On 3/27/24 07:29, Andrei Borzenkov wrote:
On Wed, Mar 27, 2024 at 12:35 AM Orion Poplawski <orion@xxxxxxxx> wrote:Sorry this isn't strictly devel - but it is a bit non-standard. I need to automatically unlock an encrypted disk on connection to a machine, with the caveat that I'm not mounting it - instead I want to connect it to a VM. On machines that we do mount the filesystem, having an fstab entry seems to be the key to get the systemd-cryptsetup@luks-UUID service to fire and get the disk decrypted. But lacking that I'm not sure how to get it to trigger. I do have an entry for the disk in /etc/crypttab: luks-16f5b686-8669-407b-920d-427fa8b81328 UUID=16f5b686-8669-407b-920d-427fa8b81328 none _netdev My current plan had been to use a udev rule to attach the disk to the VM: ACTION=="change", SUBSYSTEM=="block", ENV{ID_FS_LABEL}=="WEEKLY", RUN+="/usr/bin/virsh attach-disk VM %E{DEVNAME} sdc --live" But perhaps if I have a unit that was dependent on the cryptsetup service much like a mount unit may have(?) that could get cryptsetup to fire as well. This is with systemd-252-18.el9.x86_64 I tried having a udev rule that started the specific systemd-cryptsetup@luks-UUID service, but that failed:You did not show this rule, so it is hard to guess why it fails.
Sorry, here goes:ACTION=="add", SUBSYSTEM=="block", ENV{DEVTYPE}=="partition", ENV{ID_BUS}=="usb", ENV{ID_FS_TYPE}=="crypto_LUKS", RUN+="cryptsetup-trigger"
# cat /usr/lib/udev/cryptsetup-trigger #!/bin/bash/usr/bin/systemctl restart 'systemd-cryptsetup@luks\x2d'${ID_FS_UUID//-/\\x2d}.service
It failed with:Mar 26 11:49:43 systemd[1]: Unnecessary job was removed for Expansion Linux\x20filesystem. Mar 26 11:49:43 systemd[1]: systemd-cryptsetup@luks\x2d16f5b686\x2d8669\x2d407b\x2d920d\x2d427fa8b81328.service: Bound to unit dev-disk-by\x2duuid-16f5b686\x2d
8669\x2d407b\x2d920d\x2d427fa8b81328.device, but unit isn't active.Mar 26 11:49:43 systemd[1]: Dependency failed for Cryptography Setup for luks-16f5b686-8669-407b-920d-427fa8b81328. Mar 26 11:49:43 systemd[1]: systemd-cryptsetup@luks\x2d16f5b686\x2d8669\x2d407b\x2d920d\x2d427fa8b81328.service: Job systemd-cryptsetup@luks\x2d16f5b686\x2d866 9\x2d407b\x2d920d\x2d427fa8b81328.service/start failed with result 'dependency'. Mar 26 11:49:43 systemd[1]: Reached target Block Device Preparation for /dev/mapper/luks-16f5b686-8669-407b-920d-427fa8b81328. Mar 26 11:49:43 systemd[1]: Stopped target Block Device Preparation for /dev/mapper/luks-16f5b686-8669-407b-920d-427fa8b81328.
Looking at the systemd debug messages for sde1 being attached: Mar 26 14:27:24 systemd[1]: dev-sde1.device: Changed dead -> pluggedMar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2duuid_2d16f5b686_5cx2d8669_5cx2d407b_5cx2d920d_5cx2d427fa8b81328_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484751 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a Mar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2duuid_2d16f5b686_5cx2d8669_5cx2d407b_5cx2d920d_5cx2d427fa8b81328_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484752 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a Mar 26 14:27:24 systemd[1]: dev-disk-by\x2duuid-16f5b686\x2d8669\x2d407b\x2d920d\x2d427fa8b81328.device: Changed dead -> plugged Mar 26 14:27:24 systemd[1]: dev-disk-by\x2dpartuuid-a53e8ff9\x2dcc81\x2d468d\x2dbbee\x2db029df8678d8.device: Changed dead -> plugged Mar 26 14:27:24 systemd[1]: dev-disk-by\x2did-usb\x2dSeagate_Expansion_NA8JP0EX\x2d0:0\x2dpart1.device: Changed dead -> plugged Mar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2duuid_2d16f5b686_5cx2d8669_5cx2d407b_5cx2d920d_5cx2d427fa8b81328_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484753 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a Mar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2duuid_2d16f5b686_5cx2d8669_5cx2d407b_5cx2d920d_5cx2d427fa8b81328_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484754 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a Mar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2dpartlabel_2dLinux_5cx5cx20filesystem_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484764 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a Mar 26 14:27:24 systemd[1]: Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/systemd1/unit/dev_2ddisk_2dby_5cx2dpartlabel_2dLinux_5cx5cx20filesystem_2edevice interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=484765 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
Can I setup a unit that gets started automatically when a particular dev-disk-by-uuid device becomes present?
Thanks. -- Orion Poplawski he/him/his - surely the least important thing about me IT Systems Manager 720-772-5637 NWRA, Boulder/CoRA Office FAX: 303-415-9702 3380 Mitchell Lane orion@xxxxxxxx Boulder, CO 80301 https://www.nwra.com/
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