Nginx – Connection refused while connecting to upstream

1. Ensure php-fpm is running (ps auxw | grep php or any number of ways)
2. Ensure php-fpm is actually listening on 9000. (check the configs)
3. Ensure your software firewall isn't blocking loopback connections on 9000.

I'm not an nginx guy, but the error message is pretty clear: nobody's answering the phone at 127.0.0.1:9000

Two additional FastCGI parameters are required.

fastcgi_param SERVER_PORT "80";
fastcgi_param SCRIPT_NAME $fastcgi_script_name;

Credit goes to KnyghtMare from the #mono IRC channel for his test script. By elimination, the required parameters for the nginx conf were found. Usage note: you might have to change the IP and port number on the last line, and HTTP_HOST.

SERVER_SOFTWARE="lighttpd/1.4.26" \
SERVER_NAME="127.0.0.1" \
GATEWAY_INTERFACE="CGI/1.1" \
SERVER_PORT="80" \
SERVER_ADDR="127.0.0.1" \
REMOTE_PORT="28886" \
REMOTE_ADDR="127.0.0.1" \
SCRIPT_NAME="/" \
PATH_INFO="" \
SCRIPT_FILENAME="/var/www/" \
DOCUMENT_ROOT="/var/www/" \
REQUEST_URI="/" \
QUERY_STRING="" \
REQUEST_METHOD="GET" \
REDIRECT_STATUS="200" \
SERVER_PROTOCOL="HTTP/1.1" \
HTTP_HOST="arch" \
HTTP_CONNECTION="keep-alive" \
HTTP_CACHE_CONTROL="max-age=0" \
HTTP_USER_AGENT="Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.83 Safari/535.11" \
HTTP_ACCEPT="text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" \
HTTP_ACCEPT_ENCODING="gzip,deflate" \
HTTP_ACCEPT_LANGUAGE="en-US,en;q=0.8" \
HTTP_ACCEPT_CHARSET="ISO-8859-1,utf-8;q=0.7,*;q=0.3" \
cgi-fcgi -bind -connect 127.0.0.1:9000

After some more modifications to get resource files working, this is the current configuration:

server
{
        listen 80;
        server_name arch;

        access_log /var/www/test/log/access.log;
        error_log /var/www/test/log/error.log debug;

        root /var/www/test/public;

        location /
        {
                try_files $uri @proxy;
        }

        location @proxy
        {
                fastcgi_index /Home;
                fastcgi_pass 127.0.0.1:9000;
                fastcgi_param PATH_INFO "";
                fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                fastcgi_param SERVER_PORT $server_port;
                fastcgi_param SCRIPT_NAME $fastcgi_script_name;
        }
}