* 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.

*/

* Hbase Credentials implementation to store in jobConf

* The jobConf is used further to pass credentials to the tasks while running

* Oozie server should be configured to use this Credentials class by including it via property 'oozie.credentials.credentialclasses'

*

*/

    /* (non-Javadoc)

     * @see org.apache.oozie.action.hadoop.Credentials#addtoJobConf(org.apache.hadoop.mapred.JobConf, org.apache.oozie.action.hadoop.CredentialsProperties, org.apache.oozie.action.ActionExecutor.Context)

     */

    @Override

    public void addtoJobConf(JobConf jobConf, CredentialsProperties props, Context context) throws Exception {

        try {

            copyHbaseConfToJobConf(jobConf, props);

            obtainToken(jobConf, context);

        }

        catch (Exception e) {

            XLog.getLog(getClass()).warn("Exception in receiving hbase credentials", e);

            throw e;

        }

    }

    void copyHbaseConfToJobConf(JobConf jobConf, CredentialsProperties props) {

        // Create configuration using hbase-site.xml/hbase-default.xml

        Configuration hbaseConf = HBaseConfiguration.create();

        // copy cred props to hbaseconf and override if values already exists

        addPropsConf(props, hbaseConf);

        // copy cred props to jobconf and override if values already exist

        addPropsConf(props, jobConf);

        // copy conf from hbaseConf to jobConf without overriding the

        // already existing values of jobConf

        injectConf(hbaseConf, jobConf);

    }

    private void obtainToken(JobConf jobConf, Context context) throws IOException, InterruptedException {

        String user = context.getWorkflow().getUser();

        UserGroupInformation ugi =  UserGroupInformation.createProxyUser(user, UserGroupInformation.getLoginUser());

        User u = User.create(ugi);

        u.obtainAuthTokenForJob(jobConf);

    }

    private void addPropsConf(CredentialsProperties props, Configuration destConf) {

        for (Map.Entry<String, String> entry : props.getProperties().entrySet()) {

            destConf.set(entry.getKey(), entry.getValue());

        }

    }

    private void injectConf(Configuration srcConf, Configuration destConf) {

        for (Map.Entry<String, String> entry : srcConf) {

            String name = entry.getKey();

            if (destConf.get(name) == null) {

                String value = entry.getValue();

                destConf.set(name, value);

            }

        }

    }

}