====== 'systemd' ======

===== Creating a service handled by 'systemd' =====
:!: This is only a sort of reminder on how to install //Epeios// related daemons on a //Debian// system. It's not a comprehensive documentation about //sytemd//.

==== Unit file ====

To create a service for //systemd//, you have to create a ''.service'' suffixed file in ''/etc/systemd/system/'' which looks like:

<code ini>
[Unit]
Description=<description>
After=network.target

[Service]
ExecStart=<command>
Restart=on-failure

[Install]
WantedBy=multi-user.target
</code>

where ''<description>'' is a string describing the service, and ''<command>'' the command with its arguments to launch the daemon.

Example:

<code ini xdhdq.service>
[Unit]
Description=Demonstration of the XDHTML technology as web application
After=network.target

[Service]
ExecStart=/home/csimon/services/dmnzq /home/csimon/services/dmnzq.xprj
Restart=on-failure

[Install]
WantedBy=multi-user.target
</code>
==== Registering ====

In order to the service to start at boot, you must somehow registering it with following command:

''systemctl enable /etc/systemd/system%%/%%//<service>//.service''

where ''//<service>//'' is the service name.

Example:

''systemctl enable /etc/systemd/system/xdhdq.service''

:!: This does __not__ start the service ; see below for this.

==== Starting/stopping ====

To start a service, use following command:

''systemctl start //<service>//''

where ''//<service>//'' is the service name.

Example: 

''systemctl start xdhdq''

To stop, type ''stop'' instead of ''start''.

It works also with the //System V// ''service'' command instead of ''systemctl''.

==== Unregistering ====

In order to remove the service from the boot sequence, you must somehow unregistering it with following command:

''systemctl disable /etc/systemd/system%%/%%//<service>//.service''

where ''//<service>//'' is the service name.

Example:

''systemctl disable /etc/systemd/system/xdhdq.service''

:!: This does __not__ stop the service ; see above for this.