Add :8090/nginx_status endpoint for monitoring

Author: dtan4

README.md

@@ -17,6 +17,7 @@ $ docker run \
     --rm \
     --name nginx-basic-auth-proxy \
     -p 8080:80 \
+    -p 8090:8090 \
     -e BASIC_AUTH_USERNAME=username \
     -e BASIC_AUTH_PASSWORD=password \
     -e PROXY_PASS=https://www.google.com \
@@ -37,6 +38,18 @@ $ docker-compose up
 # - Password: password
 ```
 
+### Endpoint for monitoring
+
+`:8090/nginx_status` returns the metrics of Nginx.
+
+```sh-session
+$ curl localhost:8090/nginx_status
+Active connections: 1
+server accepts handled requests
+ 8 8 8
+Reading: 0 Writing: 1 Waiting: 0
+```
+
 ## Environment variables
 
 ### Required

docker-compose.yml

@@ -6,6 +6,7 @@ services:
     image: quay.io/dtan4/nginx-basic-auth-proxy:latest
     ports:
       - 8080:80
+      - 8090:8090
     environment:
       - BASIC_AUTH_USERNAME=username
       - BASIC_AUTH_PASSWORD=password

files/nginx.conf.tmpl

@@ -30,4 +30,13 @@ http {
       proxy_set_header Authorization "";
     }
   }
+
+  server {
+    listen 8090;
+
+    location /nginx_status {
+      stub_status on;
+      access_log off;
+    }
+  }
 }