php-fpm returning empty response to nginx

Question

nginx is connecting to php-fpm over fastcgi, using the standard /etc/nginx/fastcgi_params in the location block.

When connecting to /.status (php-fpm.ini::ping.path) from the command line with cgi-fcgi -bind, the result comes back as expected (X-Powered-By set, response body, etc).

When requesting with nginx, the result comes back empty (X-Powered-By set, no body length or content). nginx returns 200, since it got a "valid" response.

Watching over tcpdump, I've isolated the requests to parity in their FCGI headers (minus user-related env variables still set by the shell.)

Try changing to the user nginx runs as, and rerun the cgi-fcgi -bind test. — Some Linux Nerd, Apr 01 '15 at 00:11
I always screw up NRPE deployments by testing them as root... figured you might have done the same. — Some Linux Nerd, Apr 01 '15 at 00:12

score 13 · Answer 1 · answered Jan 15 '17 at 01:15

The standard factcgi_params file doesn't contain the key line for SCRIPT_FILENAME.

location ~ \.php$ {
                include fastcgi_params;
                fastcgi_split_path_info ^(.+\.php)(/.+)$;
                fastcgi_pass 127.0.0.1:9000;
                fastcgi_index index.php;
                fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
}

Add it and restart nginx.

score 5 · Answer 2 · edited Dec 18 '16 at 08:33

Well, your question is a bit vague. A so called “white screen of death” (WSOD) might be triggered by an endless amount of things. But some things I do if I encounter this:

Activate the following in your php.ini:

display_errors = 1
display_startup_errors = 1
error_log = /path/to/file
error_reporting = -1 ; (the -1 activates absolutely everything)
log_errors = 1

Activate in your php-fpm.conf:
```
error_log = /path/to/file
```
Activate for each php-fpm pool configuration:
```
catch_workers_output = 1
```
Repeat your request and check all logs (incl. nginx error log)
Increase logging level (e.g. debug on nginx)

If nothing of this helps you to pin-down the problem then please post your complete system information and configurations. Nobody is able to give you a precise answer without that.

php-fpm returning empty response to nginx

2 Answers2