org.apache.reef.runtime.yarn.client.UserCredentialSecurityTokenProvider.java Source code

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Here is the source code for org.apache.reef.runtime.yarn.client.UserCredentialSecurityTokenProvider.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 org.apache.reef.runtime.yarn.client;

import org.apache.hadoop.io.DataOutputBuffer;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;

import javax.inject.Inject;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Reads security token from user credentials.
 */
final class UserCredentialSecurityTokenProvider implements SecurityTokenProvider {

    private static final Logger LOG = Logger.getLogger(UserCredentialSecurityTokenProvider.class.getName());

    @Inject
    private UserCredentialSecurityTokenProvider() {
    }

    @Override
    public byte[] getTokens() {
        try {
            final UserGroupInformation ugi = UserGroupInformation.getCurrentUser();
            final Credentials credentials = ugi.getCredentials();
            if (credentials.numberOfTokens() > 0) {
                try (final DataOutputBuffer dob = new DataOutputBuffer()) {
                    credentials.writeTokenStorageToStream(dob);
                    return dob.getData();
                }
            }
        } catch (IOException e) {
            LOG.log(Level.WARNING, "Could not access tokens in user credentials.", e);
        }

        LOG.log(Level.FINE, "No security token found.");
        return null;
    }
}