chore: update uwsgi configuration

Allows controlling amount of uwsgi processes using
environment variables.

Also copies some good configuration from other projects.

Refs: HP-2134

.prod/uwsgi.ini

@@ -1,4 +1,5 @@
 [uwsgi]
+# https://uwsgi-docs.readthedocs.io/en/latest/Options.html
 http-socket = :8000
 chdir = /app
 mount = $(APP_URL_PATH)=tunnistamo/wsgi.py
@@ -7,7 +8,28 @@ static-map = $(MEDIA_URL_ROOTLESS)=$(MEDIA_ROOT)
 static-map = $(STATIC_URL_ROOTLESS)=$(STATIC_ROOT)
 uid = appuser
 gid = appuser
+enable-threads = true
+master = true
+processes = $(UWSGI_PROCESSES)
+threads = $(UWSGI_THREADS)
+
+# by default uwsgi reloads on SIGTERM instead of terminating
+# this makes container slow to stop, so we change it here
+die-on-term = true
+harakiri = 20
+harakiri-graceful-timeout = 5
+# Default listen queue is 100
+harakiri-queue-threshold = 80
 buffer-size = 32768
-master = 1
-processes = 2
-threads = 2
+
+# Reload workers regularly to keep memory fresh
+# and ease potential memory leaks
+max-requests = 1000       # Restart workers after this many requests
+reload-on-rss = 300       # Restart workers after this much resident memory
+worker-reload-mercy = 60  # How long to wait before forcefully killing workers (default is 60)
+
+# Suppress errors about clients closing sockets, happens with nginx as the ingress when
+# http pipes are closed before workers has had the time to serve content to the pipe
+ignore-sigpipe = true
+ignore-write-errors = true
+disable-write-exception = true

docker-entrypoint.sh

@@ -92,6 +92,9 @@ if [[ ! -z "$@" ]]; then
 elif [[ "$DEV_SERVER" = "1" ]]; then
     python ./manage.py runserver 0.0.0.0:8000
 else
+    export UWSGI_THREADS=${UWSGI_THREADS:-1}
+    export UWSGI_PROCESSES=${UWSGI_PROCESSES:-4}
+
     # We want to have a *_URL environment variables configure
     # both Django static/media files URL generation
     # and the corresponding file serving in uWSGI.