Change DocumentRoot Apache

action:
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "/var/www/html"
# This should be changed to whatever you set DocumentRoot to.

<Directory"/var/www/html">

problem:
service httpd start
Starting httpd (via systemctl):  Job failed. See system logs and 'systemctl status' for details.
                                                           [FAILED]

step:
su
systemctl enable httpd.service
systemctl restart httpd.service
result:
  [root@localhost www]# systemctl enable httpd.service
httpd.service is not a native service, redirecting to /sbin/chkconfig.
Executing /sbin/chkconfig httpd on
[root@localhost www]# systemctl restart httpd.service
Job failed. See system logs and 'systemctl status' for details.
step:
  cat /var/log/messages | grep httpd
resoult:
  SELinux is preventing /usr/sbin/httpd from getattr access on the directory /var/www/html. For complete SELinux messages. run sealert -l 14582266-6a67-49f5-96a7-790b495c2cd6
step:

Q: How do I enable/disable SELinux protection on specific daemons under the targeted policy?

A: Use system-config-selinux, also known as the SELinux

Administration graphical tool, to control the Boolean values of specific daemons. For example, if you need to disable SELinux for Apache to run correctly in your environment, you can disable the value in system-config-selinux. This change disables the transition to the policy defined in apache.te, allowing httpd to remain under regular Linux DAC security.

The getsebool and setsebool commands can also be used, including on systems that do not have the system-config-selinux tool.

  # setsebool -P httpd_read_user_content 1
result [Solved]:
service httpd start
Starting httpd (via systemctl):                            [  OK  ]