private static void installCrawler(String distDir, File installBasePath, CrawlerConfig crawlerConfig, IndexerConfig indexerConfig) throws IOException {
logger.info("installing crawler");
TarUtil.untarFile(FileUtil.getExistingFile(distDir+"/crawler.tgz", true, false, false), installBasePath);
doCommonTasks(new File(installBasePath,"/crawler"), crawlerConfig);
Config indexerModuleProperties = Config.getConfig("indexerModule.properties");
indexerModuleProperties.set("remoteRmiIndexer.host", indexerConfig.installOnHost + ":" + indexerConfig.installOnBasePort);
indexerModuleProperties.modifyOnDisk(new File(installBasePath,"/crawler/conf/indexerModule.properties"));
configureCrawler(new File(installBasePath, "crawler"), crawlerConfig);
}