Document nginx configuration

README.md

@@ -33,6 +33,27 @@ Instead of flags all the params can be passed as env variables. See the names be
 ./cicer -h
 ```
 
+### nginx configuration
+
+The android app requires CORS to be configured in the server:
+
+```
+location / {
+        if ($request_method ~ ^(OPTIONS)$ ) {
+                add_header Access-Control-Allow-Origin *;
+                add_header Access-Control-Allow-Methods 'GET, POST, PUT, DELETE, OPTIONS';
+                add_header Access-Control-Allow-Headers x-authentication;
+                return 200;
+        }
+
+        add_header Access-Control-Allow-Origin * always;
+        add_header Access-Control-Allow-Methods 'GET, POST, PUT, DELETE, OPTIONS';
+        add_header Access-Control-Allow-Headers x-authentication always;
+
+        proxy_pass http://localhost:8000;
+}
+```
+
 ## Running it for development
 
 To run Cicer in development mode, build and run the backend: