Services

1. Create the Custom Service File

sudo nano /etc/systemd/system/mycustom.service

2. Edit the Service File

[Unit]
Description=My Custom Script Service
After=network.target

[Service]
ExecStart=/opt/myscript.sh --arg1 value1 --arg2 value2
Type=simple
Restart=on-failure
StandardOutput=file:/var/log/myscript.log
StandardError=file:/var/log/myscript.log

[Install]
WantedBy=multi-user.target

where:

• Description=My Custom Script Service: A short text describing what the service does.

• After=network.target: Ensures the service starts only after the network is up.

• ExecStart=/opt/myscript.sh --arg1 value1 --arg2 value2: Defines the command (with arguments) that runs when the service starts.

• Type=simple: Assumes the command runs in the foreground and doesn't fork.

• Restart=on-failure: Automatically restarts the service if it crashes or exits with an error.

• StandardOutput=file:/var/log/myscript.log: Redirects standard output (stdout) to a log file (though not always fully supported).

• StandardError=file:/var/log/myscript.log: Redirects standard error (stderr) to the same log file.

• WantedBy=multi-user.target: Allows the service to be enabled at boot in multi-user mode (non-GUI).

Configuration options

[Unit]

Defines metadata and ordering dependencies.

Option	Description
Description	A human-readable description (you already have this)
After	Specifies when the unit should start in relation to others (already used)
Requires	Specifies units that must be active for this unit to start
Wants	Like Requires, but failure of these units won’t stop this one
Before	Opposite of After, declares ordering priority
ConditionPathExists	Only start if a specified file exists
Conflicts	If these units are started, this unit is stopped (and vice versa)

[Service]

Core configuration of the service.

Option	Description
ExecStartPre	Commands to run before ExecStart
ExecStartPost	Commands to run after ExecStart
ExecStart	Command that runs when the service starts (must be a full path)
ExecStop	Command to run when stopping the service.
ExecReload	Command for reloading (e.g., re-reading config files)
WorkingDirectory	Set the working directory for the service
User	and Group: Run the service as a specific user or group
Type	Tells systemd how the service starts and runs (e.g., simple, forking)
Environment	Set environment variables
EnvironmentFile	Load environment variables from a file
TimeoutStartSec	How long to wait for ExecStart to finish
TimeoutStopSec	How long to wait before force-stopping
Restart	Defines when the service should restart (e.g., on-failure, always)
RestartSec	Time to wait before restarting
StartLimitBurst	/ StartLimitIntervalSec: Rate-limiting for restarts
KillMode	How processes are killed (e.g., control-group, process)
KillSignal	Signal to send on stop (SIGTERM, SIGKILL, etc.)
StandardInput	Can be tty, file:/path, etc.
StandardOutput	Can be journal, syslog, null, or file:/path (redirection to file not fully supported in all versions of systemd ➡️ Use ExecStart output redirection inside a wrapper script for best reliability)
StandardError	Can be journal, syslog, null, or file:/path

[Install]

Controls enable/disable behavior.

Option	Description
WantedBy	Targets this unit should be enabled for
RequiredBy	Stronger than WantedBy, implies failure if unit fails

3. Reload systemd configuration and start the Service

sudo systemctl daemon-reload
sudo systemctl start myscript.service

4. Enable the Service (Optional)

To start a service automatically on boot, enable it:

sudo systemctl enable myscript.service

5. Check the Status of a service

sudo systemctl status myscript.service