joshelser.Client.java Source code

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Here is the source code for joshelser.Client.java

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/*
 * 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 joshelser;

import java.util.HashMap;
import java.util.Map;

import javax.security.sasl.Sasl;

import joshelser.thrift.HdfsService;

import org.apache.hadoop.security.UserGroupInformation;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.transport.TSaslClientTransport;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.beust.jcommander.Parameter;

/**
 * Client configured to pass its UserGroupInformation/Kerberos credentials across a Thrift RPC
 */
public class Client implements ServiceBase {
    private static final Logger log = LoggerFactory.getLogger(Client.class);

    private static class Opts extends ParseBase {
        @Parameter(names = { "-s", "--server" }, required = true, description = "Hostname of Thrift server")
        private String server;

        @Parameter(names = { "--port" }, required = false, description = "Port of the Thrift server, defaults to ")
        private int port = DEFAULT_THRIFT_SERVER_PORT;

        @Parameter(names = { "-p",
                "--primary" }, required = true, description = "Leading component of the Kerberos principal for the server")
        private String primary;

        @Parameter(names = { "-i",
                "--instance" }, required = true, description = "Second component of the Kerberos principal for the server")
        private String instance;

        @Parameter(names = { "-d", "--dir" }, required = false, description = "HDFS directory to perform `ls` on")
        private String dir = "/";
    }

    public static void main(String[] args) throws Exception {
        Opts opts = new Opts();

        // Parse the options
        opts.parseArgs(Client.class, args);

        // Open up a socket to the server:port
        TTransport transport = new TSocket(opts.server, opts.port);
        Map<String, String> saslProperties = new HashMap<String, String>();
        // Use authorization and confidentiality
        saslProperties.put(Sasl.QOP, "auth-conf");

        log.info("Security is enabled: {}", UserGroupInformation.isSecurityEnabled());

        // Log in via UGI, ensures we have logged in with our KRB credentials
        UserGroupInformation currentUser = UserGroupInformation.getCurrentUser();
        log.info("Current user: {}", currentUser);

        // SASL client transport -- does the Kerberos lifting for us
        TSaslClientTransport saslTransport = new TSaslClientTransport("GSSAPI", // tell SASL to use GSSAPI, which supports Kerberos
                null, // authorizationid - null
                opts.primary, // kerberos primary for server - "myprincipal" in myprincipal/my.server.com@MY.REALM
                opts.instance, // kerberos instance for server - "my.server.com" in myprincipal/my.server.com@MY.REALM
                saslProperties, // Properties set, above
                null, // callback handler - null
                transport); // underlying transport

        // Make sure the transport is opened as the user we logged in as
        TUGIAssumingTransport ugiTransport = new TUGIAssumingTransport(saslTransport, currentUser);

        // Setup our thrift client to our custom thrift service
        HdfsService.Client client = new HdfsService.Client(new TBinaryProtocol(ugiTransport));

        // Open the transport
        ugiTransport.open();

        // Invoke the RPC
        String response = client.ls(opts.dir);

        // Print out the result
        System.out.println("$ ls " + opts.dir + "\n" + response);

        // Close the transport (don't leak resources)
        transport.close();
    }
}