Can't reverse proxy Node backend using Nginx - node.js

Question

I'm working with Angular11 + NodeJS on AWS EC2.
I'm trying to set up a reverse proxy using nginx.
nginx:
server {
listen 80;
listen [::]:80;
server_name http://MY-AWS-IP.com;
root /home/ubuntu/dashboard/frontend/dist/frontangular;
server_tokens off;
index index.html index.htm;
location /auth/ {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /groceries/ {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
node: (running on pm2)
... Some stuff
const ports = process.env.PORT || 3000;
app.use("/groceries", groceryRoutes);
app.use("/auth", loginRoutes);
app.listen(ports, () => console.log(`listening on port ${ports}`));
When trying to login # homepage:
error:
POST http://localhost:3000/auth/login net::ERR_CONNECTION_REFUSED
ERROR
kd {headers: dd, status: 0, statusText: "Unknown Error", url: "http://localhost:3000/auth/login", ok: false, …}
error: ProgressEvent {isTrusted: true, lengthComputable: false, loaded: 0, total: 0, type: "error", …}
headers: dd {normalizedNames: Map(0), lazyUpdate: null, headers: Map(0)}
message: "Http failure response for http://localhost:3000/auth/login: 0 Unknown Error"
name: "HttpErrorResponse"
ok: false
status: 0
statusText: "Unknown Error"
url: "http://localhost:3000/auth/login"
__proto__: wd
I didn't undertand this reverse proxy at all, I thought I should point my app routes.
Thanks!

Answer 1

You just need this much:
server {
listen 80;
listen [::]:80;
server_name http://MY-AWS-IP.com;
root /home/ubuntu/dashboard/frontend/dist/frontangular;
server_tokens off;
index index.html index.htm;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
You would need to set up different location blocks only if they are going to be handled by a different server, probably running on a different port.