Running Jenkins behind a Nginx Proxy on Plesk

Running Jenkins on a Plesk Server is very easy.
Drop this in the Additional nginx directives Field in the Apache & NGINX Settings of your (Sub)Domain. This basically tells nginx to pass all Traffic to the Jenkins Instance. In this Example Jenkins is running on 127.0.0.1:8001, you'll need to change that according to your Jenkins config.

location ~ / {
	proxy_set_header        Host $host:$server_port;
	proxy_set_header        X-Real-IP $remote_addr;
	proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
	proxy_set_header        X-Forwarded-Proto $scheme;
	proxy_redirect          http:// https://;
	proxy_pass              http://127.0.0.1:8001;
	proxy_http_version 1.1;
	proxy_request_buffering off;
}

I would also recommend to Disable the "Proxymodus" in the Plesk settings since its designed to Proxy the Request to Apache.