ngnix location breaking node (sails) routes - node.js

Question

I have been looking for the correct nginx configuration to achieve a server location (different from /) and get node routes working.
Context
Node application running on http://localhost:1337
Nginx server with proxy_pass pointing to node application
Server location property /app
http requests redirected to https
Nginx config file
server {
listen 80;
server_name domain.com;
return 301 https://$server_name$request_uri;
}
server {
#listen 80 default_server;
#listen [::]:80 default_server;
listen 443 ssl;
server_name domain.com;
# add Strict-Transport-Security to prevent man in the middle attacks
add_header Strict-Transport-Security "max-age=31536000";
ssl_certificate /etc/nginx/ssl/nginx.crt;
ssl_certificate_key /etc/nginx/ssl/nginx.key;
location /app {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass http://127.0.0.1:1337/;
proxy_redirect off;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header X-Forwarded-Proto $scheme;
proxy_cache_key sfs$request_uri$scheme;
}
}
Problem
When navigating to www.domain.com/app I get the correct node home page.
Then, when requesting www.domain.com/app/test, I would expect it to bring me http://localhost:1337/test. That is not happening, I get a 404 not found instead. So, for some reason, the location isn't recognizing node routing.
The curious thing is that if location is / instead of /app, everything is working as expected. Therefore, the problem might be related to the location.
Possible fixes
I've already tried to add a rewrite under location with no luck:
location /app {
rewrite ^/app(.*) /$1 break;
...
}
Do you have an idea of why this could be happening?

Answer 1

If you are trying to map the front-end URI /app/test to the upstream URI /test then you are missing a trailing / on your location directive. Try:
location /app/ {
...
proxy_pass http://127.0.0.1:1337/;
...
}
Notice that both location and proxy_path have a trailing /.
Of course, it means that the URI /app will not work anymore, but you can fix that easily with:
location = /app { rewrite ^ /app/ last; }
or:
location = /app { return 301 /app/; }
See this document for more.