[ZEPPELIN-6075] Configuration for global Roles

[Reamer]

What is this PR for?

This PR adds global roles, which can be stored in the Zeppelin configuration.

What type of PR is it?

Feature

Todos

• - Documentation

What is the Jira issue?

• https://issues.apache.org/jira/browse/ZEPPELIN-6075

How should this be tested?

• Ci

Questions:

• Does the license files need to update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? Yes

[seung-00]

Our team needed this feature too. thank you for contributing. I've left a few simple comments for your review.

[seung-00]

How about using a collection like EnumSet instead of a switch statement to manage valid roles? IMO, this simplifies the code and makes it easier to add or modify roles in the future.

private static final Set<ZeppelinConfiguration.ConfVars> VALID_CONF_VARS = EnumSet.of(
      ZeppelinConfiguration.ConfVars.ZEPPELIN_OWNER_ROLES,
      ZeppelinConfiguration.ConfVars.ZEPPELIN_WRITER_ROLES,
      ZeppelinConfiguration.ConfVars.ZEPPELIN_READER_ROLES,
      ZeppelinConfiguration.ConfVars.ZEPPELIN_RUNNER_ROLES
  );

private Set<String> getDefaultRoles(ZeppelinConfiguration.ConfVars confvar) {
    if (!VALID_CONF_VARS.contains(confvar)) {
      LOGGER.warn("getDefaultRoles is used with {}, which is not valid", confvar);
      return Collections.emptySet();
    }
    ...
}

[Reamer]

Thank you for your review. I have adapted the code and agree with your statements.

[seung-00]

LGTM 👍

[Reamer]

I am using the feature in my company and have come across a bug that should be fixed with the latest commit.
The error should no longer occur because it has been covered by unit tests.
I will roll out the feature in my production environment in the next few days and report back on the status.

[Reamer]

The users of my company report that the error found has now been fixed.