rgw: check zone_id or zone_name not empty for zone get sub-command

[david-z]

Fixes: http://tracker.ceph.com/issues/24846

Signed-off-by: Zhi Zhang zhangz.david@outlook.com

[david-z]

@oritwas Pls help to review this PR, thanks.

[tianshan]

if zone_id & zone_name are both empty, will get the default zone, so I think it's not necessary.

[david-z]

@tianshan Pls check the tracker, you can see if run radosgw-admin zone get, it will return default zone info, but this doesn't make sense because no zone id or zone name is even specified. And if run radosgw-admin zone get XXX, it will return the default zone info. If we don't check both options and return error msg, it will bring much trouble to tell whether this zone info is correct for XXX, especially for cluster operator.

And all the other radosgw-admin zone sub-commands checked both options, I think zone get should do the same.

[tianshan]

@david-z I think it's another issue about zone get XXX that didn't parse the extra param.
I'm agree that make the cmd more certain is good point, meanwhile it's fine return default zone info for me if no zone id or name provided.

[cbodley]

agree with @tianshan, this would be a regression that breaks 'radosgw-admin zone get' to read the default zone

[david-z]

@cbodley @tianshan OK, I understand. If this breaks regression test, can we at least output an warning msg to indicate the default zone is returned? Will the warning msg break the regression test?

Thanks.

[david-z]

@cbodley @tianshan

Hi Guys,

Could you pls take a look at my last comment? Or shall we continue following this issue any way?

[cbodley]

hi @david-z, my concern is not that a warning will break tests. it's more that the 'default zone' is itself a feature - it's controlled with the zone default command and --default option to zone create/modify, and means that zone is used by default when no --rgw-zone is provided - this applies globally to all radosgw/radosgw-admin commands.

it just doesn't seem right to warn people that make use of this feature. i would rather find a way to improve our documentation to eliminate this kind of confusion

[david-z]

Thanks for the explanation. I will close this PR.