nginx revere proxy 503 error

Hi! I wanted to set up a reverse NGINX proxy with mixpanel.


I used the dockerfile provided by them:

FROM nginx
COPY nginx.conf /etc/nginx/nginx.conf

And this configuration:

events {}
http {
    server {
        listen 80 default backlog=16384;
        listen [::]:80 default backlog=16384;

        location /lib.min.js {
            proxy_set_header X-Real-IP $http_x_forwarded_for;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_pass https://cdn.mxpnl.com/libs/mixpanel-2-latest.min.js;
        }

        location /lib.js {
            proxy_set_header X-Real-IP $http_x_forwarded_for;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_pass https://cdn.mxpnl.com/libs/mixpanel-2-latest.js;
        }

        location /decide {
            proxy_set_header Host decide.mixpanel.com;
            proxy_set_header X-Real-IP $http_x_forwarded_for;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_pass https://decide.mixpanel.com/decide;
        }

        location / {
            proxy_set_header Host api.mixpanel.com;
            proxy_set_header X-Real-IP $http_x_forwarded_for;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_pass https://api.mixpanel.com/;
        }
    }
}

I also enabled a custom domain which is verified (reverse-proxy.rizzgpt.app).

However, I'm getting a 503 when I try to load it. Any idea why?

120b5ec5-59d8-4087-84ae-4e0b3d934aa7

do

listen 8080 default backlog=16384;
listen [::]:8080 default backlog=16384;

instead
then set a service variable PORT=8080

gotcha thanks!
it works! thanks!

no problem 🙂

why was that necessary?
just curious

railway had no way of knowing nginx was listening on port 80
so i asked you to have nginx listen on 8080 purely for good practice since 8080 is an unprivlaged port, then you set PORT=8080 to tell railway what port your app listens on

ah i see!
so PORT=8080 is the magic formula here

railway randomly generates a PORT variable for you, normally you want to listen on that, but thats not exactly possible with nginx, so we have to resort to setting a fixed port