nginx配置php老是出错，最后才发现是$document_root的设置问题。
location ~ \.php$ {
root html;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
这个用出现找不到php的错误。因为$document_root 的参数是由root html那一行定义的，默认是在/etc/nginx/html/ 所以把 html换成站点根目录就正常了。
location ~ \.php$ {
root /usr/share/nginx/html;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}