Cannot change configuration when using cloud_storage_credentials_source!=config_file

[nicolaferraro]

Version & Environment

Redpanda version: latest

What went wrong?

I started a cluster with cloud_storage_credentials_source=sts and no value for cloud_storage_access_key or cloud_storage_secret_key (they are not needed when using sts or anything different from config_file).

Trying to change another config, like cluster_id (rpk cluster config set cluster_id xxx), I get a validation error saying that both cloud_storage_access_key and cloud_storage_secret_key are required.

What should have happened instead?

When using cloud_storage_credentials_source!=config_file then cloud_storage_access_key and cloud_storage_secret_key should not be required in config validaiton

cc: @jcsp

[jcsp]

I think this wasn't caught in tests because they set the property in extra_rp_conf before starting redpanda, and then the property is getting loaded via the bootstrap config rather than via the validated admin_server.cc path.

The validation needs fixing in admin_server.cc config_multi_property_validation