Glowstone for Erlang

This project is a proof-of-concept port of Tom Heinan's Ruby Glowstone project in Erlang. Here's a redacted version of his original README file.

This module implements the GameSpy query protocol to access pertinent real-time information hidden away inside your Minecraft server. You give Glowstone your server info, and Glowstone gives you:

which players are currently online
the base map name and default gamemode
what plugins you're running
even more stuff you probably don't care about!

All credit goes to Dinnerbone for his excellent post on the inner workings of the protocol. Check out his Python implementation here.

Requirements

You should only need a somewhat recent version of Erlang/OTP. The module has been tested with Erlang R15B and R16B.

You also need a recent version of rebar in the system path.

Installation

Run the following commands to checkout, retrieve the dependencies and compile the project:

git clone https://github.com/jcomellas/glowstone.git
cd glowstone
rebar get-deps compile

Usage

Glowstone's interface is super simple. Just start the application and a client (with the host name and port the server is listening on):

glowstone:start().
{ok, Pid} = glowstone:start_client("minecraft.example.com", 25565, [{timeout, 10000}]).

And Glowstone will whip you up a process full of all that delicious realtime data you've been craving:

glowstone:status(Pid).
[{motd,<<"Welcome to Arkenfall!">>},
 {game_type,<<"SMP">>},
 {game_name,<<"MINECRAFT">>},
 {version,<<"1.6.4">>},
 {plugins,[<<"CraftBukkit on Bukkit 1.6.4-R0.1-SNAPSHOT: AdminCmd 7.3.5 (BUILD 06.04.2013 @ 18:26:"...>>,
           <<"Vault 1.2.25-b320">>,<<"WorldEdit 5.5.7">>,
           <<"TreeAssist 5.4.2">>,<<"WorldGuard 5.7.5">>,
           <<"PlayerMarkers 0.2.0">>,<<"PermissionsBukkit 2.0">>,
           <<"SimpleSpleef 3.4.2">>]},
 {map_name,<<"arkenfall">>},
 {num_players,0},
 {max_players,16},
 {players,[]},
 {last_update,{{2013,10,16},{18,46,4}}}]

And that's all there is to it! No fancy bukkit plugins or server-side scripts required. If your process is particularly long-lived and you find yourself wanting to refresh its data, just do glowstone:refresh(Pid) and it'll pull down the latest information for you.

Troubleshooting

Help! I'm not receiving any data!

The first thing to do is make sure your server is set up to send it. Check your server.properties file and make sure the enable-query flag is set to true. Then, make sure your server's firewall allows connections on UDP port 25565. If you've changed that value via the query.port flag, then you'll also need to specify it when instantiating Glowstone, like so:

{ok, Pid} = glowstone:start_client("myminecraftserver.com", 25565, []).

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Added some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request