Frappe CORS for nginx

nginx-files.conf

location / {
        rewrite ^(.+)/$ $1 permanent;
        rewrite ^(.+)/index\.html$ $1 permanent;
        rewrite ^(.+)\.html$ $1 permanent;

        # Allow CORS for static files
        add_header Access-Control-Allow-Origin $cors_origin;
        add_header Access-Control-Allow-Methods "GET, OPTIONS";

        location ~* ^/files/.*.(htm|html|svg|xml) {
            add_header Content-disposition "attachment";

            # Allow CORS again, specifically for the above filetypes
            add_header Access-Control-Allow-Origin $cors_origin;
            add_header Access-Control-Allow-Methods "GET, OPTIONS";

            try_files /$site_name/public/$uri @webserver;
        }

        try_files /$site_name/public/$uri @webserver;
}

nginx.conf

location @webserver {
        if ($request_method = 'OPTIONS') {

                add_header 'Access-Control-Allow-Origin' '*';
                add_header 'Access-Control-Allow-Credentials' 'true';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                add_header 'Access-Control-Allow-Headers' 'Authorization,DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
                add_header 'Access-Control-Max-Age' 1728000;
                add_header 'Content-Type' 'text/plain charset=UTF-8';
                add_header 'Content-Length' 0;
                return 204;
        }
        if ($request_method = 'POST') {
                add_header 'Access-Control-Allow-Origin' '*';
                add_header 'Access-Control-Allow-Credentials' 'true';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                add_header 'Access-Control-Allow-Headers' 'Authorization,DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
        }

        if ($request_method = 'GET') {
                add_header 'Access-Control-Allow-Origin' '*';
                add_header 'Access-Control-Allow-Credentials' 'true';
                add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
                add_header 'Access-Control-Allow-Headers' 'Authorization,DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
        }
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Frappe-Site-Name site1.local.com;
        proxy_set_header Host $host;
        proxy_set_header X-Use-X-Accel-Redirect True;
        proxy_read_timeout 120;
        proxy_redirect off;

        proxy_pass  http://frappe-bench-frappe;
}

General note on CORS

• If CORS is enabled your system becomes less secure (allowing wildcard * hosts is not secure)
• Browser to backend calls can only happen over same origin
• Non browser calls do not need CORS enabled. i.e. If python/java/php/android app calls frappe/erpnext there won't be any CORS issue.

This gist is not /etc/nginx/nginx.conf, it should be part of <frappe-bench>/config/nginx.conf

If requests fail with CORS error in browser even after enabling CORS on backend, try to call /api/method/version endpoint, if that works, CORS is enabled and error is due to something else. This happens because CORS is only enabled for success responses

Hi Revant,
I m trying to connect to a 3rd party server using a client script.

The calls (from my ERPNEXT to the 3rd party server) get response and they are working fine "only" when I disable the Chrome security.

If I don't disable the browser security I get :

Access to fetch at 'https://*./connect/token' from origin 'https://my*.erpnext*.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status.

I read your notes and I have your standard Docker Swarm installation (single Bench).
I noticed your mentioned "This gist is not /etc/nginx/nginx.conf, it should be part of /config/nginx.conf"

Does this means that I have to login to the frappe-bench-v13_erpnext-nginx container and add these lines or to another container?

Thanks,