider interface
+ *
+ */
+public interface EventBus extends Adapter{
+    /**
+     * Publish an event
+     * 
+     * @param category category of the event being published (e.g. action, usage, alert etc)
+     * @param type type of the event (e.g. vm stop, volume delete etc)
+     * @param description description of the event
+     * @return true if the event has been successfully published.
+     */
+    boolean publish(String category, String type, Map<String, String> description);
+
+    /**
+     * Subscribe to events of a category and a type
+     *  
+     * @param category category of the event being subscribed (e.g. action, usage, alert etc)
+     * @param type type of the event (e.g. vm stop, volume delete etc)
+     * @param subscriber class that is intends to receive subscribed event
+     * @return true if the subscribe has been successfully registered.
+     */
+    boolean subscribe(String category, String type, EventSubscriber subscriber);
+}

framework/events/src/org/apache/cloudstack/framework/events/EventCategory.java

@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+public class EventCategory {
+    public static final String ACTION_EVENT = "Action Event";
+    public static final String USAGE_EVENT = "Usage Event";
+    public static final String ALERT_EVENT = "Alert Event";
+}

framework/events/src/org/apache/cloudstack/framework/events/EventPublisher.java

@@ -0,0 +1,107 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.cloud.utils.component.Adapters;
+import com.cloud.utils.component.ComponentLocator;
+import com.cloud.utils.component.AnnotationInterceptor;
+
+import net.sf.cglib.proxy.Callback;
+import net.sf.cglib.proxy.MethodInterceptor;
+import net.sf.cglib.proxy.MethodProxy;
+
+public class EventPublisher implements MethodInterceptor, AnnotationInterceptor<Publish> {
+
+    private static EventBus _eventBus = null;
+
+    @Override
+    public Object intercept(Object object, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
+        Publish event = interceptStart(method);
+        boolean success = true;
+        try {
+            return methodProxy.invokeSuper(object, args);
+        } catch (Exception e){
+            success = false;
+            interceptException(method, event);
+            throw e;
+        } finally {
+            if(success){
+                interceptComplete(method, event);
+            }
+        }
+    }
+
+    @Override
+    public boolean needToIntercept(AnnotatedElement element) {
+        if (!(element instanceof Method)) {
+            return false;
+            
+        }
+        Method method = (Method)element;
+        Publish event = method.getAnnotation(Publish.class);
+        if (event != null) {
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public Publish interceptStart(AnnotatedElement element) {
+        return null;
+    }
+
+    @Override
+    public void interceptComplete(AnnotatedElement element, Publish event) {
+        _eventBus = getEventBus();
+        if (_eventBus != null) {
+            Map<String, String> description = new HashMap<String, String>();
+            description.put("description", event.eventDescription());
+            _eventBus.publish(event.eventCategory(), event.eventType(), description);
+        }
+    }
+
+    @Override
+    public void interceptException(AnnotatedElement element, Publish attach) {
+        return;
+    }
+
+    @Override
+    public Callback getCallback() {
+        return this;
+    }
+    
+    private EventBus getEventBus() {
+        if (_eventBus == null) {
+            ComponentLocator locator = ComponentLocator.getLocator("management-server");
+            Adapters<EventBus> eventBusImpls = locator.getAdapters(EventBus.class);
+            if (eventBusImpls != null) {
+                Enumeration<EventBus> eventBusenum = eventBusImpls.enumeration();
+                _eventBus = eventBusenum.nextElement();
+            }
+        }
+        return _eventBus;
+    }
+}

framework/events/src/org/apache/cloudstack/framework/events/EventSubscriber.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+import java.util.Map;
+
+public interface EventSubscriber {
+
+    /**
+     * Callback method. EventBus calls this method on occurrence of subscribed event
+     *  
+     * @param category category of the event being subscribed (e.g. action, usage, alert etc) 
+     * @param type type of the event (e.g. vm stop, volume delete etc)
+     * @param description description of the event
+     */
+    void recieve(String category, String type, Map<String, String> description);
+}

framework/events/src/org/apache/cloudstack/framework/events/Publish.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+@Target({ TYPE, METHOD })
+@Retention(RUNTIME)
+public @interface Publish {
+
+    String eventCategory();
+
+    String eventType();
+
+    String eventDescription();
+}

framework/events/src/org/apache/cloudstack/framework/events/Subscribe.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.cloudstack.framework.events;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+@Target({METHOD })
+@Retention(RUNTIME)
+public @interface Subscribe {
+	
+    String eventCategory();
+
+    String eventType();
+}

pom.xml

@@ -157,6 +157,7 @@
     <module>awsapi</module>
     <module>patches</module>
     <module>test</module>
+    <module>framework/events</module>
   </modules>
 
   <dependencies>

server/src/com/cloud/configuration/DefaultInterceptorLibrary.java

@@ -22,6 +22,7 @@ import com.cloud.event.ActionEventCallback;
 import com.cloud.utils.component.AnnotationInterceptor;
 import com.cloud.utils.component.InterceptorLibrary;
 import com.cloud.utils.db.DatabaseCallback;
+import org.apache.cloudstack.framework.events.EventPublisher;
 
 public class DefaultInterceptorLibrary implements InterceptorLibrary {
 
@@ -29,5 +30,6 @@ public class DefaultInterceptorLibrary implements InterceptorLibrary {
     public void addInterceptors(List<AnnotationInterceptor<?>> interceptors) {
         interceptors.add(new DatabaseCallback());
         interceptors.add(new ActionEventCallback());
+        interceptors.add(new EventPublisher());
     }
 }