Source:

Places to search for AVC messages:

Messages via Rsyslog are generated with "kern" facility. CentOS default Rsyslog setting is written as "*.info;xxx /var/log/messages", so AVC Denial Log is recorded to /var/log/messages.

    grep "avc: .denied" /var/log/messages

Messages via Auditd are generated to /var/log/audit/audit.log.

    grep "avc: .denied" /var/log/audit/audit.log

For Messages via Auditd, it's possible to search them with ausearch command.

    ausearch -m AVC

For Messages via Auditd, it's possible to show summary reports with aureport command.

    aureport --avc --summary

STAT command to show SE_Linux status:

stat -c "%a %n %C" *

Allow apache to receive files to an uploads folder/directory:

sudo chown apache:apache -R /uploads
sudo chcon -Rv --type=httpd_sys_rw_content_t uploads/

With /srv/ as the base directory you must adjust the SELinux labels.
htdocs is where the index.php/html file goes.

[…]# /usr/sbin/semanage fcontext -a -t httpd_sys_content_t  -s system_u  "/srv/SITENAME/htdocs(/.*)?"
[…]# /sbin/restorecon -R -vF /srv/SITENAME/htdocs
Relabeled /srv/SITENAME/htdocs from unconfined_u:object_r:var_t:s0 to system_u:object_r:httpd_sys_content_t:s0
Source: https://docs.fedoraproject.org/en-US/fedora-server/services/httpd-basic-setup/#_installation

Change the SE Linux properties of a file: (Source: https://www.thegeekstuff.com/2017/07/chcon-command-examples/) Example: this Test2a.php file was displaying "Access Denied" error on my website.

Check and change the SELinux properties:

    Check the current SELinux properties with: ls -Z
        The properties were: unconfined_u:object_r:user_home_t:s0 Test2a.php

    I changed the SELinux properties using:
        sudo chcon unconfined_u:object_r:httpd_user_content_t:s0 Test2a.php

If you want to copy the SE_Linux settings from one directory that is working to another:

    # semanage fcontext --add --equal /var/www/html /opt/www/html
    # restorecon -rv /opt/www/html

If you are using a non-standard directory for web files, like /opt/www/html, then you may not be able to use restorecon to automatically fix the SELinux context. You will have to set the context using chcon and save the change using semanage to make the change permanent:

    # chcon -R system_u:object_r:httpd_sys_content_t:s0 /opt/www
    # semanage fcontext -a -t httpd_sys_content_t "/opt/www(/.*)?"
    # restorecon -rv /opt/www

If you get "SQLSTATE[HY000] [2002] Permission denied" message. You must check in the SELinux if port 80 is managed in. You can check it by typing # semanage port -l | grep http_port_t for a list and check:

        semanage port -l | grep http_port_t

If you need to add the required port, just type:

        # semanage port -a -t http_port_t -p tcp 80

Stop the httpd service set the SE_Linux permission and start the http service.

        Down the httpd service # service httpd stop
        # setsebool -P httpd_can_network_connect 1
        # setsebool -P httpd_can_network_connect_db 1
        Up the httpd service # service httpd start