When nginx is reverse proxying, the request url does not have a tail / there will be an unexpected jump, and nginx will redirect to the location/path with a tail / by default.
The pit here is: if the server has a listen port, the automatic jump will be Bring this port, in case there is a layer of reverse proxy in front, there will be an accident.
Solution:
1. The front-level reverse proxy is a field without a port number such as a domain name, directly configure port_in_redirect off
2. The front-level reverse proxy is another port, which is embarrassing, you need to configure proxy_pass and redirect manually
location = /xx/ {}
location = /xx {proxy_pass: http://{yours} }