hello. i want to configure a nixos machine as a ceph client.
i have this in my config:
```
services.ceph = {      
  global = {      
    fsid = "<uuid>";      
    monHost = "<mon1 ip>, <mon2 ip>, <mon3 ip>";      
  };      
  client = {      
    enable = true;      
    extraConfig = {      
      "client.fs" = { "key" = "<client key>"; };      
    };      
  };      
};      
```
but neither does it generate a ceph.conf nor does it build the "nixos.ceph-client" derivation