Poll the server to get how many players are online

app/cogs/palworld.py

@@ -4,11 +4,13 @@ import discord
 import requests
 from bs4 import BeautifulSoup
 import re
+import os
 
 
 class PalWorld(commands.Cog):
     def __init__(self, bot):
         self.bot: commands.Bot = bot
+        self.poll_server_population.start()
 
     palworld = discord.SlashCommandGroup("palworld", "Palworld related commands")
 
@@ -168,6 +170,22 @@ class PalWorld(commands.Cog):
             "https://img.game8.co/3822502/5ae8382d16bd390dd19f343e87680d51.png/show"
         )
 
+    @tasks.loop(seconds=300)
+    async def poll_server_population(self):
+        # Wait until the bot is ready before we actually start executing code
+        await self.bot.wait_until_ready()
+
+        from source_rcon import SourceRcon
+        from loguru import logger
+
+        logger.disable("source_rcon")
+
+        rcon = SourceRcon("192.168.1.200", 25575, os.getenv("pal_rcon_pass"))
+        num_players = len(rcon.send_command("ShowPlayers").split("\n")[1:-1])
+        # channel = self.bot.get_channel(932476007439552522)
+        channel = self.bot.get_channel(1199397770746925239)
+        await channel.edit(name="Palworlders %s online" % num_players)
+
 
 def setup(bot):
     bot.add_cog(PalWorld(bot))

app/requirements.txt

@@ -13,3 +13,4 @@ requests
 requests-cache
 wolframalpha
 yfinance
+loguru

app/source_rcon.py

@@ -0,0 +1,132 @@
+"""Utility for server administration via source rcon."""
+import socket
+import struct
+
+from dataclasses import dataclass
+
+from loguru import logger
+
+
+@dataclass
+class RconPacket:
+    # https://developer.valvesoftware.com/wiki/Source_RCON_Protocol#Basic_Packet_Structure
+    size: int = None
+    id: int = None
+    type: int = None
+    body: str = None
+    terminator: bytes = b"\x00"
+
+    def pack(self):
+        body_encoded = (
+            self.body.encode("ascii") + self.terminator
+        )  # The packet body field is a null-terminated string encoded in ASCII
+        self.size = (
+            len(body_encoded) + 10
+        )  # Only value that can change is the length of the body, so do len(body) + 10.
+        return (
+            struct.pack("<iii", self.size, self.id, self.type)
+            + body_encoded
+            + self.terminator
+        )
+
+
+@dataclass
+class RCONPacketType:
+    SERVERDATA_AUTH: int = 3
+    SERVERDATA_AUTH_RESPONSE: int = 2
+    SERVERDATA_EXECCOMMAND: int = 2
+    SERVERDATA_RESPONSE_VALUE: int = 0
+
+
+class SourceRcon:
+    def __init__(self, server_ip: str, rcon_port: int, rcon_password: str) -> None:
+        self.SERVER_IP = server_ip
+        self.RCON_PORT = rcon_port
+        self.RCON_PASSWORD = rcon_password
+
+    def create_packet(
+        self, command, request_id=1, type=RCONPacketType.SERVERDATA_EXECCOMMAND
+    ):
+        packet = RconPacket(id=request_id, type=type, body=command)
+        final_packet = packet.pack()
+
+        logger.debug(f"Final packet: {final_packet}")
+        return final_packet
+
+    def receive_all(self, sock, bytes_in: int = 4096):
+        response = b""
+        while True:
+            try:
+                part = sock.recv(bytes_in)
+                if not part:
+                    break
+                response += part
+                if len(part) < bytes_in:
+                    break
+            except socket.error as e:
+                logger.error(f"Error receiving data: {e}")
+                break
+        return response
+
+    def decode_response(self, response):
+        if len(response) < 12:
+            return "Invalid response"
+        size, request_id, type = struct.unpack("<iii", response[:12])
+        if size <= 10:
+            return "No response body or empty response."
+        try:
+            # Decode response with UTF-8
+            body = response[12:-2].decode("utf-8")
+        except UnicodeDecodeError as e:
+            # If UTF-8 decoding fails, use "replace" error handling
+            logger.warning(f"UnicodeDecodeError: {e}")
+            body = response[12:-2].decode("utf-8", errors="replace")
+        return body
+
+    def get_auth_response(self, auth_response_packet):
+        if len(auth_response_packet) < 12:
+            return "Invalid response"
+        size, request_id, type = struct.unpack("<iii", auth_response_packet[:12])
+
+        if type == RCONPacketType.SERVERDATA_AUTH_RESPONSE:
+            # If request_id is -1, authentication failed
+            if request_id == -1:
+                return False
+            else:
+                return True
+        else:
+            logger.error("get_auth_response was given a packet of wrong type.")
+
+    def send_command(self, command):
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            try:
+                s.connect((self.SERVER_IP, self.RCON_PORT))
+            except socket.error as e:
+                logger.error(f"Failed to connect to socket. Error: {e}")
+            else:
+                logger.debug("Connection successful.")
+
+            # Authenticate to server rcon before sending command
+            logger.debug("Authenticating to server rcon before sending command.")
+            auth_packet = self.create_packet(
+                self.RCON_PASSWORD, type=RCONPacketType.SERVERDATA_AUTH
+            )
+            s.sendall(auth_packet)
+
+            # Get and parse authentication response
+            auth_response = self.receive_all(s)
+            if self.get_auth_response(auth_response):
+                logger.debug("Authentication successful.")
+            else:
+                logger.error("Authentication failed. Not running command.")
+                return ""
+
+            # Send command
+            command_packet = self.create_packet(command)
+            s.sendall(command_packet)
+
+            # Get command response
+            response = self.receive_all(s)
+            decoded_response = self.decode_response(response)
+            logger.debug(decoded_response)
+            return decoded_response