Add Prometheus metrics to various parts of the bot (#74)

.github/workflows/lint.yml

@@ -24,6 +24,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install click discord.py python-dotenv
+        pip install prometheus_client
         pip install requests sentry_sdk python-logging-loki aiohttp systemd-python
     - name: Install linters
       run: |

cogs/inclusive_language.py

@@ -6,6 +6,7 @@
 from typing import cast, Sequence
 
 import discord
+import prometheus_client  # type: ignore
 from discord.ext import commands
 
 from cogs import base_cog
@@ -42,6 +43,9 @@ def __init__(
     ) -> None:
         super().__init__(**kwargs)
         self.patterns = patterns
+        self.prom_counter = prometheus_client.Counter(
+            "inclusive_language_triggered", "How many times inclusive language was triggered."
+        )
 
     @commands.Cog.listener()
     async def on_message(self, message: discord.Message) -> None:
@@ -54,6 +58,7 @@ async def on_message(self, message: discord.Message) -> None:
         if not any(pattern.search(message.content) for pattern in self.patterns):
             return
         self.usage_stats[message.author.display_name].append(int(time.time()))
+        self.prom_counter.inc()
         if channel.type == discord.ChannelType.public_thread:
             await message.reply(MESSAGE, delete_after=DURATION, suppress_embeds=True)
         elif channel.type == discord.ChannelType.text:

cogs/mentor_requests.py

@@ -6,6 +6,7 @@
 from typing import Sequence
 
 import discord
+import prometheus_client  # type: ignore
 from discord.ext import commands
 from discord.ext import tasks
 from exercism_lib import exercism
@@ -21,6 +22,12 @@
     "get_theads": "SELECT track_slug, message_id FROM track_threads",
     "add_thead": "INSERT INTO track_threads VALUES (:track_slug, :message_id)",
 }
+PROM_TRACK_COUNT = prometheus_client.Gauge("mentor_requests_tracks", "Number of tracks")
+PROM_REQUEST_COUNT = prometheus_client.Gauge("mentor_requests", "Number of requests")
+PROM_UPDATE_HIST = prometheus_client.Histogram("mentor_requests_update", "Update requests")
+PROM_UPDATE_TRACK_HIST = prometheus_client.Histogram(
+    "mentor_requests_update_track", "Update one track", ["track"],
+)
 
 
 class RequestNotifier(base_cog.BaseCog):
@@ -45,10 +52,11 @@ def __init__(
         self.lock = asyncio.Lock()
 
         if tracks:
-            self.tracks = tracks
+            self.tracks = list(tracks)
         else:
             self.tracks = exercism.Exercism().all_tracks()
-            self.tracks.sort()
+        self.tracks.sort()
+        PROM_TRACK_COUNT.set(len(self.tracks))
 
         self.synced_tracks: set[str] = set()
         self.task_update_mentor_requests.start()  # pylint: disable=E1101
@@ -105,6 +113,7 @@ async def update_track_requests(self, track: str) -> dict[str, str]:
                 self.conn.execute(QUERY["add_request"], data)
         return requests
 
+    @PROM_UPDATE_HIST.time()
     async def update_mentor_requests(self) -> None:
         """Update threads with new/expires requests."""
         logger.debug("Start update_mentor_requests()")
@@ -114,7 +123,8 @@ async def update_mentor_requests(self) -> None:
         for track in self.tracks:
             try:
                 async with asyncio.timeout(30):
-                    requests = await self.update_track_requests(track)
+                    with PROM_UPDATE_TRACK_HIST.labels(track).time():
+                        requests = await self.update_track_requests(track)
                     synced_tracks.add(track)
             except asyncio.TimeoutError:
                 logging.warning("update_track_requests timed out for track %s.", track)
@@ -156,6 +166,7 @@ async def update_mentor_requests(self) -> None:
                 except discord.errors.NotFound:
                     logger.info("Message not found; dropping from DB. %s", message.jump_url)
             await asyncio.sleep(0.1)
+        PROM_REQUEST_COUNT.set(len(self.requests))
         logger.debug("End update_mentor_requests()")
 
     @tasks.loop(minutes=10)

cogs/mod_message.py

@@ -7,9 +7,13 @@
 from discord import app_commands
 from discord.ext import commands
 
+import prometheus_client  # type: ignore
 from cogs import base_cog
 
 logger = logging.getLogger(__name__)
+PROM_MESSAGE_COUNTER = prometheus_client.Counter(
+    "mod_message_count", "Mod Message counter", ["message"],
+)
 
 
 class ModMessage(base_cog.BaseCog):
@@ -104,6 +108,7 @@ async def mod_message(
             if mention:
                 content = f"{mention.mention} {content}"
             self.usage_stats[message.value] += 1
+            PROM_MESSAGE_COUNTER.labels("message.value").inc()
             await channel.send(content, suppress_embeds=True)
 
         return mod_message

cogs/track_react.py

@@ -5,13 +5,15 @@
 import re
 
 import discord
+import prometheus_client  # type: ignore
 from discord.ext import commands
 
 from cogs import base_cog
 
 logger = logging.getLogger(__name__)
 
 URL_RE = re.compile(r"https?://\S+")
+PROM_REACT_COUNTER = prometheus_client.Counter("react_count", "Reaction counter", ["emoji"])
 
 
 class TrackReact(base_cog.BaseCog):
@@ -112,6 +114,7 @@ async def add_reacts(self, message: discord.Message, content: str) -> None:
 
         for reaction in reactions:
             self.usage_stats[reaction.name] += 1
+            PROM_REACT_COUNTER.labels(reaction.name).inc()
             await message.add_reaction(reaction)
             await asyncio.sleep(0.1)
 

exercism_discord_bot.py

@@ -14,6 +14,7 @@
 import discord
 import dotenv
 import logging_loki  # type: ignore
+import prometheus_client  # type: ignore
 import sentry_sdk  # type: ignore
 import systemd.journal  # type: ignore
 from discord.ext import commands
@@ -57,6 +58,7 @@ def __init__(
         super().__init__(*args, **kwargs)
         self.cogs_to_load = cogs_to_load
         self.exercism_guild_id = exercism_guild_id
+        self.gauge_cogs_loaded = prometheus_client.Gauge("cogs_loaded", "Number of cogs running")
 
     async def setup_hook(self):
         """Configure the bot with various Cogs."""
@@ -82,6 +84,7 @@ async def setup_hook(self):
             logger.info("Loading cog %s", cog.__name__)
             instance = cog(**combined)
             await self.add_cog(instance, guild=guild)
+            self.gauge_cogs_loaded.inc()
 
     async def on_error(self, event_method, /, *args, **kwargs) -> None:
         """Capture and log errors."""
@@ -211,6 +214,9 @@ def main(
     if not has_setting("DISCORD_TOKEN"):
         raise RuntimeError("Missing DISCORD_TOKEN")
 
+    if find_setting("PROMETHEUS_PORT"):
+        prometheus_client.start_http_server(int(find_setting("PROMETHEUS_PORT")))
+
     # Start the bot.
     intents = discord.Intents.default()
     intents.members = True