[Secure HDFS] Running List of HDFS Issues

[ifilonenko]

This will act as a running list of issues that need to be resolved for a stable Secure HDFS solution.
@kimoonkim @liyinan926 add more which you feel are appropriate

• Resolution of Yarn configs in K8S world
• Unit test that simulates file system for keytab resolution in Secure HDFS
• Having KerberosBootstrap be passed into the keytab resolution step
• Integration test for HDFS File Mounting
  A PR will be released for this shortly as part of Secure HDFS Support #514
• Integration test for Secure HDFS interaction
  A PR will be released for this shortly as part of Secure HDFS Support #514
• Secure HDFS Renewal Service

If all are checked, we may begin merging with upstream

[kimoonkim]

@ifilonenko Thanks for writing this list. I would add one more item:

• Let the driver and executors discover and pick up new tokens added by the token renew service.