CentOS Selinux

Install setroubleshoot.noarch to show selinux error messages:

 yum install setroubleshoot-server.noarch setroubleshoot.noarch

Allow Apache to listen to a different port and check which port is selinux allowed:

semanage port -a -t http_port_t -p tcp 81 

semanage port -l

selinux also prevent mysqld to start after relocate /var/lib/mysql to /home/mysql:

 chcon -R -t mysqld_var_run_t /home/mysql 
ll -Z .
-rw-rw----  mysql mysql user_u:object_r:mysqld_var_run_t ibdata1
-rw-rw----  mysql mysql user_u:object_r:mysqld_var_run_t ib_logfile0
-rw-rw----  mysql mysql user_u:object_r:mysqld_var_run_t ib_logfile1
drwx------  mysql mysql user_u:object_r:mysqld_var_run_t mysql
drwx------  mysql mysql user_u:object_r:mysqld_var_run_t test

Allow mysqld to use /home/mysql

# cat /tmp/avc
host=tortoise type=AVC msg=audit(1221459330.317:413): avc: denied { create } for pid=7642 comm="mysqld" name="forum_db" scontext=system_u:system_r:mysqld_t:s0 tcontext=system_u:object_r:mysqld_var_run_t:s0 tclass=dir 
# audit2allow -M local < /tmp/avc 
******************** IMPORTANT ***********************
To make this policy package active, execute:

semodule -i local.pp

# semodule -i local.pp

#audit2allow -M local  -i /var/log/audit/audit.log

httpd access denial, change type to httpd_sys_content_t

chcon -R -t httpd_sys_content_t /var/www/html/