* Fixed metrics generation

docker/bot/dev.Dockerfile

@@ -3,4 +3,5 @@ RUN apk update && apk add postgresql-dev gcc python3-dev musl-dev libffi-dev
 WORKDIR /merci-bot
 COPY . .
 RUN pip install -r requirements.txt
+RUN mkdir -p /multiprocprometheus
 CMD ["python", "-m", "thankyou.slackbot"]

docker/bot/gunicorn.Dockerfile

@@ -3,4 +3,11 @@ RUN apk update && apk add postgresql-dev gcc python3-dev musl-dev libffi-dev
 WORKDIR /merci-bot
 COPY . .
 RUN pip install -r requirements.txt
-CMD ["gunicorn", "--worker-class=sync", "--worker-connections=100", "--workers", "5", "--bind", "unix:/nginx_sockets/merci_bot.sock", "thankyou.slackbot.utils.wsgi:slack_app()"]
+RUN mkdir -p /multiprocprometheus
+CMD ["gunicorn", \
+        "--worker-class=sync", \
+        "--worker-connections=100", \
+        "--workers", "5", \
+        "--bind", "unix:/nginx_sockets/merci_bot.sock", \
+        "--config=thankyou/slackbot/utils/gunicorn_conf.py", \
+    "thankyou.slackbot.utils.wsgi:slack_app()"]

docker/docker-compose.common.yml

@@ -58,6 +58,7 @@ services:
       SLACK_APP_TOKEN: ${SLACK_APP_TOKEN}
       DATABASE_ENCRYPTION_SECRET_KEY: ${DATABASE_ENCRYPTION_SECRET_KEY}
       MERCI_ENV: ${MERCI_ENV}
+      PROMETHEUS_MULTIPROC_DIR: /multiprocprometheus
     labels:
       logging: "promtail"
       logging_jobname: "merci-bot"

thankyou/slackbot/utils/app.py

@@ -6,7 +6,6 @@
 from typing import Callable
 
 from prometheus_client import Histogram
-from prometheus_client.utils import INF
 from slack_bolt import App
 from slack_sdk import WebClient
 
@@ -80,7 +79,6 @@ def is_socket_mode() -> bool:
     name='slack_handler_metric_histogram',
     documentation='Time spent processing request',
     labelnames=["merci_handler", "merci_handler_type"],
-    # buckets=(.1, .2, .5, .75, 1.0, 2.0, 5.0, 10.0, INF)
 )
 
 
@@ -116,7 +114,7 @@ def wrapper(*args, **kwargs):
             try:
                 return func(*args, **kwargs)
             finally:
-                logger.info(f"Sending metrics for {func.__name__}")
+                # logger.info(f"Sending metrics for {func.__name__}")
                 metric_wrapper.observe(time.time() - now)
 
         return wrapper

thankyou/slackbot/utils/gunicorn_conf.py

@@ -0,0 +1,3 @@
+def worker_exit(server, worker):
+    from prometheus_client import multiprocess
+    multiprocess.mark_process_dead(worker.pid)

thankyou/slackbot/utils/wsgi.py

@@ -1,7 +1,6 @@
 from flask import Flask, request, Response
-from prometheus_client import make_wsgi_app, start_http_server
+from prometheus_client import CollectorRegistry, multiprocess, generate_latest, CONTENT_TYPE_LATEST
 from slack_bolt.adapter.flask import SlackRequestHandler
-from werkzeug.middleware.dispatcher import DispatcherMiddleware
 
 from thankyou.dao import dao
 from thankyou.slackbot.utils.app import app
@@ -17,9 +16,19 @@ def create_flask_app(slack_app_):
 
     dao.set_scoped_session(flask_scoped_session(dao.session_maker, flask_app))
 
-    flask_app.wsgi_app = DispatcherMiddleware(flask_app.wsgi_app, {
-        '/metrics': make_wsgi_app()
-    })
+    @flask_app.route("/metrics")
+    def metrics():
+        registry = CollectorRegistry()
+        multiprocess.MultiProcessCollector(registry)
+        data = generate_latest(registry)
+        return Response(data, mimetype=CONTENT_TYPE_LATEST)
+
+    @flask_app.route("/slack/metrics")
+    def slack_metrics():
+        registry = CollectorRegistry()
+        multiprocess.MultiProcessCollector(registry)
+        data = generate_latest(registry)
+        return Response(data, mimetype=CONTENT_TYPE_LATEST)
 
     @flask_app.route("/slack/events", methods=["POST"])
     def slack_events():