Make cloud sql proxy init action work on kerberized clusters. (#544)
Make cloud sql proxy init action work on kerberized clusters. (#544)

* Make cloud sql proxy init action work on kerberized clusters.

* Use fqdn for hostname, make realm uppercase

* Use literal string _HOST for host in principal.

* Revert "Use literal string _HOST for host in principal."

This reverts commit d0cc644ddb154955cc84dd2afd6d4e9a8386f681.

GoogleCloudDataproc/initialization-actions,dennishuo/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions,dennishuo/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions