Currently, if a unit file is enabled from outside of the search path,
and that unit has an alias, then the symlink ends up pointing outside of
the search path too. For example:
$ cat /tmp/a.service
[Service]
ExecStart=sleep infinity
[Install]
Alias=b.service
WantedBy=multi-user.target
$ systemctl enable /tmp/a.service
Created symlink /etc/systemd/system/a.service → /tmp/a.service.
Created symlink /etc/systemd/system/b.service → /tmp/a.service.
Created symlink /etc/systemd/system/multi-user.target.wants/a.service → /tmp/a.service.
This then means the alias is treated as a separate unit:
$ systemctl start a.service
$ sudo systemctl status a
● a.service
Loaded: loaded (/etc/systemd/system/a.service; enabled; preset: enabled)
Active: active (running) since Fri 2024-03-15 15:17:49 EDT; 9s ago
Main PID: 769593 (sleep)
Tasks: 1 (limit: 18898)
Memory: 220.0K
CPU: 5ms
CGroup: /system.slice/a.service
└─769593 sleep infinity
Mar 15 15:17:49 six systemd[1]: Started a.service.
$ sudo systemctl status b
○ b.service
Loaded: loaded (/etc/systemd/system/b.service; alias)
Active: inactive (dead)
To fix this, make sure the alias uses a target that is inside the search
path. Since the unit file itself is outside of the search path, a
symlink inside the search path will have been created already. Hence,
just point the alias symlink to that recently created symlink.
Nick Rosbrook
6fec0fed10