create actor builder, add cluster join actor

config/config.hocon

@@ -12,6 +12,7 @@ jvmMetricsCollectionInterval="PT.5S"
 maxConnectionTimeout="PT2M"
 minConnectionTimeout="PT1M"
 clusterHostSuffix=".cluster"
+clusterJoinActor.type="com.arpnetworking.akka.NonJoiningClusterJoiner"
 rebalanceConfiguration {
   maxParallel=100
   threshold=500

src/main/java/com/arpnetworking/akka/ActorBuilder.java

@@ -0,0 +1,46 @@
+/**
+ * Copyright 2016 InscopeMetrics, Inc
+ *
+ * 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 com.arpnetworking.akka;
+
+import akka.actor.Props;
+import com.arpnetworking.commons.builder.OvalBuilder;
+
+import java.util.function.Function;
+
+/**
+ * Builder for actors.
+ *
+ * @param <B> The type of the builder
+ * @author Brandon Arp (brandon dot arp at inscopemetrics dot com)
+ */
+public abstract class ActorBuilder<B extends ActorBuilder<B>> extends OvalBuilder<Props> {
+    /**
+     * Protected constructor.
+     *
+     * @param createProps method to create a {@link Props} from the {@link ActorBuilder}
+     */
+    protected ActorBuilder(final Function<B, Props> createProps) {
+        super(createProps);
+    }
+
+    /**
+     * Called by setters to always return appropriate subclass of
+     * {@link ActorBuilder}, even from setters of base class.
+     *
+     * @return instance with correct {@link ActorBuilder} class type.
+     */
+    protected abstract B self();
+}

src/main/java/com/arpnetworking/akka/NonJoiningClusterJoiner.java

@@ -0,0 +1,90 @@
+/**
+ * Copyright 2016 Inscope Metrics, Inc
+ *
+ * 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 com.arpnetworking.akka;
+
+import akka.actor.Props;
+import akka.actor.UntypedActor;
+import com.arpnetworking.steno.Logger;
+import com.arpnetworking.steno.LoggerFactory;
+
+/**
+ * Actor that does not attempt to join a cluster.
+ *
+ * @author Brandon Arp (brandon dot arp at inscopemetrics dot com)
+ */
+public final class NonJoiningClusterJoiner extends UntypedActor {
+    /**
+     * Static factory method for creating a {@link Props} to create a {@link NonJoiningClusterJoiner} actor.
+     *
+     * @return a new {@link Props}
+     */
+    public static Props props() {
+        return Props.create(NonJoiningClusterJoiner.class);
+    }
+
+    /**
+     * Static factory method for creating a {@link Props} to create a {@link NonJoiningClusterJoiner} actor from a
+     * {@link Builder}.
+     *
+     * @param builder Builder to create the Props from
+     * @return a new {@link Props}
+     */
+    private static Props props(final Builder builder) {
+        return props();
+    }
+
+    /**
+     * Public constructor.
+     */
+    public NonJoiningClusterJoiner() {
+        LOGGER.info()
+                .setMessage("NonJoiningClusterJoiner starting up")
+                .log();
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void onReceive(final Object message) throws Exception {
+        unhandled(message);
+    }
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(NonJoiningClusterJoiner.class);
+
+    /**
+     * Implementation of the {@link com.arpnetworking.commons.builder.Builder} pattern for a {@link NonJoiningClusterJoiner}.
+     *
+     * @author Brandon Arp (brandon dot arp at inscopemetrics dot com)
+     */
+    public static class Builder extends ActorBuilder<Builder> {
+        /**
+         * Public constructor.
+         */
+        public Builder() {
+            super(NonJoiningClusterJoiner::props);
+        }
+
+        /**
+         * {@inheritDoc}
+         */
+        @Override
+        public Builder self() {
+            return this;
+        }
+    }
+}

src/main/java/com/arpnetworking/clusteraggregator/GuiceModule.java

@@ -164,54 +164,39 @@ private ActorSystem provideActorSystem(@Named("akka-config") final Config akkaCo
     @Named("cluster-emitter")
     @SuppressFBWarnings("UPM_UNCALLED_PRIVATE_METHOD") // Invoked reflectively by Guice
     private ActorRef provideClusterEmitter(final Injector injector, final ActorSystem system) {
+        return launchEmitter(injector, system, _configuration.getClusterPipelineConfiguration(), "cluster-emitter-configurator");
+    }
+
+    @Provides
+    @Singleton
+    @Named("host-emitter")
+    @SuppressFBWarnings("UPM_UNCALLED_PRIVATE_METHOD") // Invoked reflectively by Guice
+    private ActorRef provideHostEmitter(final Injector injector, final ActorSystem system) {
+        return launchEmitter(injector, system, _configuration.getHostPipelineConfiguration(), "host-emitter-configurator");
+    }
+
+    private ActorRef launchEmitter(final Injector injector, final ActorSystem system, final File pipelineFile, final String name) {
         final ActorRef emitterConfigurationProxy = system.actorOf(
                 ConfigurableActorProxy.props(new RoundRobinEmitterFactory()),
-                "cluster-emitter-configurator");
+                name);
         final ActorConfigurator<EmitterConfiguration> configurator =
                 new ActorConfigurator<>(emitterConfigurationProxy, EmitterConfiguration.class);
         final ObjectMapper objectMapper = EmitterConfiguration.createObjectMapper(injector);
-        final File configurationFile = _configuration.getClusterPipelineConfiguration();
         final Builder<? extends JsonNodeSource> sourceBuilder;
-        if (configurationFile.getName().toLowerCase(Locale.getDefault()).endsWith(HOCON_FILE_EXTENSION)) {
+        if (pipelineFile.getName().toLowerCase(Locale.getDefault()).endsWith(HOCON_FILE_EXTENSION)) {
             sourceBuilder = new HoconFileSource.Builder()
                     .setObjectMapper(objectMapper)
-                    .setFile(configurationFile);
+                    .setFile(pipelineFile);
         } else {
             sourceBuilder = new JsonNodeFileSource.Builder()
                     .setObjectMapper(objectMapper)
-                    .setFile(configurationFile);
+                    .setFile(pipelineFile);
         }
 
         final DynamicConfiguration configuration = new DynamicConfiguration.Builder()
                 .setObjectMapper(objectMapper)
                 .addSourceBuilder(sourceBuilder)
-                .addTrigger(new FileTrigger.Builder().setFile(_configuration.getClusterPipelineConfiguration()).build())
-                .addListener(configurator)
-                .build();
-
-        configuration.launch();
-
-        return emitterConfigurationProxy;
-    }
-
-    @Provides
-    @Singleton
-    @Named("host-emitter")
-    @SuppressFBWarnings("UPM_UNCALLED_PRIVATE_METHOD") // Invoked reflectively by Guice
-    private ActorRef provideHostEmitter(final Injector injector, final ActorSystem system) {
-        final ActorRef emitterConfigurationProxy = system.actorOf(
-                ConfigurableActorProxy.props(new RoundRobinEmitterFactory()),
-                "host-emitter-configurator");
-        final ActorConfigurator<EmitterConfiguration> configurator =
-                new ActorConfigurator<>(emitterConfigurationProxy, EmitterConfiguration.class);
-        final ObjectMapper objectMapper = EmitterConfiguration.createObjectMapper(injector);
-        final DynamicConfiguration configuration = new DynamicConfiguration.Builder()
-                .setObjectMapper(objectMapper)
-                .addSourceBuilder(
-                        new JsonNodeFileSource.Builder()
-                                .setObjectMapper(objectMapper)
-                                .setFile(_configuration.getHostPipelineConfiguration()))
-                .addTrigger(new FileTrigger.Builder().setFile(_configuration.getHostPipelineConfiguration()).build())
+                .addTrigger(new FileTrigger.Builder().setFile(pipelineFile).build())
                 .addListener(configurator)
                 .build();
 
@@ -259,6 +244,14 @@ private ActorRef provideTcpServer(final Injector injector, final ActorSystem sys
         return system.actorOf(GuiceActorCreator.props(injector, AggClientServer.class), "tcp-server");
     }
 
+    @Provides
+    @Singleton
+    @Named("cluster-joiner")
+    @SuppressFBWarnings("UPM_UNCALLED_PRIVATE_METHOD") // Invoked reflectively by Guice
+    private ActorRef provideClusterJoiner(final ActorSystem system, final ClusterAggregatorConfiguration config) {
+        return system.actorOf(config.getClusterJoinActor(), "cluster-joiner");
+    }
+
     @Provides
     @Singleton
     @Named("aggregator-lifecycle")

src/main/java/com/arpnetworking/clusteraggregator/Main.java

@@ -196,6 +196,11 @@ private void launchActors(final Injector injector) {
                 .log();
         injector.getInstance(Key.get(ActorRef.class, Names.named("jvm-metrics-collector")));
 
+        LOGGER.info()
+                .setMessage("Launching cluster joiner")
+                .log();
+        injector.getInstance(Key.get(ActorRef.class, Names.named("cluster-joiner")));
+
         LOGGER.info()
                 .setMessage("Launching http server")
                 .log();