How to manage Apache service

Apache service can be managed using the server binary. Different distributions might use other binary names - Ubuntu uses apache2 while Red Hat uses httpd - which could get confusing. Available options for the binary include starting, restarting, and stopping the service.

Linux and other Unix-based operating systems have also been using scripts and tools to manage services running on their platform. System V. Init scripts were the most prominent while slowly being replaced by systemd. There are also some other tools though they are not as widely used.

In platforms that use systemd, System V. Init scripts are still available for compatibility reasons. There is also a service command that you can use on Red Hat-based Linux distributions that provides the same functionalities.

1. Stop Apache service using Apache binary.

   $ sudo apache2ctl stop
   AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message

2. Start Apache service using System V. Init scripts.

   $ sudo /etc/init.d/apache2 start
   [ ok ] Starting apache2 (via systemctl): apache2.service.

3. Restart Apache service using systemd.

   $ sudo systemctl restart apache2

4. View Apache running status using systemd.

   $ sudo systemctl status apache2
   ● apache2.service - The Apache HTTP Server
      Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset:
      Active: active (running) since Mon 2020-01-06 05:26:10 UTC; 14s ago
        Docs: https://httpd.apache.org/docs/2.4/
     Process: 1846 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCE
    Main PID: 1874 (apache2)
       Tasks: 55 (limit: 4591)
      Memory: 5.7M
      CGroup: /system.slice/apache2.service
              ├─1874 /usr/sbin/apache2 -k start
              ├─1875 /usr/sbin/apache2 -k start
              └─1876 /usr/sbin/apache2 -k start
   
   Jan 06 05:26:10 host systemd[1]: Starting The Apache HTTP Server...
   Jan 06 05:26:10 host apachectl[1846]: AH00558: apache2: Could not reliably deter
   Jan 06 05:26:10 host systemd[1]: Started The Apache HTTP Server.
5. Disable automatically start Apache service during system startup using systemd.

   $ sudo systemctl disable apache2
   Synchronizing state of apache2.service with SysV service script with /lib/systemd/systemd-sysv-install.
   Executing: /lib/systemd/systemd-sysv-install disable apache2
   Removed /etc/systemd/system/multi-user.target.wants/apache2.service.

6. Automatically start Apache service during system startup using systemd.

   $ sudo systemctl enable apache2
   Synchronizing state of apache2.service with SysV service script with /lib/systemd/systemd-sysv-install.
   Executing: /lib/systemd/systemd-sysv-install enable apache2
   Created symlink /etc/systemd/system/multi-user.target.wants/apache2.service → /lib/systemd/system/apache2.service.