customize gunicorn worker count

Procfile

@@ -1,3 +1,3 @@
-web: gunicorn takahe.wsgi:application --workers 8
+web: gunicorn takahe.wsgi:application --workers ${TAKAHE_WORKERS:-8}
 worker: python manage.py runstator
 release: python manage.py migrate

docker/Dockerfile

@@ -50,7 +50,6 @@ RUN TAKAHE_DATABASE_SERVER="postgres://x@example.com/x" TAKAHE_SECRET_KEY="takah
 
 EXPOSE 8000
 
-# Set some sensible defaults
-ENV GUNICORN_CMD_ARGS="--workers 8"
+ENV GUNICORN_CMD_ARGS=""
 
 CMD ["bash", "docker/run.sh"]

docker/run.sh

@@ -12,7 +12,7 @@ sed "s/__CACHESIZE__/${CACHE_SIZE}/g" /etc/nginx/conf.d/default.conf.tpl | sed "
 # Run nginx and gunicorn
 nginx &
 
-gunicorn takahe.wsgi:application -b 0.0.0.0:8001 $GUNICORN_EXTRA_CMD_ARGS &
+gunicorn takahe.wsgi:application -b 0.0.0.0:8001 --workers ${TAKAHE_WORKERS:-8} $GUNICORN_EXTRA_CMD_ARGS &
 
 # Wait for any process to exit
 wait -n

docs/tuning.rst

@@ -9,7 +9,6 @@ We recommend that all installations are run behind a CDN, and
 have caches configured. See below for more details on each.
 
 
-
 Scaling
 -------
 
@@ -30,6 +29,13 @@ using more resources if you give them to it), you can:
   a "celebrity" or other popular account will give Stator a lot of work as it
   has to send a copy of each of their posts to every follower, separately.
 
+* Takahe is run with Gunicorn which spawns several
+  [workers](https://docs.gunicorn.org/en/stable/settings.html#workers)to
+  handle requests. Depending on what environment you are running Takahe on,
+  you might want to customize the worker count via the `TAHAKE_WORKERS`
+  environment variable. The default is `8`.
+
+
 As you scale up the number of containers, keep the PostgreSQL connection limit
 in mind; this is generally the first thing that will fail, as Stator workers in
 particular are quite connection-hungry (the parallel nature of their internal