spring-boot-starter-data-jest/src/main/java/com/github/vanroy/springboot/autoconfigure/data/jest/ElasticsearchJestAutoConfiguration.java
private int createInternalNode() throws NodeValidationException {

		if (logger.isInfoEnabled()) {
			logger.info("Create test ES node");
		}

		int port = SocketUtils.findAvailableTcpPort();
		String clusterName = INTERNAL_TEST_CLUSTER_NAME + UUID.randomUUID();

		Settings.Builder settingsBuilder = Settings.builder()
				.put("cluster.name", clusterName)
				.put("http.type", "netty4")
				.put("http.port", String.valueOf(port));

		if (this.esNodeproperties != null) {
			this.esNodeproperties.getProperties().forEach(settingsBuilder::put);
		}

		Collection<Class<? extends Plugin>> plugins = scanPlugins();
		plugins.add(Netty4Plugin.class);

		this.node = new InternalNode(settingsBuilder.build(), plugins).start();

		return Integer.parseInt(settingsBuilder.get("http.port"));
	}
private int createInternalNode() throws NodeValidationException {

		if (logger.isInfoEnabled()) {
			logger.info("Create test ES node");
		}

		int port = SocketUtils.findAvailableTcpPort();
		String clusterName = INTERNAL_TEST_CLUSTER_NAME + UUID.randomUUID();

		Settings.Builder settingsBuilder = Settings.builder()
				.put("cluster.name", clusterName)
				.put("http.type", "netty4")
				.put("http.port", String.valueOf(port));

		if (this.esNodeproperties != null) {
			this.esNodeproperties.getProperties().forEach(settingsBuilder::put);
		}

		Collection<Class<? extends Plugin>> plugins = scanPlugins();
		plugins.add(Netty4Plugin.class);

		this.node = new InternalNode(settingsBuilder.build(), plugins).start();

		return Integer.parseInt(settingsBuilder.get("http.port"));
	}
Create internal Elasticsearch node.
@return HTTP port of node