at.ac.tuwien.dsg.cloud.utilities.messaging.discovery.LightweightSalsaDiscovery.java Source code

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Here is the source code for at.ac.tuwien.dsg.cloud.utilities.messaging.discovery.LightweightSalsaDiscovery.java

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/* 
 * Copyright 2015 Svetoslav Videnov <s.videnov@dsg.tuwien.ac.at>.
 *
 * 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 at.ac.tuwien.dsg.cloud.utilities.messaging.discovery;

import at.ac.tuwien.dsg.cloud.salsa.common.cloudservice.model.rSYBL.deploymentDescription.DeploymentDescription;
import at.ac.tuwien.dsg.cloud.salsa.common.cloudservice.model.rSYBL.deploymentDescription.DeploymentUnit;
import at.ac.tuwien.dsg.cloud.utilities.messaging.api.Discovery;
import at.ac.tuwien.dsg.cloud.utilities.messaging.lightweight.util.DiscoverySettings;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.StringReader;
import java.net.URI;
import javax.ws.rs.core.UriBuilder;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

/**
 *
 * @author Svetoslav Videnov <s.videnov@dsg.tuwien.ac.at>
 */
public class LightweightSalsaDiscovery implements Discovery {

    private DiscoverySettings config;
    private final String restCommand = "/salsa-engine/rest/services/tosca/{serviceId}/sybl";

    public LightweightSalsaDiscovery(DiscoverySettings config) {
        this.config = config;
    }

    @Override
    public String discoverHost() {
        return this.discoverHost(this.config.getServiceName());
    }

    public String discoverHost(String serviceName) {
        try {
            URI statusUri = UriBuilder.fromPath(restCommand).build(serviceName);
            HttpGet method = new HttpGet(statusUri);
            HttpHost host = new HttpHost(this.config.getIp(), this.config.getPort());
            HttpClient client = new DefaultHttpClient();
            HttpResponse response = client.execute(host, method);

            if (response.getStatusLine().getStatusCode() == 200) {
                try {
                    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
                    response.getEntity().writeTo(outputStream);
                    String serviceDescription = new String(outputStream.toByteArray());

                    JAXBContext a = JAXBContext.newInstance(DeploymentDescription.class);
                    Unmarshaller u = a.createUnmarshaller();
                    if (!serviceDescription.equalsIgnoreCase("")) {
                        Object object = u.unmarshal(new StringReader(serviceDescription));
                        DeploymentDescription deploymentInfo = (DeploymentDescription) object;

                        for (DeploymentUnit unit : deploymentInfo.getDeployments()) {
                            if (unit.getServiceUnitID().contains("RabbitServer")) {
                                return unit.getAssociatedVM().get(0).getIp();
                            }
                        }
                    }
                } catch (JAXBException e) {
                    //todo: log
                }
            }
        } catch (IOException ex) {
            //todo: log
        }

        return null;
    }
}