Add support for whitelist configuration about minectl HOT 4 OPEN

My summary:

1. Minectl creates the actual JSON-files, no use of RCON (so the user is not required to configure RCON to use this)
2. Minectl allows to put in the uuid in the configuration, but looks up the uuid throughhttps://github.com/Electroid/mojang-api if it's not given
3. If there is an unkown username, Minectl posts a warning, but doesn't cancel scaffolding
4. by default, minectl overwrites the existing whitelist. An additional option (--merge-configs) allows for just adding user not already in the whitelist
5. the whitelist will be applied to minecraft servers, not to any proxy (did a little research and it appeared that this is how it's done)
6. the same principles will be applied to the op list (would however create a second issue to keep them seperate as they provide 2 different capabilities just based on the same principles)

If that's fine by you I'd start working on the feature.

from minectl.

@dirien Input is highly welcome.

For the first point I'd prefer option c) with the possibility for optoin a):

• if the user provides both uuid and name the CLI takes the provided information
• if the user only provides the name the CLI looks up the corresponding uuids

The second point however has a lot of potential for conflict or confusion.

from minectl.

I like this feature, you can extend this also tho op list. Atm, i need to RCON to the server to add a user to the ops list.

Regarding the the three options have a look into my prometheus exporter -> https://github.com/dirien/minecraft-prometheus-exporter#api. There i use tha API from https://github.com/Electroid/mojang-api. Its much better then the vanilla mojang api.

As in the nature of minectl you need to have online conection, we could use the Electroid API to get the UUID/ID from there and treat the target server as potential offline. eg. server in a BungeCord mesh has to set the propery online-mode to false.

2. I see minctl as a ignition tool, bootstrapping a minecraft server and having some convinience fn by hand. Later we want to build a Crossplane / K8s Operator. and with the k8s conciliation pattern, we can use minectl-operator also to prevent configuration drift on managed resources. For now, i would calc the hash and warn the user (or a flag --force) that the server file will be overwritten. What you think?

from minectl.

@iglrob, LGTM! Looking forward for your PR.

from minectl.