| 27 Nov 2022 |
 @me:linj.tech | Arian: your trick works!
pre-device-command = {
description = "pre device command";
wantedBy = [ "cryptsetup.target" ];
wants = [ "cryptsetup-pre.target" ];
before = [ "cryptsetup-pre.target" ];
unitConfig.DefaultDependencies = false;
# serviceConfig = {
# Type = "oneshot";
# RemainAfterExit = true;
# };
script = ''
echo pre-device-command-start
echo pre-device-command-end
'';
};
| 23:01:17 |
 @arianvp:matrix.org | Great | 23:01:46 |
 @elvishjerricco:matrix.org | linj: I'm very curious what you're trying to achieve | 23:01:51 |
| @me:linj.tech | emm, what I want is somewhat weird: generate a keyfile on the fly for luks without storing that keyfile in initrd | 23:03:52 |
| @me:linj.tech | on a vps | 23:04:23 |
| @me:linj.tech | another question: the before = [ "" ] does not seem to work: 59:50 localhost systemd[1]: Reached target Local Encrypted Volumes (Pre). is before 59:50 localhost systemd[1]: pre-device-command.service: Deactivated successfully. in journal | 23:06:13 |
| @me:linj.tech | * another question: the before = [ "cryptsetup-pre.target" ] does not seem to work: 59:50 localhost systemd[1]: Reached target Local Encrypted Volumes (Pre). is before 59:50 localhost systemd[1]: pre-device-command.service: Deactivated successfully. in journal | 23:06:25 |
| @me:linj.tech | In reply to @me:linj.tech
another question: the before = [ "cryptsetup-pre.target" ] does not seem to work: 59:50 localhost systemd[1]: Reached target Local Encrypted Volumes (Pre). is before 59:50 localhost systemd[1]: pre-device-command.service: Deactivated successfully. in journal oneshot does not change this | 23:06:55 |
| @arianvp:matrix.org | there's an easier way to do that I think | 23:10:25 |
| @arianvp:matrix.org | pretty sure you can do this with systemd-repart | 23:16:51 |
| @arianvp:matrix.org | (Using /dev/urandom as the keyfile) | 23:17:12 |
| @me:linj.tech | my keyfile has a pre-defined key in it | 23:18:19 |
| @me:linj.tech | not random | 23:18:29 |
| @me:linj.tech | In reply to @me:linj.tech
oneshot does not change this well, oneshot does make sure my service is before cryptsetup-pre.target. I confirm it with sleep 10 | 23:20:40 |
| @me:linj.tech | thanks | 23:20:53 |
| @me:linj.tech | It's weird that my pre-device-command.service and cryptsetup-pre.target stops after finishing running nixos activation script.
from man systemd.special:
this target (cryptsetup-pre.target) is particularly useful to ensure that a service is shut down only after all encrypted block devices are fully stopped.
| 23:27:01 |
| @me:linj.tech | guess our initrd is not the same as what systemd's manual says | 23:28:06 |
