software/webapp/src/main/java/org/apache/brooklyn/entity/webapp/nodejs/NodeJsWebAppServiceImpl.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.brooklyn.entity.webapp.nodejs;

import org.apache.brooklyn.core.entity.Attributes;
import org.apache.brooklyn.core.feed.ConfigToAttributes;
import org.apache.brooklyn.core.location.access.BrooklynAccessUtils;
import org.apache.brooklyn.entity.software.base.SoftwareProcessImpl;
import org.apache.brooklyn.entity.webapp.WebAppServiceMethods;
import org.apache.brooklyn.feed.http.HttpFeed;
import org.apache.brooklyn.feed.http.HttpPollConfig;
import org.apache.brooklyn.feed.http.HttpValueFunctions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Predicates;
import com.google.common.net.HostAndPort;

public class NodeJsWebAppServiceImpl extends SoftwareProcessImpl implements NodeJsWebAppService {

    private static final Logger LOG = LoggerFactory.getLogger(NodeJsWebAppService.class);

    private transient HttpFeed httpFeed;

    @Override
    public Class<?> getDriverInterface() {
        return NodeJsWebAppDriver.class;
    }

    @Override
    public NodeJsWebAppDriver getDriver() {
        return (NodeJsWebAppDriver) super.getDriver();
    }

    @Override
    protected void connectSensors() {
        super.connectSensors();

        ConfigToAttributes.apply(this);

        HostAndPort accessible = BrooklynAccessUtils.getBrooklynAccessibleAddress(this, getHttpPort());
        String nodeJsUrl = String.format("http://%s:%d", accessible.getHostText(), accessible.getPort());

        if (isHttpMonitoringEnabled()) {
            LOG.info("Connecting to {}", nodeJsUrl);
            
            httpFeed = HttpFeed.builder()
                    .entity(this)
                    .baseUri(nodeJsUrl)
                    .poll(new HttpPollConfig<Boolean>(SERVICE_UP)
                            .suppressDuplicates(true)
                            .suburl(getConfig(NodeJsWebAppService.SERVICE_UP_PATH))
                            .checkSuccess(Predicates.alwaysTrue())
                            .onSuccess(HttpValueFunctions.responseCodeEquals(200))
                            .setOnException(false))
                    .build();
            
        } else {
            connectServiceUpIsRunning();
        }

        WebAppServiceMethods.connectWebAppServerPolicies(this);
    }

    @Override
    public void disconnectSensors() {
        if (httpFeed != null) httpFeed.stop();
        disconnectServiceUpIsRunning();
        super.disconnectSensors();
    }

    @Override
    protected void postStop() {
        super.postStop();

        sensors().set(REQUESTS_PER_SECOND_LAST, 0D);
        sensors().set(REQUESTS_PER_SECOND_IN_WINDOW, 0D);
    }
    
    protected boolean isHttpMonitoringEnabled() {
        return Boolean.TRUE.equals(getConfig(USE_HTTP_MONITORING));
    }
    
    @Override
    public Integer getHttpPort() { return getAttribute(Attributes.HTTP_PORT); }

}