Port Alerters architecture (#359)

actions/actions-impl/src/main/java/org/hawkular/alerts/actions/standalone/ActionPlugins.java

@@ -99,7 +99,7 @@ private void scan() throws IOException {
                                 }
                             }
                         } catch (Exception e) {
-                            log.errorf("Error loading Handler %s. Reason: %s", className, e.toString());
+                            log.errorf("Error loading ActionPlugin %s. Reason: %s", className, e.toString());
                             System.exit(1);
                         }
                     }

actions/actions-impl/src/main/java/org/hawkular/alerts/actions/standalone/StandaloneActionPluginRegister.java

@@ -64,7 +64,7 @@ public void init() {
                     definitions.addActionPlugin(actionPlugin, properties);
                 }
             } catch (Exception e) {
-                log.errorCannotRegisterPlugin(actionPlugin, e.getMessage());
+                log.errorCannotRegisterPlugin(actionPlugin, e.toString());
             }
         }
         ActionListener actionListener = new StandaloneActionPluginListener(ActionPlugins.getPlugins(), executor);
@@ -95,5 +95,6 @@ public static synchronized void stop() {
                 }
             });
         }
+        instance = null;
     }
 }

alerters/alerters-api/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright 2015-2017 Red Hat, Inc. and/or its affiliates
+    and other contributors as indicated by the @author tags.
+
+    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>
+    <groupId>org.hawkular.alerts</groupId>
+    <artifactId>hawkular-alerts-alerters</artifactId>
+    <version>2.0.0.Final-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>hawkular-alerts-alerters-api</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Hawkular Alerting: Alerters Api</name>
+
+</project>

alerters/alerters-api/src/main/java/org/hawkular/alerts/alerters/api/Alerter.java

@@ -0,0 +1,20 @@
+package org.hawkular.alerts.alerters.api;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Define an alerters plugin implementation
+ * Plugin must have a unique name that will be used at registration phase
+ * Plugin must implement AlerterPlugin interface
+ *
+ * @author Jay Shaughnessy
+ * @author Lucas Ponce
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface Alerter {
+    String name();
+}

alerters/alerters-api/src/main/java/org/hawkular/alerts/alerters/api/AlerterPlugin.java

@@ -0,0 +1,16 @@
+package org.hawkular.alerts.alerters.api;
+
+import java.util.concurrent.ExecutorService;
+
+import org.hawkular.alerts.api.services.AlertsService;
+import org.hawkular.alerts.api.services.DefinitionsService;
+
+/**
+ * @author Jay Shaughnessy
+ * @author Lucas Ponce
+ */
+public interface AlerterPlugin {
+
+    void init(DefinitionsService definitions, AlertsService alerts, ExecutorService executor);
+    void stop();
+}

alerters/alerters-impl/pom.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright 2015-2017 Red Hat, Inc. and/or its affiliates
+    and other contributors as indicated by the @author tags.
+
+    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>
+    <groupId>org.hawkular.alerts</groupId>
+    <artifactId>hawkular-alerts-alerters</artifactId>
+    <version>2.0.0.Final-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>hawkular-alerts-alerters-impl</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Hawkular Alerting: Alerters Implementation</name>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>org.hawkular.alerts</groupId>
+      <artifactId>hawkular-alerts-alerters-api</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.hawkular.alerts</groupId>
+      <artifactId>hawkular-alerts-engine</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+
+  </dependencies>
+
+</project>

alerters/alerters-impl/src/main/java/org/hawkular/alerts/alerters/standalone/AlerterPlugins.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015-2016 Red Hat, Inc. and/or its affiliates
+ * and other contributors as indicated by the @author tags.
+ *
+ * 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.hawkular.alerts.alerters.standalone;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+import org.hawkular.alerts.alerters.api.Alerter;
+import org.hawkular.alerts.alerters.api.AlerterPlugin;
+import org.hawkular.alerts.api.services.AlertsService;
+import org.hawkular.alerts.api.services.DefinitionsService;
+import org.hawkular.alerts.engine.StandaloneAlerts;
+import org.hawkular.commons.log.MsgLogger;
+import org.hawkular.commons.log.MsgLogging;
+
+/**
+ * Helper class to find the classes annotated with ActionPlugin and instantiate them.
+ *
+ * @author Lucas Ponce
+ */
+public class AlerterPlugins {
+    private static final MsgLogger log = MsgLogging.getMsgLogger(AlerterPlugins.class);
+    private static AlerterPlugins instance;
+    private Map<String, AlerterPlugin> plugins;
+    private ClassLoader cl = Thread.currentThread().getContextClassLoader();
+
+    DefinitionsService definitions;
+    AlertsService alerts;
+    ExecutorService executor;
+
+    public static synchronized Map<String, AlerterPlugin> getPlugins() {
+        if (instance == null) {
+            instance = new AlerterPlugins();
+        }
+        return Collections.unmodifiableMap(instance.plugins);
+    }
+
+    private AlerterPlugins() {
+        try {
+            plugins = new HashMap<>();
+            definitions = StandaloneAlerts.getDefinitionsService();
+            alerts = StandaloneAlerts.getAlertsService();
+            executor = StandaloneAlerts.getExecutor();
+            scan();
+        } catch (Exception e) {
+            throw new IllegalStateException(e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private void scan() throws IOException {
+        String[] classpath = System.getProperty("java.class.path").split(":");
+        for (int i=0; i<classpath.length; i++) {
+            if (classpath[i].contains("hawkular") && classpath[i].endsWith("jar")) {
+                ZipInputStream zip = new ZipInputStream(new FileInputStream(classpath[i]));
+                for (ZipEntry entry = zip.getNextEntry(); entry != null; entry = zip.getNextEntry()) {
+                    if (!entry.isDirectory() && entry.getName().endsWith(".class")) {
+                        String className = entry.getName().replace('/', '.'); // including ".class"
+                        className = className.substring(0, className.length() - 6);
+                        try {
+                            Class clazz = cl.loadClass(className);
+                            if (clazz.isAnnotationPresent(Alerter.class)) {
+                                Alerter alerter = (Alerter)clazz.getAnnotation(Alerter.class);
+                                String name = alerter.name();
+                                Object newInstance = clazz.newInstance();
+                                log.infof("Scanning %s", clazz.getName());
+                                if (newInstance instanceof AlerterPlugin) {
+                                    AlerterPlugin pluginInstance = (AlerterPlugin)newInstance;
+                                    pluginInstance.init(definitions, alerts, executor);
+                                    plugins.put(name, pluginInstance);
+                                } else {
+                                    throw new IllegalStateException("Alerter [" + name + "] is not instance of " +
+                                            "AlerterPlugin");
+                                }
+                            }
+                        } catch (Exception e) {
+                            log.errorf("Error loading AlerterPlugin %s. Reason: %s", className, e.toString());
+                            System.exit(1);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

alerters/alerters-impl/src/main/java/org/hawkular/alerts/alerters/standalone/StandaloneAlerterPluginRegister.java

@@ -0,0 +1,51 @@
+package org.hawkular.alerts.alerters.standalone;
+
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+
+import org.hawkular.alerts.alerters.api.AlerterPlugin;
+import org.hawkular.commons.log.MsgLogger;
+import org.hawkular.commons.log.MsgLogging;
+
+/**
+ * @author Jay Shaughnessy
+ * @author Lucas Ponce
+ */
+public class StandaloneAlerterPluginRegister {
+    private static final MsgLogger log = MsgLogging.getMsgLogger(StandaloneAlerterPluginRegister.class);
+
+    private static StandaloneAlerterPluginRegister instance;
+    private static ExecutorService executor;
+
+    Map<String, AlerterPlugin> plugins;
+
+    private StandaloneAlerterPluginRegister() {
+        init();
+    }
+
+    public static void setExecutor(ExecutorService executor) {
+        StandaloneAlerterPluginRegister.executor = executor;
+    }
+
+    public void init() {
+        plugins = AlerterPlugins.getPlugins();
+        log.info("Alerter Plugins load finished");
+    }
+
+    public static synchronized void start() {
+        if (instance == null) {
+            instance = new StandaloneAlerterPluginRegister();
+        }
+    }
+
+    public static synchronized void stop() {
+        if (instance != null && instance.plugins != null) {
+            instance.plugins.entrySet().stream().forEach(pluginEntry -> {
+                log.infof("Stopping Alerter %s", pluginEntry.getKey());
+                pluginEntry.getValue().stop();
+            });
+        }
+        instance = null;
+    }
+
+}

alerters/alerters-plugins/alerters-elasticsearch/pom.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright 2015-2017 Red Hat, Inc. and/or its affiliates
+    and other contributors as indicated by the @author tags.
+
+    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>
+    <groupId>org.hawkular.alerts</groupId>
+    <artifactId>hawkular-alerts-alerters-plugins</artifactId>
+    <version>2.0.0.Final-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>hawkular-alerts-alerters-elasticsearch</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Hawkular Alerting: Alerter Elasticsearch Plugin</name>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>org.elasticsearch.client</groupId>
+      <artifactId>rest</artifactId>
+      <version>${version.org.elasticsearch.client}</version>
+    </dependency>
+
+    <!-- Tests -->
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+      <version>${version.junit}</version>
+    </dependency>
+
+  </dependencies>
+
+</project>