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

Answer 2

I forgot to listen on PORT 80, fixed it.

"http" part of nginx config, at: /etc/nginx/nginx.conf, is below:

http {
    server {
        listen 192.111.111.11:80;
        location /path1/ {
            proxy_pass http://127.0.0.1:3000/path1/
        }
    }
}

Now, accessing
http://192.111.111.11/path1/
will get result of accessing
http://127.0.0.1:3000/path1/

NOTE:
Replace the 192.111.111.11 with your IP address in the above.
Run "ifconfig" command, the "inet addr" part will give your IP address

Answer 3

This

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

Needs to be this

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

Answer 4

By some reason proxy_pass in Nginx cuts header "Host" before passing to upstream, and request catches by default server, and even proxy_header_pass doesn't helps, so I've to explicitly set it:

location / {
    proxy_set_header Host $host;
    proxy_pass  http://backend;
}