src/main/java/org/apache/cassandra/sidecar/MainModule.java

/*
 * 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.cassandra.sidecar;

import com.google.inject.AbstractModule;
import com.google.inject.Provides;
import com.google.inject.Singleton;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.core.http.HttpServer;
import io.vertx.core.http.HttpServerOptions;
import io.vertx.ext.dropwizard.DropwizardMetricsOptions;
import io.vertx.ext.web.Router;
import io.vertx.ext.web.handler.LoggerHandler;
import io.vertx.ext.web.handler.StaticHandler;
import org.apache.cassandra.sidecar.routes.HealthCheck;
import org.apache.cassandra.sidecar.routes.HealthService;
import org.apache.commons.configuration2.YAMLConfiguration;
import org.apache.commons.configuration2.builder.fluent.Configurations;
import org.apache.commons.configuration2.ex.ConfigurationException;

import java.io.File;

public class MainModule extends AbstractModule
{
    @Override
    protected void configure()
    {
        bind(CassandraSidecarDaemon.class).in(Singleton.class);
    }

    @Provides
    @Singleton
    public Vertx getVertx()
    {
        return Vertx.vertx(new VertxOptions().setMetricsOptions(
                new DropwizardMetricsOptions()
                        .setEnabled(true)
                        .setJmxEnabled(true)
                        .setJmxDomain("cassandra-sidecar-metrics")
        ));
    }

    @Provides
    @Singleton
    public HealthService healthService(Configuration config)
    {
        return new HealthService(config.getHealthCheckFrequencyMillis(),
                new HealthCheck(config.getCassandraHost(), config.getCassandraPort()));
    }

    @Provides
    @Singleton
    public HttpServer vertxServer(Vertx vertx, Configuration config, Router router)
    {
        HttpServer server = vertx.createHttpServer(new HttpServerOptions()
                .setPort(config.getPort())
                .setLogActivity(true));
        server.requestHandler(router);
        return server;
    }

    @Provides
    @Singleton
    public Router vertxRouter(Vertx vertx, HealthService healthService)
    {
        Router router = Router.router(vertx);
        router.route().handler(LoggerHandler.create());

        // include docs generated into src/main/resources/docs
        StaticHandler swagger = StaticHandler.create()
                                             .setWebRoot("docs")
                                             .setCachingEnabled(false);
        router.route().path("/docs/*").handler(swagger);

        // API paths
        router.route().path("/api/v1/__health").handler(healthService::handleHealth);
        return router;
    }

    @Provides
    @Singleton
    public Configuration configuration() throws ConfigurationException
    {
        Configurations confs = new Configurations();
        File propFile = new File("sidecar.yaml");
        YAMLConfiguration yamlConf = confs.fileBased(YAMLConfiguration.class, propFile);

        return new Configuration(
                yamlConf.get(String.class, "cassandra.host"),
                yamlConf.get(Integer.class, "cassandra.port"),
                yamlConf.get(Integer.class, "sidecar.port"),
                yamlConf.get(Integer.class, "healthcheck.poll_freq_millis"));
    }
}