org.apache.hadoop.yarn.server.webproxy.ProxyUtils Maven / Gradle / Ivy
/*
* 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.hadoop.yarn.server.webproxy;
import org.apache.hadoop.yarn.webapp.MimeType;
import org.apache.hadoop.yarn.webapp.hamlet2.Hamlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.EnumSet;
/**
* Class containing general purpose proxy utilities
*/
public class ProxyUtils {
private static final Logger LOG = LoggerFactory.getLogger(
ProxyUtils.class);
public static final String E_HTTP_HTTPS_ONLY =
"This filter only works for HTTP/HTTPS";
public static final String LOCATION = "Location";
public static class __ implements Hamlet.__ {
//Empty
}
public static class Page extends Hamlet {
Page(PrintWriter out) {
super(out, 0, false);
}
public HTML html() {
return new HTML<>("html", null, EnumSet.of(EOpt.ENDTAG));
}
}
/**
* Handle redirects with a status code that can in future support verbs other
* than GET, thus supporting full REST functionality.
*
* The target URL is included in the redirect text returned
*
* At the end of this method, the output stream is closed.
*
* @param request request (hence: the verb and any other information
* relevant to a redirect)
* @param response the response
* @param target the target URL -unencoded
*
*/
public static void sendRedirect(HttpServletRequest request,
HttpServletResponse response,
String target)
throws IOException {
LOG.debug("Redirecting {} {} to {}",
request.getMethod(),
request.getRequestURI(),
target);
String location = response.encodeRedirectURL(target);
response.setStatus(HttpServletResponse.SC_FOUND);
response.setHeader(LOCATION, location);
response.setContentType(MimeType.HTML);
PrintWriter writer = response.getWriter();
Page p = new Page(writer);
p.html()
.head().title("Moved").__()
.body()
.h1("Moved")
.div()
.__("Content has moved ")
.a(location, "here").__()
.__().__();
writer.close();
}
/**
* Output 404 with appropriate message.
* @param resp the http response.
* @param message the message to include on the page.
* @throws IOException on any error.
*/
public static void notFound(HttpServletResponse resp, String message)
throws IOException {
resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
resp.setContentType(MimeType.HTML);
Page p = new Page(resp.getWriter());
p.html().
h1(message).
__();
}
/**
* Reject any request that isn't from an HTTP servlet
* @param req request
* @throws ServletException if the request is of the wrong type
*/
public static void rejectNonHttpRequests(ServletRequest req) throws
ServletException {
if (!(req instanceof HttpServletRequest)) {
throw new ServletException(E_HTTP_HTTPS_ONLY);
}
}
}