/*
* 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.kafka.connect.runtime.rest;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
import org.apache.kafka.connect.errors.ConnectException;
import org.apache.kafka.connect.runtime.Herder;
import org.apache.kafka.connect.runtime.WorkerConfig;
import org.apache.kafka.connect.runtime.rest.entities.ErrorMessage;
import org.apache.kafka.connect.runtime.rest.errors.ConnectExceptionMapper;
import org.apache.kafka.connect.runtime.rest.errors.ConnectRestException;
import org.apache.kafka.connect.runtime.rest.resources.ConnectorPluginsResource;
import org.apache.kafka.connect.runtime.rest.resources.ConnectorsResource;
import org.apache.kafka.connect.runtime.rest.resources.RootResource;
import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.server.Slf4jRequestLog;
import org.eclipse.jetty.server.handler.DefaultHandler;
import org.eclipse.jetty.server.handler.HandlerCollection;
import org.eclipse.jetty.server.handler.RequestLogHandler;
import org.eclipse.jetty.server.handler.StatisticsHandler;
import org.eclipse.jetty.servlet.FilterHolder;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.servlets.CrossOriginFilter;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.servlet.ServletContainer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.EnumSet;
import java.util.List;
import java.util.Map;
import javax.servlet.DispatcherType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriBuilder;
/**
* Embedded server for the REST API that provides the control plane for Kafka Connect workers.
*/
public class RestServer {
private static final Logger log = LoggerFactory.getLogger(RestServer.class);
private static final long GRACEFUL_SHUTDOWN_TIMEOUT_MS = 60 * 1000;
private static final ObjectMapper JSON_SERDE = new ObjectMapper();
private final WorkerConfig config;
private Server jettyServer;
/**
* Create a REST server for this herder using the specified configs.
*/
public RestServer(WorkerConfig config) {
this.config = config;
// To make the advertised port available immediately, we need to do some configuration here
String hostname = config.getString(WorkerConfig.REST_HOST_NAME_CONFIG);
Integer port = config.getInt(WorkerConfig.REST_PORT_CONFIG);
jettyServer = new Server();
ServerConnector connector = new ServerConnector(jettyServer);
if (hostname != null && !hostname.isEmpty())
connector.setHost(hostname);
connector.setPort(port);
jettyServer.setConnectors(new Connector[]{connector});
}
public void start(Herder herder) {
log.info("Starting REST server");
ResourceConfig resourceConfig = new ResourceConfig();
resourceConfig.register(new JacksonJsonProvider());
resourceConfig.register(RootResource.class);
resourceConfig.register(new ConnectorsResource(herder));
resourceConfig.register(new ConnectorPluginsResource(herder));
resourceConfig.register(ConnectExceptionMapper.class);
ServletContainer servletContainer = new ServletContainer(resourceConfig);
ServletHolder servletHolder = new ServletHolder(servletContainer);
ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
context.setContextPath("/");
context.addServlet(servletHolder, "/*");
String allowedOrigins = config.getString(WorkerConfig.ACCESS_CONTROL_ALLOW_ORIGIN_CONFIG);
if (allowedOrigins != null && !allowedOrigins.trim().isEmpty()) {
FilterHolder filterHolder = new FilterHolder(new CrossOriginFilter());
filterHolder.setName("cross-origin");
filterHolder.setInitParameter(CrossOriginFilter.ALLOWED_ORIGINS_PARAM, allowedOrigins);
String allowedMethods = config.getString(WorkerConfig.ACCESS_CONTROL_ALLOW_METHODS_CONFIG);
if (allowedMethods != null && !allowedOrigins.trim().isEmpty()) {
filterHolder.setInitParameter(CrossOriginFilter.ALLOWED_METHODS_PARAM, allowedMethods);
}
context.addFilter(filterHolder, "/*", EnumSet.of(DispatcherType.REQUEST));
}
RequestLogHandler requestLogHandler = new RequestLogHandler();
Slf4jRequestLog requestLog = new Slf4jRequestLog();
requestLog.setLoggerName(RestServer.class.getCanonicalName());
requestLog.setLogLatency(true);
requestLogHandler.setRequestLog(requestLog);
HandlerCollection handlers = new HandlerCollection();
handlers.setHandlers(new Handler[]{context, new DefaultHandler(), requestLogHandler});
/* Needed for graceful shutdown as per `setStopTimeout` documentation */
StatisticsHandler statsHandler = new StatisticsHandler();
statsHandler.setHandler(handlers);
jettyServer.setHandler(statsHandler);
jettyServer.setStopTimeout(GRACEFUL_SHUTDOWN_TIMEOUT_MS);
jettyServer.setStopAtShutdown(true);
try {
jettyServer.start();
} catch (Exception e) {
throw new ConnectException("Unable to start REST server", e);
}
log.info("REST server listening at " + jettyServer.getURI() + ", advertising URL " + advertisedUrl());
}
public void stop() {
log.info("Stopping REST server");
try {
jettyServer.stop();
jettyServer.join();
} catch (Exception e) {
throw new ConnectException("Unable to stop REST server", e);
} finally {
jettyServer.destroy();
}
log.info("REST server stopped");
}
/**
* Get the URL to advertise to other workers and clients. This uses the default connector from the embedded Jetty
* server, unless overrides for advertised hostname and/or port are provided via configs.
*/
public URI advertisedUrl() {
UriBuilder builder = UriBuilder.fromUri(jettyServer.getURI());
String advertisedHostname = config.getString(WorkerConfig.REST_ADVERTISED_HOST_NAME_CONFIG);
if (advertisedHostname != null && !advertisedHostname.isEmpty())
builder.host(advertisedHostname);
Integer advertisedPort = config.getInt(WorkerConfig.REST_ADVERTISED_PORT_CONFIG);
if (advertisedPort != null)
builder.port(advertisedPort);
else
builder.port(config.getInt(WorkerConfig.REST_PORT_CONFIG));
return builder.build();
}
/**
* @param url HTTP connection will be established with this url.
* @param method HTTP method ("GET", "POST", "PUT", etc.)
* @param requestBodyData Object to serialize as JSON and send in the request body.
* @param responseFormat Expected format of the response to the HTTP request.
* @param <T> The type of the deserialized response to the HTTP request.
* @return The deserialized response to the HTTP request, or null if no data is expected.
*/
public static <T> HttpResponse<T> httpRequest(String url, String method, Object requestBodyData,
TypeReference<T> responseFormat) {
HttpURLConnection connection = null;
try {
String serializedBody = requestBodyData == null ? null : JSON_SERDE.writeValueAsString(requestBodyData);
log.debug("Sending {} with input {} to {}", method, serializedBody, url);
connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod(method);
connection.setRequestProperty("User-Agent", "kafka-connect");
connection.setRequestProperty("Accept", "application/json");
// connection.getResponseCode() implicitly calls getInputStream, so always set to true.
// On the other hand, leaving this out breaks nothing.
connection.setDoInput(true);
connection.setUseCaches(false);
if (requestBodyData != null) {
connection.setRequestProperty("Content-Type", "application/json");
connection.setDoOutput(true);
OutputStream os = connection.getOutputStream();
os.write(serializedBody.getBytes(StandardCharsets.UTF_8));
os.flush();
os.close();
}
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_NO_CONTENT) {
return new HttpResponse<>(responseCode, connection.getHeaderFields(), null);
} else if (responseCode >= 400) {
InputStream es = connection.getErrorStream();
ErrorMessage errorMessage = JSON_SERDE.readValue(es, ErrorMessage.class);
es.close();
throw new ConnectRestException(responseCode, errorMessage.errorCode(), errorMessage.message());
} else if (responseCode >= 200 && responseCode < 300) {
InputStream is = connection.getInputStream();
T result = JSON_SERDE.readValue(is, responseFormat);
is.close();
return new HttpResponse<>(responseCode, connection.getHeaderFields(), result);
} else {
throw new ConnectRestException(Response.Status.INTERNAL_SERVER_ERROR,
Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(),
"Unexpected status code when handling forwarded request: " + responseCode);
}
} catch (IOException e) {
log.error("IO error forwarding REST request: ", e);
throw new ConnectRestException(Response.Status.INTERNAL_SERVER_ERROR, "IO Error trying to forward REST request: " + e.getMessage(), e);
} finally {
if (connection != null)
connection.disconnect();
}
}
public static class HttpResponse<T> {
private int status;
private Map<String, List<String>> headers;
private T body;
public HttpResponse(int status, Map<String, List<String>> headers, T body) {
this.status = status;
this.headers = headers;
this.body = body;
}
public int status() {
return status;
}
public Map<String, List<String>> headers() {
return headers;
}
public T body() {
return body;
}
}
public static String urlJoin(String base, String path) {
if (base.endsWith("/") && path.startsWith("/"))
return base + path.substring(1);
else
return base + path;
}
}