nginx trouble loading index file - php

Question

I have this nginx vhost file
server { # php/fastcgi
listen 80;
server_name trinityplex.com www.trinity.com;
access_log /home/web/trinity_web/log/access.log;
root /home/web/trinity_web/public;
location / {
index index.html index.htm index.php;
}
}
(for domain trinityplex.com), but if I go to trinityplex.com nginx display me 502 Bad gateway and throws the index file - chrome download index.php like a normal download.
It's ridiculous I have never seen that. If I ask PHP for version it dumps
PHP 5.3.5-0.dotdeb.0 with Suhosin-Patch (cli) (built: Jan 7 2011 00:30:52)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with Suhosin v0.9.32.1, Copyright (c) 2007-2010, by SektionEins GmbH
Have you any ideas how to fix that?
Here is an nginx cofig file
user root;
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
server_names_hash_bucket_size 128;
gzip on;
include /usr/local/nginx/sites-enabled/*;
}

Answer 1

You haven't configured PHP in the server section so PHP files will obviously be sent as plain text. How are you planning to run PHP? As FastCGI?
Update: The configuration you have shown here does still not include anything at all about PHP or FastCGI. Try something like this:
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ .php$ {
fastcgi_pass 127.0.0.1:9000;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_index index.php;
include fastcgi_params;
}