/*
* 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.stratos.load.balancer.conf.configurator;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.stratos.load.balancer.conf.LoadBalancerConfiguration;
import org.apache.stratos.load.balancer.conf.domain.Algorithm;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.wso2.carbon.utils.CarbonUtils;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* Synapse configurator to configure Synapse settings required for the load balancer.
*/
public class SynapseConfigurator {
private static final Log log = LogFactory.getLog(SynapseConfigurator.class);
/**
* Configure Synapse using load balancer configuration.
*
* @param configuration
*/
public static void configure(LoadBalancerConfiguration configuration) {
configureMainSequence(configuration);
}
/**
* Configure main sequence send mediator endpoint.
*
* @param configuration Load balancer configuration.
*/
public static void configureMainSequence(LoadBalancerConfiguration configuration) {
String filePath = CarbonUtils.getCarbonHome() + File.separator + "repository" + File.separator + "deployment" + File.separator + "server" + File.separator
+ "synapse-configs" + File.separator + "default" + File.separator + "sequences" + File.separator + "main.xml";
configureMainSequence(configuration, filePath, filePath);
}
/**
* Configure main sequence send mediator endpoint.
*
* @param configuration Load balancer configuration.
* @param inputFilePath Input file path.
* @param outputFilePath Output file path.
*/
public static void configureMainSequence(LoadBalancerConfiguration configuration, String inputFilePath, String outputFilePath) {
try {
if (log.isInfoEnabled()) {
log.info("Configuring synapse main sequence...");
}
if (log.isDebugEnabled()) {
log.debug(String.format("Reading synapse main sequence: %s", inputFilePath));
}
File inputFile = new File(inputFilePath);
if (!inputFile.exists()) {
throw new RuntimeException(String.format("File not found: %s", inputFilePath));
}
FileInputStream file = new FileInputStream(inputFile);
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document xmlDocument = builder.parse(file);
XPath xPath = XPathFactory.newInstance().newXPath();
String expression = "/sequence/in/send/endpoint/class/parameter";
if (log.isDebugEnabled()) {
log.debug(String.format("xpath expression = %s", expression));
}
boolean updated = false;
NodeList nodeList = (NodeList) xPath.compile(expression).evaluate(xmlDocument, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);
Node parameter = node.getAttributes().getNamedItem("name");
if (parameter.getNodeValue().equals("algorithmClassName")) {
String defaultAlgorithmName = configuration.getDefaultAlgorithmName();
if (StringUtils.isBlank(defaultAlgorithmName)) {
throw new RuntimeException("Default algorithm name not found in load balancer configuration");
}
Algorithm defaultAlgorithm = configuration.getAlgorithm(defaultAlgorithmName);
if (defaultAlgorithm == null) {
throw new RuntimeException("Default algorithm not found in load balancer configuration");
}
String algorithmClassName = defaultAlgorithm.getClassName();
if (log.isDebugEnabled()) {
log.debug(String.format("Setting algorithm-class-name = %s", algorithmClassName));
}
node.setTextContent(algorithmClassName);
updated = true;
} else if (parameter.getNodeValue().equals("failover")) {
String value = String.valueOf(configuration.isFailOverEnabled());
if (log.isDebugEnabled()) {
log.debug(String.format("Setting failover = %s", value));
}
node.setTextContent(value);
updated = true;
} else if (parameter.getNodeValue().equals("sessionAffinity")) {
String value = String.valueOf(configuration.isSessionAffinityEnabled());
if (log.isDebugEnabled()) {
log.debug(String.format("Setting session-affinity = %s", value));
}
node.setTextContent(value);
updated = true;
} else if (parameter.getNodeValue().equals("sessionTimeout")) {
String value = String.valueOf(configuration.getSessionTimeout());
if (log.isDebugEnabled()) {
log.debug(String.format("Setting session-timeout = %s", value));
}
node.setTextContent(value);
updated = true;
}
}
if (updated) {
if (log.isDebugEnabled()) {
log.debug(String.format("Updating synapse main sequence: %s", outputFilePath));
}
write(xmlDocument, outputFilePath);
if (log.isInfoEnabled()) {
log.info("Synapse main sequence configured successfully");
}
} else {
throw new RuntimeException(String.format("Send mediator endpoint configuration not found: %s", inputFilePath));
}
} catch (Exception e) {
throw new RuntimeException("Could not configure synapse settings", e);
}
}
/**
* Write xml document to file.
*
* @param document
* @param outputFilePath
* @throws IOException
*/
private static void write(Document document, String outputFilePath) throws IOException {
try {
Transformer transformer = TransformerFactory.newInstance().newTransformer();
DocumentType documentType = document.getDoctype();
if (documentType != null) {
String publicId = documentType.getPublicId();
if (publicId != null) {
transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, publicId);
}
transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, documentType.getSystemId());
}
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
Source source = new DOMSource(document);
FileOutputStream outputStream = new FileOutputStream(outputFilePath);
Result result = new StreamResult(outputStream);
transformer.transform(source, result);
} catch (Exception e) {
throw new RuntimeException(String.format("Could not write xml file: s%", outputFilePath), e);
}
}
}