Snap! - Run BungeeCord plugins on Velocity

This is the Seriously Necessary Adapter Plugin to enable plugins written against the
BungeeCord or Waterfall API to load and (kinda) run on Velocity. :eyes:

Please note that this is currently in an experimental state, you should not run this in production without excessive testing!

How?

Simply add the Bungee plugins into the plugins folder inside the Snap plugin folder.

Snap will use it’s own instance of BungeeCord’s plugin manager to load the plugins from there and translate BungeeCord methods, classes as well as event calls to the respective Velocity ones and vice versa.

Why?

Originally I wanted to document the Velocity equivalents to Bungee events, methods and classes. This evolved into the idea of writing a converter for source code which led me to decide to try to make a plugin which can directly load Bungee plugins.

Seeing as the proxies don’t have too much logic that seems to have worked although it is definitely a lot more inefficient than just running native Velocity plugins due lots of classes being in need of getting translated on the fly.

Technically this could be made in a way that is a lot more efficient by directly modifying the Velocity or BungeeCord source code to extend the respective other classes but in practice that massively increases the work required to get this plugin running, and that’s all I wanted to do for now.

What works?

Most of it (hopefully). I mean that’s the goal… make sure to report any issues!

What doesn’t work?

Some functionality isn’t easily recreated (e.g. group handling is not a thing in Velocity, use a permissions plugin) and of course anything related to hacking into Bungee-internals or packets wont work. Just write a Velocity plugin at that point…

Those functions not supported will throw an UnsupportedOperationException. Please report those including the plugin causing them on the issue tracker!

If you are sure that the plugin will work fine otherwise then you can have it return default values by setting throw-unsupported-exception to false in the snap.conf!

Not supported:

  • Using Bungee’s inbuilt permissions system to set and get groups/permissions.
    Don’t. Use LuckPerms on Velocity. (hasPermission checks work though)
  • Reconnect server functionality. That’s an inbuilt function in Bungee but better suited for a plugin. The related methods will return null or set nothing. Instead of erroring.
  • Scoreboards. Velocity doesn’t have API for them and I’m not going to create a packet based one. Maybe there will be a way to integrate in some plugin or Velocity adds support in the future.
  • Some ProxyConfig settings don’t exist on Velocity or aren’t exposed in the API so they return some sensible defaults which should reflect the proxy’s state.
  • Registering commands after a plugin was enabled. I currently have no good way to hook into this besides straight up modifying the PluginManager class which I would like to avoid.
  • Velocity plugins and Bungee plugins are not available to each other via the respective PluginManager APIs and as dependencies. Their classes should be accessible though.
  • Some connection handling and related events might not work 100% exactly like on Bungee. They are as close as possible though but if you already have to fiddle with that then its best to create a standalone Velocity plugin tbh.
  • Some events don’t work 100% or not at all.
    Not working: TabCompleteEvent, ProxyDefineCommandEvent, ProxyExceptionEvent.
    Only partially: ServerDisconnectEvent (only triggers on kicks),
    ClientConnectEvent (uses Velocity’s LoginEvent with PostOrder.FIRST)
    ConnectionInitEvent (uses Velocity’s LoginEvent with PostOrder.EARLY)
  • Unsafe doesn’t work.

Sounds awesome! How can I get it?

You can download the jar via GitHub releases or get builds from the latest commits from the Minebench.de Jenkins.

How can I support the project?

For the start trying out the plugin and reporting what other plugins work and don’t work would already help a ton figuring out what work is still needed.

Of course I would also appreciate monetary help if the plugin has helped you transition to Velocity either by directly using it or referencing its code to adapt Bungee plugins to get running on Velocity natively. (Did you know that GitHub is still doubling donations to my GitHub Sponsors page? :wink:)

Is it open source?

Yes, the base code of Snap is open source! Unless noted otherwise in the source it’s licensed under LGPLv3 in order to be compatible with the shipped Waterfall/BungeeCord.

 Snap
 Copyright (c) 2020 Max Lee aka Phoenix616 ([email protected])

 This program is free software: you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation, either
 version 3 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this program.  If not, see <http://www.gnu.org/licenses/>.

Please note that BungeeCord is licensed under their own, BSD 3-Clause based license and that Waterfall uses an MIT License for its patches.

Therefore pre-built binaries of Snap would have to be distributed under Bungee’s modified BSD 3-Clause license or a compatible one.

1 Like

does this work for Player Servers?
the plugins uses the YamlConfiguration file to work.

BungeeCord.jar\net\md_5\bungee\config\YamlConfiguration.class

Configurations worked fine in my test (at least in a basic setup), the description lists all known incompatibilities at the moment. If you run into issues while testing please open a ticket on github! :slight_smile:

It makes bug with skin plugins, i tried skinrestorer and customskinmanager both are not changing skin immediately gotta log out and login after that new skin loads. Can you fix this, i also appreciate your work thx

Please open an issue on GitHub for each plugin which doesn’t work with error logs/steps on how to reproduce it.

Skinrestorer have an official port for velocity, you can find it in plugins section

problem is when i use snap, skinrestorer(velocity) dont work well u can try it :slight_smile: