Major Description
As part of LENS-1509, we have added Spnego authentication based on Kerberos to lens. This will work in client-server mode. But this approach will cease to work in a hadoop cluster in which user is using lens client in a mapred job(such as oozie java action) since there will not be keytabs in the hadoop cluster. The authentication in hadoop work on concept of delegation token(https://blog.cloudera.com/blog/2017/12/hadoop-delegation-tokens-explained/).
Here we are introducing delegation token auth in lens. We are piggybacking on HDFS to do authentication by passing it's token and performing a filesystem operation.
We will add proper delegation token implementation as future improvement.