Get the list of namenodes the user may access.
Obtains token for the Hive metastore, using the current user as the principal.
Obtains token for the Hive metastore, using the current user as the principal. Some exceptions are caught and downgraded to a log message.
hadoop configuration; the Hive configuration will be based on this
a token, or None
if there's no need for a token (no metastore URI or principal
in the config), or if a binding exception was caught and downgraded.
Obtains tokens for the namenodes passed in and adds them to the credentials.
Contains util methods to interact with Hadoop from spark.