Update modhelp.py

Make a couple of things customizable using environment variables.

src/modhelp/server.py

@@ -1,16 +1,19 @@
 #!/usr/bin/env python3
 from flask import Flask, make_response, request
 import http
+import os
 import re
 import requests
 
-SERVER=None
+SERVER=os.getenv('MODHELP_SERVER')
 # Generate one by right-clicking on the server icon in the sidebar, clicking on
 # "Server Settings" → "Webhooks" → "Create Webhook". You can then select the
 # channel in which the messages should appear. Copy the "Webhook URL" to the
 # following config variable:
 # DISCORD_WEBHOOK="https://discordapp.com/api/webhooks/.../..."
-DISCORD_WEBHOOK=None
+DISCORD_WEBHOOK=os.getenv('MODHELP_DISCORD_WEBHOOK')
+DISCORD_MESSAGE=os.getenv('MODHELP_DISCORD_FORMAT', "<{player_id}:**{player_name}**> {message}")
+DISCORD_MESSAGE_PREFIX=os.getenv('MODHELP_DISCORD_PREFIX')
 
 app = Flask(__name__)
 
@@ -20,6 +23,9 @@ def sanitize(s):
 def no_content():
     return make_response("", http.HTTPStatus.NO_CONTENT)
 
+def sanitize_string_values(dictionary):
+    return {k: v if not isinstance(v, str) else sanitize(v) for k, v in dictionary.items()}
+
 @app.route("/modhelp", methods=['POST'])
 def modhelp():
     json = request.get_json()
@@ -32,11 +38,13 @@ def modhelp():
         user = "{port}".format(**json)
     else:
         user = "{server}:{port}".format(**json)
-    message = "<{player_id}:{player_name}> {message}".format(**json)
+
+    discord_prefix = DISCORD_MESSAGE_PREFIX + " " if DISCORD_MESSAGE_PREFIX is not None else ""
+    discord_message = discord_prefix + DISCORD_MESSAGE.format(**sanitize_string_values(json))
 
     if DISCORD_WEBHOOK:
         try:
-            requests.post(DISCORD_WEBHOOK, data={"username": user, "content": sanitize(message)}).raise_for_status()
+            requests.post(DISCORD_WEBHOOK, data={"username": user, "content": discord_message}).raise_for_status()
         except requests.HTTPError as e:
             print(repr(e))
             raise