remove custom env var and update docs

Procfile

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

docker/Dockerfile

@@ -50,6 +50,7 @@ RUN TAKAHE_DATABASE_SERVER="postgres://x@example.com/x" TAKAHE_SECRET_KEY="takah
 
 EXPOSE 8000
 
-ENV GUNICORN_CMD_ARGS=""
+# Set some sensible defaults
+ENV GUNICORN_CMD_ARGS="--workers 8"
 
 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 --workers ${TAKAHE_WORKERS:-8} $GUNICORN_EXTRA_CMD_ARGS &
+gunicorn takahe.wsgi:application -b 0.0.0.0:8001 $GUNICORN_EXTRA_CMD_ARGS &
 
 # Wait for any process to exit
 wait -n

docs/tuning.rst

@@ -32,8 +32,9 @@ using more resources if you give them to it), you can:
 * 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`.
+  you might want to customize this via the ``GUNICORN_CMD_ARGS`` environment
+  variable. For example - ``GUNICORN_CMD_ARGS="--workers 2"`` to set the
+  worker count to 2.
 
 
 As you scale up the number of containers, keep the PostgreSQL connection limit