Github user uce commented on a diff in the pull request:
https://github.com/apache/flink/pull/3460#discussion_r104407909
--- Diff:
flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/files/AbstractStaticFileServerHandler.java
---
@@ -0,0 +1,350 @@
+/*
+ * 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.flink.runtime.webmonitor.files;
+
+/*****************************************************************************
+ * This code is based on the "HttpStaticFileServerHandler" from the
+ * Netty project's HTTP server example.
+ *
+ * See http://netty.io and
+ *
https://github.com/netty/netty/blob/4.0/example/src/main/java/io/netty/example/http/file/HttpStaticFileServerHandler.java
+
*****************************************************************************/
+
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.DefaultFileRegion;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.DefaultHttpResponse;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpChunkedInput;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.LastHttpContent;
+import io.netty.handler.codec.http.router.Routed;
+import io.netty.handler.ssl.SslHandler;
+import io.netty.handler.stream.ChunkedFile;
+import io.netty.util.CharsetUtil;
+import org.apache.flink.util.Preconditions;
+import org.slf4j.Logger;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.RandomAccessFile;
+import java.net.URI;
+import java.net.URL;
+import java.nio.file.Files;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.Locale;
+import java.util.TimeZone;
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.CACHE_CONTROL;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
+import static io.netty.handler.codec.http.HttpHeaders.Names.DATE;
+import static io.netty.handler.codec.http.HttpHeaders.Names.EXPIRES;
+import static
io.netty.handler.codec.http.HttpHeaders.Names.IF_MODIFIED_SINCE;
+import static io.netty.handler.codec.http.HttpHeaders.Names.LAST_MODIFIED;
+import static
io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
+import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
+import static io.netty.handler.codec.http.HttpResponseStatus.NOT_MODIFIED;
+import static io.netty.handler.codec.http.HttpResponseStatus.OK;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+/**
+ * Simple file server handler that serves requests to web frontend's
static files, such as
+ * HTML, CSS, or JS files.
+ *
+ * <p>This code is based on the "HttpStaticFileServerHandler" from the
Netty project's HTTP server
+ * example.</p>
+ */
+public abstract class AbstractStaticFileServerHandler extends
SimpleChannelInboundHandler<Routed> {
+
+ /** Timezone in which this server answers its "if-modified" requests */
+ private static final TimeZone GMT_TIMEZONE =
TimeZone.getTimeZone("GMT");
+
+ /** Date format for HTTP */
+ public static final String HTTP_DATE_FORMAT = "EEE, dd MMM yyyy
HH:mm:ss zzz";
+
+ /** Be default, we allow files to be cached for 5 minutes */
+ private static final int HTTP_CACHE_SECONDS = 300;
+
+ /** The log for all error reporting */
+ protected final Logger logger;
+
+ /** The path in which the static documents are */
+ private final File rootPath;
+
+ public AbstractStaticFileServerHandler(Logger logger, File rootPath)
throws IOException {
+ this.logger = Preconditions.checkNotNull(logger);
+ this.rootPath =
Preconditions.checkNotNull(rootPath).getCanonicalFile();
+ }
+
+ @Override
+ public void channelRead0(ChannelHandlerContext ctx, Routed routed)
throws Exception {
+ String requestPath = routed.path();
+
+ // make sure we request the "index.html" in case there is a
directory request
+ if (requestPath.endsWith("/")) {
+ requestPath = requestPath + "index.html";
+ }
+
+ requestPath = preProcessRequestPath(requestPath);
+
+ handleRequest(ctx, routed, requestPath);
+ }
+
+ protected void handleRequest(ChannelHandlerContext ctx, Routed routed,
String requestPath) throws Exception {
+ respond(ctx, routed.request(), requestPath);
+ }
+
+ protected void respond(ChannelHandlerContext ctx, HttpRequest request,
String requestPath) throws IOException, ParseException {
+ // convert to absolute path
+ final File file = new File(rootPath, requestPath);
+
+ if (!file.exists()) {
+ // file does not exist. Try to load it with the
classloader
+ ClassLoader cl =
StaticFileServerHandler.class.getClassLoader();
+
+ requestPath = preProcessFilePath(requestPath);
+
+ try(InputStream resourceStream =
cl.getResourceAsStream("web" + requestPath)) {
+ boolean success = false;
+ try {
+ if (resourceStream != null) {
+ URL root =
cl.getResource("web");
+ URL requested =
cl.getResource("web" + requestPath);
+
+ if (root != null && requested
!= null) {
+ URI rootURI = new
URI(root.getPath()).normalize();
+ URI requestedURI = new
URI(requested.getPath()).normalize();
+
+ // Check that we don't
load anything from outside of the
+ // expected scope.
+ if
(!rootURI.relativize(requestedURI).equals(requestedURI)) {
+
logger.debug("Loading missing file from classloader: {}", requestPath);
+ // ensure that
directory to file exists.
+
file.getParentFile().mkdirs();
+
Files.copy(resourceStream, file.toPath());
+
+ success = true;
+ }
+ }
+ }
+ } catch (Throwable t) {
+ logger.error("error while responding",
t);
+ } finally {
+ if (!success) {
+ logger.debug("Unable to load
requested file {} from classloader", requestPath);
+
handleUnavailableFile(requestPath);
+ sendError(ctx, NOT_FOUND);
+ return;
+ }
+ }
+ }
+ }
+
+ if (!file.exists() || file.isHidden() || file.isDirectory() ||
!file.isFile()) {
+ sendError(ctx, NOT_FOUND);
+ return;
+ }
+
+ if
(!file.getCanonicalFile().toPath().startsWith(rootPath.toPath())) {
+ sendError(ctx, NOT_FOUND);
+ return;
+ }
+
+ // cache validation
+ final String ifModifiedSince =
request.headers().get(IF_MODIFIED_SINCE);
+ if (ifModifiedSince != null && !ifModifiedSince.isEmpty()) {
+ SimpleDateFormat dateFormatter = new
SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US);
+ Date ifModifiedSinceDate =
dateFormatter.parse(ifModifiedSince);
+
+ // Only compare up to the second because the datetime
format we send to the client
+ // does not have milliseconds
+ long ifModifiedSinceDateSeconds =
ifModifiedSinceDate.getTime() / 1000;
+ long fileLastModifiedSeconds = file.lastModified() /
1000;
+ if (ifModifiedSinceDateSeconds ==
fileLastModifiedSeconds) {
+ if (logger.isDebugEnabled()) {
+ logger.debug("Responding 'NOT MODIFIED'
for file '" + file.getAbsolutePath() + '\'');
+ }
+
+ sendNotModified(ctx);
+ return;
+ }
+ }
+
+ if (logger.isDebugEnabled()) {
+ logger.debug("Responding with file '" +
file.getAbsolutePath() + '\'');
+ }
+
+ // Don't need to close this manually. Netty's DefaultFileRegion
will take care of it.
+ final RandomAccessFile raf;
+ try {
+ raf = new RandomAccessFile(file, "r");
+ }
+ catch (FileNotFoundException e) {
+ sendError(ctx, NOT_FOUND);
+ return;
+ }
+ long fileLength = raf.length();
+
+ HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
+ setContentTypeHeader(response, file);
+
+ // since the log and out files are rapidly changing, we don't
want to browser to cache them
+ if (shouldCache(requestPath)) {
+ setDateAndCacheHeaders(response, file);
+ }
+ if (HttpHeaders.isKeepAlive(request)) {
+ response.headers().set(CONNECTION,
HttpHeaders.Values.KEEP_ALIVE);
+ }
+ HttpHeaders.setContentLength(response, fileLength);
+
+ // write the initial line and the header.
+ ctx.write(response);
+
+ // write the content.
+ ChannelFuture lastContentFuture;
+ if (ctx.pipeline().get(SslHandler.class) == null) {
+ ctx.write(new DefaultFileRegion(raf.getChannel(), 0,
fileLength), ctx.newProgressivePromise());
+ lastContentFuture =
ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
+ } else {
+ lastContentFuture = ctx.writeAndFlush(new
HttpChunkedInput(new ChunkedFile(raf, 0, fileLength, 8192)),
+ ctx.newProgressivePromise());
+ // HttpChunkedInput will write the end marker
(LastHttpContent) for us.
+ }
+
+ // close the connection, if no keep-alive is needed
+ if (!HttpHeaders.isKeepAlive(request)) {
+
lastContentFuture.addListener(ChannelFutureListener.CLOSE);
+ }
+ }
+
+ protected abstract String preProcessRequestPath(String requestPath);
+
+ protected abstract boolean shouldCache(String requestPath);
+
+ protected String preProcessFilePath(String requestPath) {
+ return requestPath;
+ }
+
+ protected void handleUnavailableFile(String requestPath) {
+ }
+
+ @Override
+ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
{
+ if (ctx.channel().isActive()) {
+ logger.error("Caught exception", cause);
+ sendError(ctx, INTERNAL_SERVER_ERROR);
+ }
+ }
+
+ //
------------------------------------------------------------------------
+ // Utilities to encode headers and responses
+ //
------------------------------------------------------------------------
+
+ public static Date convertTimestampToDate(String timestamp) throws
ParseException {
--- End diff --
Unused method
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