title: Error with Kerberos authentication when executing Flink example code on YARN cluster (Cloudera)
body: <p>I was trying Flink on YARN cluster to run the example code (flink<em>examples</em>WordCount.jar) but am getting the below security authentication error. </p>
  
  <pre><code>org.apache.flink.client.program.ProgramInvocationException: The program execution failed: Cannot initialize task 'DataSink (CsvOutputFormat (path: hdfs://10.94.146.126:8020/user/qawsbtch/flink_out, delimiter:  ))': SIMPLE authentication is not enabled.  Available:[TOKEN, KERBEROS]
  </code></pre>
  
  <p>I am not sure where the issue is and what is that I am missing to do. I could run spark or map-reduce jobs without any issue in the same cloudera hadoop cluster.</p>
  
  <p>I did update the CONF file paths for hdfs-site.xml and core-site.xml in the flink-conf.yaml (updated same in Master and Worker nodes) and also export the HADOOP_CONF_DIR path. Also I tried give the host:port in the HDFS file path when executing flink run command.</p>
  
  <p>ERROR MESSAGE</p>
  
  <pre><code>    22:14:25,138 ERROR   org.apache.flink.client.CliFrontend                           - Error while running the command.
  org.apache.flink.client.program.ProgramInvocationException: The program execution failed: Cannot initialize task 'DataSink (CsvOutputFormat (path: hdfs://10.94.146.126:8020/user/qawsbtch/flink_out, delimiter:  ))': SIMPLE authentication is not enabled.  Available:[TOKEN, KERBEROS]
          at org.apache.flink.client.program.Client.run(Client.java:413)
          at org.apache.flink.client.program.Client.run(Client.java:356)
          at org.apache.flink.client.program.Client.run(Client.java:349)
          at org.apache.flink.client.program.ContextEnvironment.execute(ContextEnvironment.java:63)
          at org.apache.flink.examples.java.wordcount.WordCount.main(WordCount.java:78)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:606)
          at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:437)
          at org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:353)
          at org.apache.flink.client.program.Client.run(Client.java:315)
          at org.apache.flink.client.CliFrontend.executeProgram(CliFrontend.java:584)
          at org.apache.flink.client.CliFrontend.run(CliFrontend.java:290)
          at org.apache.flink.client.CliFrontend$2.run(CliFrontend.java:873)
          at org.apache.flink.client.CliFrontend$2.run(CliFrontend.java:870)
          at org.apache.flink.runtime.security.SecurityUtils$1.run(SecurityUtils.java:50)
          at java.security.AccessController.doPrivileged(Native Method)
          at javax.security.auth.Subject.doAs(Subject.java:415)
          at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
          at org.apache.flink.runtime.security.SecurityUtils.runSecured(SecurityUtils.java:47)
          at org.apache.flink.client.CliFrontend.parseParameters(CliFrontend.java:870)
          at org.apache.flink.client.CliFrontend.main(CliFrontend.java:922)
  Caused by: org.apache.flink.runtime.client.JobExecutionException: Cannot initialize task 'DataSink (CsvOutputFormat (path: hdfs://10.94.146.126:8020/user/qawsbtch/flink_out, delimiter:  ))': SIMPLE authentication is not enabled.  Available:[TOKEN, KERBEROS]
  </code></pre>