Nginx sets HTTP 200 OK on PHP-FPM parse errors

The post Nginx sets HTTP 200 OK on PHP-FPM parse errors appeared first on ma.ttias.be.

Here's an interesting bit of behaviour that I haven't been able to figure out yet. When a PHP error occurs in a PHP-FPM pool, nginx would still reply with a HTTP 200 status code -- indicating everything is OK.

For instance:

php-fpm-error.log:
[error] 24802#0: *7 FastCGI sent in stderr: "PHP message: PHP Parse error:  syntax error, unexpected '<' in test.php on line 3" while reading response header from upstream, client: 127.0.0.1, server: , request: "GET /test.php?time=1421685293 HTTP/1.1"

nginx-access.log:
127.0.0.1 - - [...] "GET /test.php?time=1421685293 HTTP/1.1" 200 110 "-" "curl"

The actual response seen by the client shows the exact same HTTP 200 OK Status code.

$  curl -i localhost/test.php?time=`date +%s`
HTTP/1.1 200 OK
Server: nginx
...

Parse error: syntax error, unexpected '<' in test.php on line 3

Enabling or disabling PHP's display_error option didn't seem to make any difference.

This happens with a default nginx config, using an upstream to pass all requests to the FastCGI PHP-FPM server. FastCGI's fastcgi_intercept_errors is not being set, so it's still the default "off" (meaning nginx won't intercept any logs and should pass them on without modifying).

upstream php_fpm {
  server unix:/var/run/php-fpm/fpm.sock;
}

...

server {
  ...
  location ~ \.php$ {
    fastcgi_split_path_info ^(.+\.php)(.*)$;
    fastcgi_index           index.php;
    fastcgi_param           SCRIPT_FILENAME  $document_root$fastcgi_script_name;
    include                 fastcgi_params;
    fastcgi_read_timeout    30;


    if (-f $request_filename) {
      fastcgi_pass php_fpm;
    }
  }
}

Anyone else noticing this? What's the best practice to let nginx respond with an HTTP 500 Internal Server Error for these kind of PHP-FPM errors? A similar config in Apache responds correctly with an HTTP 500 code.

The post Nginx sets HTTP 200 OK on PHP-FPM parse errors appeared first on ma.ttias.be.