org.apache.hadoop.hdfs.tools.offlineImageViewer.FSImageHandler 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.hdfs.tools.offlineImageViewer;
import com.google.common.base.Charsets;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.QueryStringDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.hdfs.web.JsonUtil;
import org.apache.hadoop.util.StringUtils;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
import static io.netty.handler.codec.http.HttpResponseStatus.METHOD_NOT_ALLOWED;
import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.APPLICATION_JSON_UTF8;
import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.WEBHDFS_PREFIX;
import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.WEBHDFS_PREFIX_LENGTH;
/**
* Implement the read-only WebHDFS API for fsimage.
*/
class FSImageHandler extends SimpleChannelInboundHandler {
public static final Logger LOG =
LoggerFactory.getLogger(FSImageHandler.class);
private final FSImageLoader image;
private final ChannelGroup activeChannels;
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
activeChannels.add(ctx.channel());
}
FSImageHandler(FSImageLoader image, ChannelGroup activeChannels) throws IOException {
this.image = image;
this.activeChannels = activeChannels;
}
@Override
public void channelRead0(ChannelHandlerContext ctx, HttpRequest request)
throws Exception {
if (request.getMethod() != HttpMethod.GET) {
DefaultHttpResponse resp = new DefaultHttpResponse(HTTP_1_1,
METHOD_NOT_ALLOWED);
resp.headers().set(CONNECTION, CLOSE);
ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
return;
}
QueryStringDecoder decoder = new QueryStringDecoder(request.getUri());
// check path. throw exception if path doesn't start with WEBHDFS_PREFIX
String path = getPath(decoder);
final String op = getOp(decoder);
// check null op
if (op == null) {
throw new IllegalArgumentException("Param op must be specified.");
}
final String content;
switch (op) {
case "GETFILESTATUS":
content = image.getFileStatus(path);
break;
case "LISTSTATUS":
content = image.listStatus(path);
break;
case "GETACLSTATUS":
content = image.getAclStatus(path);
break;
case "GETXATTRS":
List names = getXattrNames(decoder);
String encoder = getEncoder(decoder);
content = image.getXAttrs(path, names, encoder);
break;
case "LISTXATTRS":
content = image.listXAttrs(path);
break;
case "GETCONTENTSUMMARY":
content = image.getContentSummary(path);
break;
default:
throw new IllegalArgumentException("Invalid value for webhdfs parameter"
+ " \"op\"");
}
LOG.info("op=" + op + " target=" + path);
DefaultFullHttpResponse resp = new DefaultFullHttpResponse(HTTP_1_1,
HttpResponseStatus.OK, Unpooled.wrappedBuffer(content
.getBytes(Charsets.UTF_8)));
resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
resp.headers().set(CONTENT_LENGTH, resp.content().readableBytes());
resp.headers().set(CONNECTION, CLOSE);
ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
Exception e = cause instanceof Exception ? (Exception) cause : new
Exception(cause);
final String output = JsonUtil.toJsonString(e);
ByteBuf content = Unpooled.wrappedBuffer(output.getBytes(Charsets.UTF_8));
final DefaultFullHttpResponse resp = new DefaultFullHttpResponse(
HTTP_1_1, INTERNAL_SERVER_ERROR, content);
resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
if (e instanceof IllegalArgumentException) {
resp.setStatus(BAD_REQUEST);
} else if (e instanceof FileNotFoundException) {
resp.setStatus(NOT_FOUND);
} else if (e instanceof IOException) {
resp.setStatus(FORBIDDEN);
}
resp.headers().set(CONTENT_LENGTH, resp.content().readableBytes());
resp.headers().set(CONNECTION, CLOSE);
ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
}
private static String getOp(QueryStringDecoder decoder) {
Map> parameters = decoder.parameters();
return parameters.containsKey("op")
? StringUtils.toUpperCase(parameters.get("op").get(0)) : null;
}
private static List getXattrNames(QueryStringDecoder decoder) {
Map> parameters = decoder.parameters();
return parameters.get("xattr.name");
}
private static String getEncoder(QueryStringDecoder decoder) {
Map> parameters = decoder.parameters();
return parameters.containsKey("encoding") ? parameters.get("encoding").get(
0) : null;
}
private static String getPath(QueryStringDecoder decoder)
throws FileNotFoundException {
String path = decoder.path();
if (path.startsWith(WEBHDFS_PREFIX)) {
return path.substring(WEBHDFS_PREFIX_LENGTH);
} else {
throw new FileNotFoundException("Path: " + path + " should " +
"start with " + WEBHDFS_PREFIX);
}
}
}