/lib/systemd/system/apt-daily.service is in apt 1.2.10ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | [Unit]
Description=Daily apt activities
Documentation=man:apt(8)
[Service]
Type=oneshot
ExecStart=/usr/lib/apt/apt.systemd.daily
|