nginx: subdomains, map to 2nd host with multiple ports - nginx-reverse-proxy

Question

I have been looking for an nginx reverse proxy config that can:
receive incoming traffic from my router on port 80, from mydomain.com;
from subdomains, say sd01, sd02, sd03.
i.e. sd01.mydomain.com - then must go via the nginx reverse proxy (host1), and point the request to host2 (all RPi's) behind my router, and be routed to a different port on this host2.
On host2 (ip address say 192.168.1.33), I have docker running several instances of node-red, each container pointing to a different port on host2:
- sd01.mydomain.com to point to 192.168.1.33:1101
- sd02.mydomain.com to point to 192.168.1.33:1102
- sd03.mydomain.com to point to 192.168.1.33:1103
I have seen so many options of doing this on the web, from using
map $subdomain $subdomain_port {
to others, but I cannot get it working. Could someone point me in the right direction please?
And yes, I have added the wildcard * directive on godaddy for the sub domains to point to the fixed ip of my router.

Answer 1

You should use the upstream directive in association with a proxy_pass in the location directive for this.
ie.
upstream sd01 {
server 192.168.1.33:1101;
}
upstream sd02 {
server 192.168.1.33:1102;
}
upstream sd03 {
server 192.168.1.33:1103;
}
server {
listen 80;
listen [::]:80;
root /var/www;
server_name sd01.mydomain.com;
location / {
proxy_pass http://sd01/;
}
}
server {
listen 80;
listen [::]:80;
root /var/www;
server_name sd02.mydomain.com;
location / {
proxy_pass http://sd02/;
}
}
server {
listen 80;
listen [::]:80;
root /var/www;
server_name sd03.mydomain.com;
location / {
proxy_pass http://sd03/;
}
}
Note that if you are using sockets you will need to upgrade the connection for that path:
location /socket/ {
proxy_pass http://socketserverupstream;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_http_version 1.1;
}
This is a similar configuration that I use for all of my servers. You can however refer to the NGINX documentation.

Answer 2

In your nginx configuration file(nginx.conf) do these changes:
server
{
listen 80;
server_name sd01;
location / {
proxy_pass http://127.0.0.1:1101;
}
}
server
{
listen 80;
server_name sd02;
location / {
proxy_pass http://127.0.0.1:1102;
}
}