Virtualenv Systemd Service

app_virtualenv.service

[Unit]
Description=Python Virtualenv service example
After=network.target

[Service]
User=my_user
Group=my_group
Environment=VIRTUAL_ENV=/home/my_user/.virtualenvs/my_venv
Environment=PATH=$VIRTUAL_ENV/bin:$PATH
ExecStart=$VIRTUAL_ENV/bin/my_entrypoint
Restart=always

[Install]
WantedBy=multi-user.target

I just stumbled onto this… I wonder, this can't work, right? ExecStart paths have to be absolute, after all…

@jcaesar you are right: I'm getting the following error (when trying to start the unit):

systemd[1]: Executable path is not absolute, ignoring: $VIRTUAL_ENV/bin/my_entrypoint
systemd[1]: Service lacks both ExecStart= and ExecStop= setting. Refusing.

So a fix would be:

- ExecStart=$VIRTUAL_ENV/bin/my_entrypoint
+ ExecStart=/home/my_user/.virtualenvs/my_venv/bin/my_entrypoint

See also: https://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStart=

Systemd does not expand environment variables.
You end up with literal $VIRTUAL_ENV and $PATH inside the PATH variable
and in path to the executable.