Update uwsgi.ini to allow UWSGI_PROCESSES env var to override it

docker/README.md

@@ -39,6 +39,10 @@ variables in `docker/.env`. For example, to disable HTTP request logging, set:
 
     UWSGI_DISABLE_LOGGING=1
 
+To adjust the number of uWSGI processes (for example, to save memory), set:
+
+    UWSGI_PROCESSES=2
+
 Read more about configuring uWSGI in [uWSGI documentation](https://uwsgi-docs.readthedocs.io/en/latest/Configuration.html#environment-variables).
 
 ## TLS Termination

docker/docker-compose.yml

@@ -16,7 +16,7 @@ services:
         dockerfile: docker/Dockerfile
     # To use a pre-built image, remove the above "build" section
     # and uncomment the following line:
-    # image: healthchecks/healthchecks:v2.10
+    # image: healthchecks/healthchecks:v3.0
     env_file:
         - .env
     ports:

docker/uwsgi.ini

@@ -6,6 +6,9 @@ http-socket = :8000
 harakiri = 10
 post-buffering = 16192
 processes = 4
+if-env = UWSGI_PROCESSES
+processes = %(_)
+endif =
 auto-procname
 enable-threads
 threads = 1