com.google.apphosting.runtime.jetty.ee8.EE8AppVersionHandlerFactory Maven / Gradle / Ivy
/*
* Copyright 2021 Google LLC
*
* Licensed 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
*
* https://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 com.google.apphosting.runtime.jetty.ee8;
import static com.google.apphosting.runtime.AppEngineConstants.HTTP_CONNECTOR_MODE;
import com.google.apphosting.api.ApiProxy;
import com.google.apphosting.runtime.AppEngineConstants;
import com.google.apphosting.runtime.AppVersion;
import com.google.apphosting.runtime.SessionsConfig;
import com.google.apphosting.runtime.jetty.AppVersionHandlerFactory;
import com.google.apphosting.runtime.jetty.SessionManagerHandler;
import com.google.common.flogger.GoogleLogger;
import com.google.common.html.HtmlEscapers;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspFactory;
import org.eclipse.jetty.ee8.annotations.AnnotationConfiguration;
import org.eclipse.jetty.ee8.nested.ContextHandler;
import org.eclipse.jetty.ee8.nested.Dispatcher;
import org.eclipse.jetty.ee8.quickstart.QuickStartConfiguration;
import org.eclipse.jetty.ee8.servlet.ErrorPageErrorHandler;
import org.eclipse.jetty.ee8.webapp.FragmentConfiguration;
import org.eclipse.jetty.ee8.webapp.MetaInfConfiguration;
import org.eclipse.jetty.ee8.webapp.WebAppContext;
import org.eclipse.jetty.ee8.webapp.WebInfConfiguration;
import org.eclipse.jetty.ee8.webapp.WebXmlConfiguration;
import org.eclipse.jetty.server.Server;
/**
* {@code AppVersionHandlerFactory} implements a {@code Handler} for a given {@code AppVersionKey}.
*/
public class EE8AppVersionHandlerFactory implements AppVersionHandlerFactory {
private static final GoogleLogger logger = GoogleLogger.forEnclosingClass();
private static final String TOMCAT_SIMPLE_INSTANCE_MANAGER =
"org.apache.tomcat.SimpleInstanceManager";
private static final String TOMCAT_INSTANCE_MANAGER = "org.apache.tomcat.InstanceManager";
private static final String TOMCAT_JSP_FACTORY = "org.apache.jasper.runtime.JspFactoryImpl";
/**
* Any settings in this webdefault.xml file will be inherited by all applications. We don't want
* to use Jetty's built-in webdefault.xml because we want to disable some of their functionality,
* and because we want to be explicit about what functionality we are supporting.
*/
public static final String WEB_DEFAULTS_XML =
"com/google/apphosting/runtime/jetty/webdefault.xml";
/**
* This property will be used to enable/disable Annotation Scanning when quickstart-web.xml is not
* present.
*/
private static final String USE_ANNOTATION_SCANNING = "use.annotationscanning";
/**
* A "private" request attribute to indicate if the dispatch to a most recent error page has run
* to completion. Note an error page itself may generate errors.
*/
static final String ERROR_PAGE_HANDLED = WebAppContext.ERROR_PAGE + ".handled";
private final Server server;
private final String serverInfo;
private final boolean useJettyErrorPageHandler;
public EE8AppVersionHandlerFactory(Server server, String serverInfo) {
this(server, serverInfo, false);
}
public EE8AppVersionHandlerFactory(
Server server, String serverInfo, boolean useJettyErrorPageHandler) {
this.server = server;
this.serverInfo = serverInfo;
this.useJettyErrorPageHandler = useJettyErrorPageHandler;
}
/**
* Returns the {@code Handler} that will handle requests for the specified application version.
*/
@Override
public org.eclipse.jetty.server.Handler createHandler(AppVersion appVersion)
throws ServletException {
// Need to set thread context classloader for the duration of the scope.
ClassLoader oldContextClassLoader = Thread.currentThread().getContextClassLoader();
Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
try {
return doCreateHandler(appVersion);
} finally {
Thread.currentThread().setContextClassLoader(oldContextClassLoader);
}
}
private org.eclipse.jetty.server.Handler doCreateHandler(AppVersion appVersion)
throws ServletException {
try {
File contextRoot = appVersion.getRootDirectory();
final AppEngineWebAppContext context =
new AppEngineWebAppContext(appVersion.getRootDirectory(), serverInfo);
context.getCoreContextHandler().setServer(server);
context.setServer(server);
context.setDefaultsDescriptor(WEB_DEFAULTS_XML);
ClassLoader classLoader = appVersion.getClassLoader();
context.setClassLoader(classLoader);
if (useJettyErrorPageHandler) {
context.getErrorHandler().setShowStacks(false);
} else {
context.setErrorHandler(new NullErrorHandler());
}
// TODO: because of the shading we do not have a correct
// org.eclipse.jetty.ee8.webapp.Configuration file from
// the runtime-impl jar. It failed to merge content from various modules and only contains
// quickstart.
// Because of this the default configurations are not able to be found by WebAppContext with
// ServiceLoader.
context.setConfigurationClasses(
new String[] {
WebInfConfiguration.class.getCanonicalName(),
WebXmlConfiguration.class.getCanonicalName(),
MetaInfConfiguration.class.getCanonicalName(),
FragmentConfiguration.class.getCanonicalName()
});
/*
* Remove JettyWebXmlConfiguration which allows users to use jetty-web.xml files.
* We definitely do not want to allow these files, as they allow for arbitrary method invocation.
*/
// TODO: uncomment when shaded org.eclipse.jetty.ee8.webapp.Configuration is fixed.
// context.removeConfiguration(new JettyWebXmlConfiguration());
if (Boolean.getBoolean(USE_ANNOTATION_SCANNING)) {
context.addConfiguration(new AnnotationConfiguration());
} else {
context.removeConfiguration(new AnnotationConfiguration());
}
File quickstartXml = new File(contextRoot, "WEB-INF/quickstart-web.xml");
if (quickstartXml.exists()) {
context.addConfiguration(new QuickStartConfiguration());
} else {
context.removeConfiguration(new QuickStartConfiguration());
}
// TODO: review which configurations are added by default.
// prevent jetty from trying to delete the temp dir
context.setPersistTempDirectory(true);
// ensure jetty does not unpack, probably not necessary because the unpacking
// is done by AppEngineWebAppContext
context.setExtractWAR(false);
// ensure exception is thrown if context startup fails
context.setThrowUnavailableOnStartupException(true);
// for JSP 2.2
try {
// Use the App Class loader to try to initialize the JSP machinery.
// Not an issue if it fails: it means the app does not contain the JSP jars in WEB-INF/lib.
Class klass = classLoader.loadClass(TOMCAT_SIMPLE_INSTANCE_MANAGER);
Object sim = klass.getConstructor().newInstance();
context.getServletContext().setAttribute(TOMCAT_INSTANCE_MANAGER, sim);
// Set JSP factory equivalent for:
// JspFactory jspf = new JspFactoryImpl();
klass = classLoader.loadClass(TOMCAT_JSP_FACTORY);
JspFactory jspf = (JspFactory) klass.getConstructor().newInstance();
JspFactory.setDefaultFactory(jspf);
Class.forName("org.apache.jasper.compiler.JspRuntimeContext", true, classLoader);
} catch (Throwable t) {
// No big deal, there are no JSPs in the App since the jsp libraries are not inside the
// web app classloader.
}
SessionsConfig sessionsConfig = appVersion.getSessionsConfig();
SessionManagerHandler.Config.Builder builder = SessionManagerHandler.Config.builder();
if (sessionsConfig.getAsyncPersistenceQueueName() != null) {
builder.setAsyncPersistenceQueueName(sessionsConfig.getAsyncPersistenceQueueName());
}
builder
.setEnableSession(sessionsConfig.isEnabled())
.setAsyncPersistence(sessionsConfig.isAsyncPersistence())
.setServletContextHandler(context);
SessionManagerHandler.create(builder.build());
// Pass the AppVersion on to any of our servlets (e.g. ResourceFileServlet).
context.setAttribute(AppEngineConstants.APP_VERSION_CONTEXT_ATTR, appVersion);
if (Boolean.getBoolean(HTTP_CONNECTOR_MODE)) {
context.addEventListener(
new ContextHandler.ContextScopeListener() {
@Override
public void enterScope(
ContextHandler.APIContext context,
org.eclipse.jetty.ee8.nested.Request request,
Object reason) {
if (request != null) {
ApiProxy.Environment environment =
(ApiProxy.Environment)
request.getAttribute(AppEngineConstants.ENVIRONMENT_ATTR);
if (environment != null) {
ApiProxy.setEnvironmentForCurrentThread(environment);
}
}
}
@Override
public void exitScope(
ContextHandler.APIContext context, org.eclipse.jetty.ee8.nested.Request request) {
ApiProxy.clearEnvironmentForCurrentThread();
}
});
}
return context.get();
} catch (Exception ex) {
throw new ServletException(ex);
}
}
/**
* {@code NullErrorHandler} does nothing when an error occurs. The exception is already stored in
* an attribute of {@code request}, but we don't do any rendering of it into the response, UNLESS
* the webapp has a designated error page (servlet, jsp, or static html) for the current error
* condition (exception type or error code).
*/
private static class NullErrorHandler extends ErrorPageErrorHandler {
@Override
public void handle(
String target,
org.eclipse.jetty.ee8.nested.Request baseRequest,
HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
logger.atFine().log("Custom Jetty ErrorHandler received an error notification.");
mayHandleByErrorPage(request, response);
// We don't want Jetty to do anything further.
baseRequest.setHandled(true);
}
/**
* Try to invoke a custom error page if a handler is available. If not, render a simple HTML
* response for {@link HttpServletResponse#sendError} calls, but do nothing for unhandled
* exceptions.
*
* This is loosely based on {@link ErrorPageErrorHandler#handle} but has been modified to add
* a fallback simple HTML response (because Jetty's default response is not satisfactory) and to
* set a special {@code ERROR_PAGE_HANDLED} attribute that disables our default behavior of
* returning the exception to the appserver for rendering.
*/
private void mayHandleByErrorPage(HttpServletRequest request, HttpServletResponse response)
throws IOException {
// Extract some error handling info from Jetty's proprietary attributes.
Throwable error = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
Integer code = (Integer) request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
String message = (String) request.getAttribute(RequestDispatcher.ERROR_MESSAGE);
// Now try to find an error handler...
String errorPage = getErrorPage(request);
// If we found an error handler, dispatch to it.
if (errorPage != null) {
// Check for reentry into the same error page.
String oldErrorPage = (String) request.getAttribute(WebAppContext.ERROR_PAGE);
if (oldErrorPage == null || !oldErrorPage.equals(errorPage)) {
request.setAttribute(WebAppContext.ERROR_PAGE, errorPage);
Dispatcher dispatcher = (Dispatcher) _servletContext.getRequestDispatcher(errorPage);
try {
if (dispatcher != null) {
dispatcher.error(request, response);
// Set this special attribute iff the dispatch actually works!
// We use this attribute to decide if we want to keep the response content
// or let the Runtime generate the default error page
// TODO: an invalid html dispatch (404) will mask the exception
request.setAttribute(ERROR_PAGE_HANDLED, errorPage);
return;
} else {
logger.atWarning().log("No error page %s", errorPage);
}
} catch (ServletException e) {
logger.atWarning().withCause(e).log("Failed to handle error page.");
}
}
}
// If we got an error code (e.g. this is a call to HttpServletResponse#sendError),
// then render our own HTML. XFE has logic to do this, but the PFE only invokes it
// for error conditions that it or the AppServer detect.
if (code != null && message != null) {
// This template is based on the default XFE error response.
response.setContentType("text/html; charset=UTF-8");
String messageEscaped = HtmlEscapers.htmlEscaper().escape(message);
PrintWriter writer = response.getWriter();
writer.println("
");
writer.println("");
writer.println("" + code + " " + messageEscaped + " ");
writer.println("");
writer.println("");
writer.println("Error: " + messageEscaped + "
");
writer.println("");
return;
}
// If we got this far and *did* have an exception, it will be
// retrieved and thrown at the end of JettyServletEngineAdapter#serviceRequest.
throw new IllegalStateException(error);
}
}
}