org.apache.kafka.connect.runtime.rest.RestServer Maven / Gradle / Ivy
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* 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.
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package org.apache.kafka.connect.runtime.rest;
import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
import org.apache.kafka.common.config.ConfigException;
import org.apache.kafka.common.utils.Utils;
import org.apache.kafka.connect.errors.ConnectException;
import org.apache.kafka.connect.health.ConnectClusterDetails;
import org.apache.kafka.connect.rest.ConnectRestExtension;
import org.apache.kafka.connect.rest.ConnectRestExtensionContext;
import org.apache.kafka.connect.runtime.Herder;
import org.apache.kafka.connect.runtime.WorkerConfig;
import org.apache.kafka.connect.runtime.health.ConnectClusterDetailsImpl;
import org.apache.kafka.connect.runtime.health.ConnectClusterStateImpl;
import org.apache.kafka.connect.runtime.rest.errors.ConnectExceptionMapper;
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.LoggingResource;
import org.apache.kafka.connect.runtime.rest.resources.RootResource;
import org.apache.kafka.connect.runtime.rest.util.SSLUtils;
import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.CustomRequestLog;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.server.Slf4jRequestLogWriter;
import org.eclipse.jetty.server.handler.ContextHandlerCollection;
import org.eclipse.jetty.server.handler.DefaultHandler;
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.eclipse.jetty.servlets.HeaderFilter;
import org.eclipse.jetty.util.ssl.SslContextFactory;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.ServerProperties;
import org.glassfish.jersey.servlet.ServletContainer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.DispatcherType;
import javax.ws.rs.core.UriBuilder;
import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import static org.apache.kafka.connect.runtime.WorkerConfig.ADMIN_LISTENERS_HTTPS_CONFIGS_PREFIX;
/**
* 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);
// Used to distinguish between Admin connectors and regular REST API connectors when binding admin handlers
private static final String ADMIN_SERVER_CONNECTOR_NAME = "Admin";
private static final Pattern LISTENER_PATTERN = Pattern.compile("^(.*)://\\[?([0-9a-zA-Z\\-%._:]*)\\]?:(-?[0-9]+)");
private static final long GRACEFUL_SHUTDOWN_TIMEOUT_MS = 60 * 1000;
private static final String PROTOCOL_HTTP = "http";
private static final String PROTOCOL_HTTPS = "https";
private final WorkerConfig config;
private ContextHandlerCollection handlers;
private Server jettyServer;
private List connectRestExtensions = Collections.emptyList();
/**
* Create a REST server for this herder using the specified configs.
*/
public RestServer(WorkerConfig config) {
this.config = config;
List listeners = config.getList(WorkerConfig.LISTENERS_CONFIG);
List adminListeners = config.getList(WorkerConfig.ADMIN_LISTENERS_CONFIG);
jettyServer = new Server();
handlers = new ContextHandlerCollection();
createConnectors(listeners, adminListeners);
}
/**
* Adds Jetty connector for each configured listener
*/
public void createConnectors(List listeners, List adminListeners) {
List connectors = new ArrayList<>();
for (String listener : listeners) {
Connector connector = createConnector(listener);
connectors.add(connector);
log.info("Added connector for {}", listener);
}
jettyServer.setConnectors(connectors.toArray(new Connector[0]));
if (adminListeners != null && !adminListeners.isEmpty()) {
for (String adminListener : adminListeners) {
Connector conn = createConnector(adminListener, true);
jettyServer.addConnector(conn);
log.info("Added admin connector for {}", adminListener);
}
}
}
/**
* Creates regular (non-admin) Jetty connector according to configuration
*/
public Connector createConnector(String listener) {
return createConnector(listener, false);
}
/**
* Creates Jetty connector according to configuration
*/
public Connector createConnector(String listener, boolean isAdmin) {
Matcher listenerMatcher = LISTENER_PATTERN.matcher(listener);
if (!listenerMatcher.matches())
throw new ConfigException("Listener doesn't have the right format (protocol://hostname:port).");
String protocol = listenerMatcher.group(1).toLowerCase(Locale.ENGLISH);
if (!PROTOCOL_HTTP.equals(protocol) && !PROTOCOL_HTTPS.equals(protocol))
throw new ConfigException(String.format("Listener protocol must be either \"%s\" or \"%s\".", PROTOCOL_HTTP, PROTOCOL_HTTPS));
String hostname = listenerMatcher.group(2);
int port = Integer.parseInt(listenerMatcher.group(3));
ServerConnector connector;
if (PROTOCOL_HTTPS.equals(protocol)) {
SslContextFactory ssl;
if (isAdmin) {
ssl = SSLUtils.createServerSideSslContextFactory(config, ADMIN_LISTENERS_HTTPS_CONFIGS_PREFIX);
} else {
ssl = SSLUtils.createServerSideSslContextFactory(config);
}
connector = new ServerConnector(jettyServer, ssl);
if (!isAdmin) {
connector.setName(String.format("%s_%s%d", PROTOCOL_HTTPS, hostname, port));
}
} else {
connector = new ServerConnector(jettyServer);
if (!isAdmin) {
connector.setName(String.format("%s_%s%d", PROTOCOL_HTTP, hostname, port));
}
}
if (isAdmin) {
connector.setName(ADMIN_SERVER_CONNECTOR_NAME);
}
if (!hostname.isEmpty())
connector.setHost(hostname);
connector.setPort(port);
return connector;
}
public void initializeServer() {
log.info("Initializing REST server");
/* 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 initialize REST server", e);
}
log.info("REST server listening at " + jettyServer.getURI() + ", advertising URL " + advertisedUrl());
log.info("REST admin endpoints at " + adminUrl());
}
public void initializeResources(Herder herder) {
log.info("Initializing REST resources");
ResourceConfig resourceConfig = new ResourceConfig();
resourceConfig.register(new JacksonJsonProvider());
resourceConfig.register(new RootResource(herder));
resourceConfig.register(new ConnectorsResource(herder, config));
resourceConfig.register(new ConnectorPluginsResource(herder));
resourceConfig.register(ConnectExceptionMapper.class);
resourceConfig.property(ServerProperties.WADL_FEATURE_DISABLE, true);
registerRestExtensions(herder, resourceConfig);
List adminListeners = config.getList(WorkerConfig.ADMIN_LISTENERS_CONFIG);
ResourceConfig adminResourceConfig;
if (adminListeners == null) {
log.info("Adding admin resources to main listener");
adminResourceConfig = resourceConfig;
adminResourceConfig.register(new LoggingResource());
} else if (adminListeners.size() > 0) {
// TODO: we need to check if these listeners are same as 'listeners'
// TODO: the following code assumes that they are different
log.info("Adding admin resources to admin listener");
adminResourceConfig = new ResourceConfig();
adminResourceConfig.register(new JacksonJsonProvider());
adminResourceConfig.register(new LoggingResource());
adminResourceConfig.register(ConnectExceptionMapper.class);
} else {
log.info("Skipping adding admin resources");
// set up adminResource but add no handlers to it
adminResourceConfig = resourceConfig;
}
ServletContainer servletContainer = new ServletContainer(resourceConfig);
ServletHolder servletHolder = new ServletHolder(servletContainer);
List contextHandlers = new ArrayList<>();
ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
context.setContextPath("/");
context.addServlet(servletHolder, "/*");
contextHandlers.add(context);
ServletContextHandler adminContext = null;
if (adminResourceConfig != resourceConfig) {
adminContext = new ServletContextHandler(ServletContextHandler.SESSIONS);
ServletHolder adminServletHolder = new ServletHolder(new ServletContainer(adminResourceConfig));
adminContext.setContextPath("/");
adminContext.addServlet(adminServletHolder, "/*");
adminContext.setVirtualHosts(new String[]{"@" + ADMIN_SERVER_CONNECTOR_NAME});
contextHandlers.add(adminContext);
}
String allowedOrigins = config.getString(WorkerConfig.ACCESS_CONTROL_ALLOW_ORIGIN_CONFIG);
if (!Utils.isBlank(allowedOrigins)) {
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 (!Utils.isBlank(allowedMethods)) {
filterHolder.setInitParameter(CrossOriginFilter.ALLOWED_METHODS_PARAM, allowedMethods);
}
context.addFilter(filterHolder, "/*", EnumSet.of(DispatcherType.REQUEST));
}
String headerConfig = config.getString(WorkerConfig.RESPONSE_HTTP_HEADERS_CONFIG);
if (!Utils.isBlank(headerConfig)) {
configureHttpResponsHeaderFilter(context);
}
RequestLogHandler requestLogHandler = new RequestLogHandler();
Slf4jRequestLogWriter slf4jRequestLogWriter = new Slf4jRequestLogWriter();
slf4jRequestLogWriter.setLoggerName(RestServer.class.getCanonicalName());
CustomRequestLog requestLog = new CustomRequestLog(slf4jRequestLogWriter, CustomRequestLog.EXTENDED_NCSA_FORMAT + " %{ms}T");
requestLogHandler.setRequestLog(requestLog);
contextHandlers.add(new DefaultHandler());
contextHandlers.add(requestLogHandler);
handlers.setHandlers(contextHandlers.toArray(new Handler[0]));
try {
context.start();
} catch (Exception e) {
throw new ConnectException("Unable to initialize REST resources", e);
}
if (adminResourceConfig != resourceConfig) {
try {
log.debug("Starting admin context");
adminContext.start();
} catch (Exception e) {
throw new ConnectException("Unable to initialize Admin REST resources", e);
}
}
log.info("REST resources initialized; server is started and ready to handle requests");
}
public URI serverUrl() {
return jettyServer.getURI();
}
public void stop() {
log.info("Stopping REST server");
try {
for (ConnectRestExtension connectRestExtension : connectRestExtensions) {
try {
connectRestExtension.close();
} catch (IOException e) {
log.warn("Error while invoking close on " + connectRestExtension.getClass(), e);
}
}
jettyServer.stop();
jettyServer.join();
} catch (Exception e) {
jettyServer.destroy();
throw new ConnectException("Unable to stop REST server", e);
}
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. {@link #initializeServer()}
* must be invoked successfully before calling this method.
*/
public URI advertisedUrl() {
UriBuilder builder = UriBuilder.fromUri(jettyServer.getURI());
String advertisedSecurityProtocol = determineAdvertisedProtocol();
ServerConnector serverConnector = findConnector(advertisedSecurityProtocol);
builder.scheme(advertisedSecurityProtocol);
String advertisedHostname = config.getString(WorkerConfig.REST_ADVERTISED_HOST_NAME_CONFIG);
if (advertisedHostname != null && !advertisedHostname.isEmpty())
builder.host(advertisedHostname);
else if (serverConnector != null && serverConnector.getHost() != null && serverConnector.getHost().length() > 0)
builder.host(serverConnector.getHost());
Integer advertisedPort = config.getInt(WorkerConfig.REST_ADVERTISED_PORT_CONFIG);
if (advertisedPort != null)
builder.port(advertisedPort);
else if (serverConnector != null && serverConnector.getPort() > 0)
builder.port(serverConnector.getPort());
log.info("Advertised URI: {}", builder.build());
return builder.build();
}
/**
* @return the admin url for this worker. can be null if admin endpoints are disabled.
*/
public URI adminUrl() {
ServerConnector adminConnector = null;
for (Connector connector : jettyServer.getConnectors()) {
if (ADMIN_SERVER_CONNECTOR_NAME.equals(connector.getName()))
adminConnector = (ServerConnector) connector;
}
if (adminConnector == null) {
List adminListeners = config.getList(WorkerConfig.ADMIN_LISTENERS_CONFIG);
if (adminListeners == null) {
return advertisedUrl();
} else if (adminListeners.isEmpty()) {
return null;
} else {
log.error("No admin connector found for listeners {}", adminListeners);
return null;
}
}
UriBuilder builder = UriBuilder.fromUri(jettyServer.getURI());
builder.port(adminConnector.getLocalPort());
return builder.build();
}
String determineAdvertisedProtocol() {
String advertisedSecurityProtocol = config.getString(WorkerConfig.REST_ADVERTISED_LISTENER_CONFIG);
if (advertisedSecurityProtocol == null) {
String listeners = (String) config.originals().get(WorkerConfig.LISTENERS_CONFIG);
if (listeners == null)
return PROTOCOL_HTTP;
else
listeners = listeners.toLowerCase(Locale.ENGLISH);
if (listeners.contains(String.format("%s://", PROTOCOL_HTTP)))
return PROTOCOL_HTTP;
else if (listeners.contains(String.format("%s://", PROTOCOL_HTTPS)))
return PROTOCOL_HTTPS;
else
return PROTOCOL_HTTP;
} else {
return advertisedSecurityProtocol.toLowerCase(Locale.ENGLISH);
}
}
/**
* Locate a Jetty connector for the standard (non-admin) REST API that uses the given protocol.
* @param protocol the protocol for the connector (e.g., "http" or "https").
* @return a {@link ServerConnector} for the server that uses the requested protocol, or
* {@code null} if none exist.
*/
ServerConnector findConnector(String protocol) {
for (Connector connector : jettyServer.getConnectors()) {
String connectorName = connector.getName();
// We set the names for these connectors when instantiating them, beginning with the
// protocol for the connector and then an underscore ("_"). We rely on that format here
// when trying to locate a connector with the requested protocol; if the naming format
// for the connectors we create is ever changed, we'll need to adjust the logic here
// accordingly.
if (connectorName.startsWith(protocol + "_") && !ADMIN_SERVER_CONNECTOR_NAME.equals(connectorName))
return (ServerConnector) connector;
}
return null;
}
void registerRestExtensions(Herder herder, ResourceConfig resourceConfig) {
connectRestExtensions = herder.plugins().newPlugins(
config.getList(WorkerConfig.REST_EXTENSION_CLASSES_CONFIG),
config, ConnectRestExtension.class);
long herderRequestTimeoutMs = ConnectorsResource.REQUEST_TIMEOUT_MS;
Integer rebalanceTimeoutMs = config.getRebalanceTimeout();
if (rebalanceTimeoutMs != null) {
herderRequestTimeoutMs = Math.min(herderRequestTimeoutMs, rebalanceTimeoutMs.longValue());
}
ConnectClusterDetails connectClusterDetails = new ConnectClusterDetailsImpl(
herder.kafkaClusterId()
);
ConnectRestExtensionContext connectRestExtensionContext =
new ConnectRestExtensionContextImpl(
new ConnectRestConfigurable(resourceConfig),
new ConnectClusterStateImpl(herderRequestTimeoutMs, connectClusterDetails, herder)
);
for (ConnectRestExtension connectRestExtension : connectRestExtensions) {
connectRestExtension.register(connectRestExtensionContext);
}
}
/**
* Register header filter to ServletContextHandler.
* @param context The serverlet context handler
*/
protected void configureHttpResponsHeaderFilter(ServletContextHandler context) {
String headerConfig = config.getString(WorkerConfig.RESPONSE_HTTP_HEADERS_CONFIG);
FilterHolder headerFilterHolder = new FilterHolder(HeaderFilter.class);
headerFilterHolder.setInitParameter("headerConfig", headerConfig);
context.addFilter(headerFilterHolder, "/*", EnumSet.of(DispatcherType.REQUEST));
}
}
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