nginx proxy_pass 404 error, don't understand why

Question

I am trying to pass off all calls to /api to my webservice but I keep getting 404s with the following config. Calls to / return index.html as expected. Does anyone know why?

Answer 1

Just want to remind others that the slash(backend*/*) after your proxy_pass url is very important!

if the config is

location /api/ {
    proxy_pass http://backend;
}

and you visit http://abc.xyz/api/endpoint, you would be direct to http://backend/api/endpoint;

if the config is

location /api/ {
    proxy_pass http://backend/;
}

and you visit http://abc.xyz/api/endpoint, you would be directed to http://backend/endpoint.

That's the difference.

For more, refer to: Nginx reverse proxy return 404