nginx reverse load assets from foo.bar/app properly - docker

Question

i have a webapplication running in a docker container behind nginx reverse proxy on the same container network.
the nginx is set up so that foo.bar/app redirect to the container but application seems to try load resources from foo.bar/. i have tried to do what is documented here:https://www.nginx.com/resources/wiki/start/topics/examples/likeapache/
as a result my location block looked like this:
location /app {
root /app;
proxy_set_header X-Forwarded-Host $host:$server_port;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://webapp/;
}
where webapp is the name of the webapp's docker container in the network

Answer 1

for the location block this is fine
location /app {
proxy_set_header X-Forwarded-Host $host:$server_port;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://webapp/;
}
the trick is to access with a trailing slash so with foo.bar/app/ rather than with foo.bar/app
additionally adding this line will add the trailing slash automagically:
rewrite ^([^.]*[^/])$ $1/ permanent