mysqli doesn't connect under apache

Question

I have a php application based on codeigniter, and I have a database that is located on remote host with required database installed, setup proper mysql permissions and with mysql port open for remote connections, however, when I run the application it doesn't work and it returns 500 error code.

When I troubleshoot the problem, it gives below error

Message: mysqli::real_connect(): (HY000/2003): Can't connect to MySQL server on '192.168.6.13' (13)

what I have tried so far:

1) make sure all permissions are set correctly.

2) make sure no network related issues are existed such as blocked ports/hosts

3) make sure mysqli is installed and enabled.

4) created a connection test php script and ran it from the command line and it works just fine.

5) the fun part was when I ran the application from command line and it worked correctly as root user and as apache user as su -s /bin/sh apache -c "php index.php".

parameters I have:

1) php version is PHP 5.4.16

2) OS version: CentOS Linux release 7.2.1511 (Core) on both web and DB

3) web server version Apache/2.4.6 (CentOS)

4) mysql Ver 14.14

5) I run my app under ssl, and below is my configurations

<VirtualHost *:443>

        #### Gloabl config
     DocumentRoot /var/www/bein
     DirectoryIndex index.php
     ServerName beinmob.com
     ServerAlias www.beinmob.com
        #### change basic URL to /index.php/POS_Admin/Session
     RewriteEngine  on
     RewriteRule ^/?$  index.php/POS_Admin/Session [R]
        #### change url to alias for web services
     Alias /web-services /var/www/bein/index.php
     Alias /POS_Admin /var/www/bein/
        #### Basic Authentication for /web-services url
        <Location /POS_Admin>
                RewriteEngine on
                # Hide the application and system directories by redirecting the request to index.php
                RewriteBase /index.php
                RewriteRule ^(application|system|\.svn) index.php/$1 [L]
                RewriteCond %{REQUEST_FILENAME} !-f
                RewriteCond %{REQUEST_FILENAME} !-d
                RewriteRule ^(.*)$ index.php/$1 [QSA,L]
        </Location>
        <Location /web-services>
                AuthName bein
                AuthType Basic
                AuthUserFile /etc/httpd/conf.d/beinServicePass
                Require valid-user
        </Location>
        #### SSL configuration
        SSLEngine on
        SSLCertificateFile /etc/httpd/cert/certs/www_beinmob_com.crt
        SSLCertificateKeyFile /etc/httpd/cert/certs/www_beinmob_com.key
        SSLCertificateChainFile /etc/httpd/cert/certs/DigiCertCA.crt
</VirtualHost>

Answer 1

Check this it should solve your problem .

Update because the link may become dead if that page moves or is deleted

Login as root and do

setsebool -P httpd_can_network_connect=1