Please allow configuration of rgw_relaxed_s3_bucket_names option

Thanks for filing this enhancement and for helping to make the charms better. I am triaging this as wishlist.

When implementing this change with config-flags, the implementation of config-flags seems to have failed to create a new section per the config-flags definition:

juju config ceph-radosgw config-flags='{"client.radosgw.gateway": {"rgw_relaxed_s3_bucket_names": "true"}}'

The /etc/ceph/config file has the following three extra lines from this config change:

# The following are user-provided options provided via the config-flags charm option.
# User-provided [client.radosgw.gateway] section config
rgw_relaxed_s3_bucket_names = true

Expected result would be these two lines (plus any juju comments):
[client.radosgw.gateway]
rgw_relaxed_s3_bucket_names = true

Note the lack of DEFINING the [client.radosgw.gateway] section of the file.

root@juju-733f2f-4-lxd-12:/etc/ceph# grep '\[' ceph.conf
[global]
[client.rgw.juju-733f2f-4-lxd-12]
# User-provided [client.radosgw.gateway] section config

It may seem a bit confusing, but where radosgw runs via systemd rather than upstart - the client id is actually rgw.<hostname>. The charm provides a convenience of mapping client.radosgw.gateway (legacy client id) into the new client id mapping transparently. Thus, when specifying client.radosgw.gateway it will be mapped the the client.rgw.<hostname> section itself.

As such, this setting applies properly to the ceph.conf. You can audit this by using the admin socket like so:

# The current values of the rgw service
root@juju-504a16-zaza-fc8300987aa2-7:/etc/ceph# ceph daemon /var/run/ceph/ceph-client.rgw.juju-504a16-zaza-fc8300987aa2-7.376436.93842140922864.asok config get rgw_relaxed_s3_bucket_names
{
    "rgw_relaxed_s3_bucket_names": "true"
}

Where the admin socket name will actually vary, but will be in the /var/run/ceph directory.

Specifically, enabling this setting is not allowing for 2 letter bucket names such as "dr" or "tl".

The rgw_relaxed_s3_bucket_names option does not affect the minimum length of bucket names (3). That option allows you to have a bucket name longer (255 chars) than the default (63 chars).

FWIW, the rgw_relaxed_s3_bucket_names setting allows for:

1. longer bucket names
2. upper case letters in bucket names
3. bucket names starting with _, . or -
4. bucket names containing an _
5. consecutive . or - characters
6. bucket names ending with a non-alphanumeric character

But only in the case that the s3 protocol is used to access the buckets.

Reviewed: https://review.opendev.org/c/openstack/charm-ceph-radosgw/+/841797
Committed: https://opendev.org/openstack/charm-ceph-radosgw/commit/2bda1f68a6aa996cf4f8992bfe8bf7ebaa13a9c0
Submitter: "Zuul (22348)"
Branch: master

commit 2bda1f68a6aa996cf4f8992bfe8bf7ebaa13a9c0
Author: Ethan Myers <email address hidden>
Date: Fri May 13 14:14:29 2022 -0600

    Add a config option for relaxed s3 bucket names.

    Closes-Bug: #1926498
    Change-Id: I4b329f3327a0e91ccd9f65841cc5d62736918a85