How are servicec enabled during image build?

[nils-ossenbrink]

Hello Matthias,

there is (at least) one thing left which I do not understand: How are the services which I install by copying the service unit files to /lib/systemd/system/ enabled? I recognised that the are enabled by default. How can prevent them for being enabled?

For example this ansible play:

• name: Copy start-vpn-client service file.
  copy:
  src: start-vpn-client.service
  dest: /lib/systemd/system/
  mode: 0644
  owner: root
  group: root

leads to this one after first boot:

/etc/systemd/system/multi-user.target.wants/start-vpn-client.service -> /lib/systemd/system/start-vpn-client.service

How can I prevent edi from adding those links?

Thanks in advance!

Nils

[lueschem]

The enabling of services is done automatically on the first boot (see also systemd-firstboot. On Debian, by default services get enabled if present. Luckily you can change the default behavior by dropping a preset file such as 95-start-vpn-client.preset into the folder /lib/systemd/system-preset. The content of the file would be a single line like disable start-vpn-client.service. Like that the service would remain disabled.

[nils-ossenbrink]

Great. Thanks for that information, I didnt know that. First I suspected edi to do some magic in the background. But by taking a look into the lxc container I saw that there were no links present after creating the image. Now it makes absolutely sense to me :-)