revprox.conf

# Map HTTP Forwarded header to a variable we can assign to $backend_url
map $http_forwarded $backend_url {
    default "";
    "~*for=([^;]+);" $1;
}

#Resetting variables
	js_import headers.js;
	js_set $headers_json headers.headers_json;

#Build the main log_format...again
log_format  main  '$remote_addr'
                  '\t$remote_user'
                  '\t$time_local'
                  '\t$request'
                  '\t$status'
                  '\t$body_bytes_sent'
                  '\t$headers_json';

# Configures a reverse proxy server that passes the $backend_url variable containing HTTP Forwarded header info as the backend server address
server {
    listen 80;
    listen 443 ssl;

    #
	access_log /var/log/nginx/logs/server_access.log main;
	error_log /var/log/nginx/logs/server_error.log;

    # SSL/TLS configuration
    ssl_certificate /etc/nginx/ssl/server.crt;
    ssl_certificate_key /etc/nginx/ssl/server.key;

    #Plain old proxy pass to my CloudFlare server
    location / {
        proxy_pass https://domainfronter.pages.dev/;
    }

    #URI wildcard handles all requests
    location /revprox {
        #Passes the Forwarded header for contents to the reverse proxy as the new destination
        proxy_set_header Host $backend_url;

        #Enable javascript logging functions
        js_header_filter headers.headers_json_log;
    }

    #Serve a front page to confirm web server is running
    location /test {
        root /usr/share/nginx/html;
    }
    
    # Configures the error page
    error_page 400 /400.html;
}