Set env files explicitly

docker-compose.production.yml

@@ -5,13 +5,23 @@ volumes:
   static-files:
 
 services:
+  db:
+    env_file: ./.production.env
+
+  celery:
+    env_file: ./.production.env
+
+  django:
+    env_file: ./.production.env
+
   nginx:
     image: nginx:1.23
     depends_on:
       django:
         condition: service_healthy
-    env_file: ./.env
+    env_file: ./.production.env
     ports:
+      # Note that --env-file should be used to set these correctly
       - "${NGINX_HTTP_PORT:-80}:80"
     volumes:
       - ./config/nginx/conf.d:/etc/nginx/conf.d