PHP Warning: failed to open stream: HTTP request failed

Question

I have two web servers:

www.example.com.ar and eventos.example.com.ar

I get the errors such as:

[Wed Sep 16 12:11:30.872792 2020] [php7:warn] [pid 17125] [client xx.yy.226.234:48896] PHP Warning: file_get_contents(https://eventos.example.com.ar/eventos/api/events?month=9&year=1999): failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request\r\n in /var/www/www_example_com_ar/wp-content/plugins/example-plugin/mlc-plugin.php on line 340

The line 340th has:

$rest = file_get_contents('https://eventos.example.com.ar/eventos/api/events?month='.$month.'&year='.$year, true);

I've tested with curl on the same host that runs www.example.com.ar and I don't get such an error:

curl -I "https://eventos.example.com.ar/eventos/api/events?month=9&year=1999"
HTTP/1.1 200 OK
Date: Wed, 16 Sep 2020 19:26:05 GMT
Server: Apache/2.4.39 () OpenSSL/1.0.2k-fips
X-DNS-Prefetch-Control: off
X-Frame-Options: SAMEORIGIN
Strict-Transport-Security: max-age=15552000; includeSubDomains
X-Download-Options: noopen
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
Content-Length: 37027
ETag: W/"90a3-gzipB01lW17JrEb0GD0k0g2zFow"

I have installed:

• Apache: httpd-2.4.6-90.el7.centos.x86_64
• PHP: php73-php-7.3.15-1.el7.remi.x86_64

By the way, I have:

php73 -i | grep allow_url_fopen
allow_url_fopen => On => On

On CentOS 7.7

So, the question is: what does it cause that error?

Solution

You can add ignore_errors => true to your file_get_contents call in order to get the full message. That will ignore the error message but you would be able to get more information on what's going on. More information here (And don't forget to remove it after if you want it to break if there is another error.):

https://stackoverflow.com/questions/11475657/ignoring-errors-in-file-get-contents-http-wrapper/11479968#11479968

In my experience, this error is probably because your php doesn't have the root ca certificate in order to validate HTTPS calls. Adding the cacert.pem file to your instance with the configuration in php.ini would fix that issue.

https://stackoverflow.com/questions/41772340/how-do-i-add-a-certificate-authority-to-php-so-the-file-function-trusts-certif

In any case, first thing would be to try to get more information on your error since 400 is can mean a couple of things.

Comments

[Michael Hampton]

But what were $month and $year set to? This looks like it will end up being a bug in your program. We're not able to help with debugging PHP code, but you can ask about that on Stack Overflow.

[sebelk]

You're right, but using curl with the same url reported in the log, doesn't get the HTTP 400 status...

[Michael Hampton]

You should check the logs of the API server.

[dortegaoh]

Is selinux configured to allow outgoing connections for Apache? (By default it is not)