using shiny-server with nginx

Heya,

The issue is in your proxy_pass configuration. You’re using data-dancer.com:3838, but Shiny Server runs locally on your server, so you should be proxying to localhost or 127.0.0.1, not your domain name.

Here’s the corrected configuration:

server {
    root /var/www/data-dancer.com;
    index index.html;
    server_name data-dancer.com www.data-dancer.com;

    location / {
        proxy_pass http://127.0.0.1:3838;
        proxy_redirect http://127.0.0.1:3838/ $scheme://$host/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_read_timeout 20d;
        proxy_buffering off;
    }

    listen 443 ssl; # managed by Certbot
    listen [::]:443 ssl ipv6only=on; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/data-dancer.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/data-dancer.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}

server {
    if ($host = www.data-dancer.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    if ($host = data-dancer.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    listen 80;
    listen [::]:80;
    server_name data-dancer.com www.data-dancer.com;
    return 404; # managed by Certbot
}

Key Changes Made:

1. Changed proxy_pass: From http://data-dancer.com:3838 to http://127.0.0.1:3838
2. Fixed proxy_redirect: Updated to properly handle redirects
3. Added essential headers: Including Host, X-Real-IP, X-Forwarded-For, and X-Forwarded-Proto
4. Added proxy_buffering off: Better for Shiny apps with real-time updates

Also make sure you have the connection upgrade map defined:

Add this to your main nginx configuration (usually in /etc/nginx/nginx.conf) in the http block:

http {
    # ... other configuration ...
    
    map $http_upgrade $connection_upgrade {
        default upgrade;
        '' close;
    }
    
    # ... rest of configuration ...
}

Before testing, make sure Shiny Server is actually running:

# Check if Shiny Server is running
sudo systemctl status shiny-server

# If not running, start it
sudo systemctl start shiny-server

# Test locally
curl http://localhost:3838

The 504 Gateway Timeout error was occurring because nginx was trying to connect to your domain name instead of the local Shiny Server process. By changing it to 127.0.0.1:3838, nginx will properly proxy requests to the locally running Shiny Server.

Oh and restart your Nginx server as well after the changes