How to create systemd services for Linux

This guide walks you through setting up Deluge systemd services on Linux.

Ensure Deluge daemon deluged and Web UI deluge-web are installed. Use which to check installation paths and if necessary modify the service file ExecStart lines to point to alternative paths.

Create a service specific user

For security it is best to run a service with a specific user and group. You can create one using the following command:

sudo adduser --system  --gecos "Deluge Service" --disabled-password --group --home /var/lib/deluge deluge

This creates a new system user and group named deluge with no login access and home directory /var/lib/deluge which will be the default location for the config files.

In addition you can add to the deluge group any users you wish to be able to easily manage or access files downloaded by Deluge, for example:

sudo adduser <username> deluge

Daemon (deluged) service

Create the file /etc/systemd/system/deluged.service containing the following:

[Unit]
Description=Deluge Bittorrent Client Daemon
Documentation=man:deluged
After=network-online.target

[Service]
Type=simple
UMask=007

ExecStart=/usr/bin/deluged -d

Restart=on-failure

# Time to wait before forcefully stopped.
TimeoutStopSec=300

[Install]
WantedBy=multi-user.target

User configuration

To run the service using the previously created user e.g. deluge, first create the service configuration directory:

sudo mkdir /etc/systemd/system/deluged.service.d/

Then create a user file /etc/systemd/system/deluged.service.d/user.conf with the following contents:

# Override service user
[Service]
User=deluge
Group=deluge

Start deluged service

Now enable it to start up on boot, start the service and verify it is running:

sudo systemctl enable /etc/systemd/system/deluged.service
sudo systemctl start deluged
sudo systemctl status deluged

Umask for deluged downloaded files

The umask in the service file can be modified to determine access to files downloaded by deluged (also applies to logging files). Some useful access values are detailed as follows:

  • 000 - full access for all users and groups.

  • 007 - only user and group that deluged is running as (e.g. deluge) with no access from any other accounts.

  • 002 - user and group deluged is running as with read-only for all other accounts.

  • 022 - user deluged is running as with read-only for all other accounts.

The service for deluged must be stopped and started instead of just restarted after changes.

Web UI (deluge-web) service

Create the file /etc/systemd/system/deluge-web.service containing the following:

[Unit]
Description=Deluge Bittorrent Client Web Interface
Documentation=man:deluge-web
After=deluged.service
Wants=deluged.service

[Service]
Type=simple
UMask=027

ExecStart=/usr/bin/deluge-web -d

Restart=on-failure

[Install]
WantedBy=multi-user.target

User configuration

To run the service using the previously created user e.g. deluge, first create the service configuration directory:

sudo mkdir /etc/systemd/system/deluge-web.service.d/

Then create a user file /etc/systemd/system/deluge-web.service.d/user.conf with the following contents:

# Override service user
[Service]
User=deluge
Group=deluge

Start deluge-web service

Now enable it to start up on boot, start the service and verify it is running:

sudo systemctl enable /etc/systemd/system/deluge-web.service
sudo systemctl start deluge-web
sudo systemctl status deluge-web

Service logging

Create a log directory for Deluge and give the service user (e.g. deluge), full access:

sudo mkdir -p /var/log/deluge
sudo chown -R deluge:deluge /var/log/deluge
sudo chmod -R 750 /var/log/deluge

The deluge log directory is now configured so that user deluge has full access, group deluge read only and everyone else denied access. The umask specified in the services sets the permission of new log files.

Enable logging in the service files by editing the ExecStart line, appending -l and -L options:

ExecStart=/usr/bin/deluged -d -l /var/log/deluge/daemon.log -L warning

ExecStart=/usr/bin/deluge-web -d -l /var/log/deluge/web.log -L warning

See deluged -h for all available log-levels.

Restart the services:

sudo systemctl daemon-reload
sudo systemctl restart deluged
sudo systemctl restart deluge-web

Log rotation

To enable log rotation append --logrotate to the above ExecStart lines.

Conditionally start deluged for mount points

If you have a USB disk drive or network drive that may not be immediately available on boot or disconnected at random then you may want the deluged service to wait for mount point to be ready before starting. If they are unmounted or disconnected then deluged is stopped. When they become available again deluged is started.

Ensure you have added the correct drive details to fstab or equivalent so they are mounted at boot.

List the available drive mounts:

sudo systemctl -t mount

Look for your mount point in the Description column. Mounts are formatted similar to the mount point with -s replacing /s in the path. e.g.: media-xyz.mount

Modify the [Unit] section of the deluged.service script by adding the details below, substituting xyz.mount for the mount you want the service to depend on:

[Unit]
Description=Deluge Bittorrent Client Daemon
# Start after network and specified mounts are available.
After=network-online.target xyz.mount
Requires=xyz.mount
# Stops deluged if mount points disconnect
BindsTo=xyz.mount

For multiple mount points add a space between additional entries. e.g.:

After=network-online.target xyz.mount abc.mount def.mount

Modify the [Install] section to ensure the deluged service is started when the mount point comes back online:

[Install]
WantedBy=multi-user.target xyz.mount

Reference: systemd.unit