flatcar-update - Error: update failed

[cpswan]

Description

When running sudo flatcar-update --to-version "3139.2.1" the console output first shows:

Forcing update...

Which is great, but then:

Error: update failed

Without any further explanation of why the update failed, or what can be done to fix that.

I've also tried sudo flatcar-update --to-version "3139.2.1" --to-payload /var/tmp/update_payload but the outcome doesn't change.

Impact

Preventing the update of patched 3139.2.0 nodes to 3139.2.1

Environment and steps to reproduce

1. Set-up: Flatcar Container Linux by Kinvolk stable 2022.04.07+dev-flatcar-master-5373 for Google Compute Engine, which was created by @jepio to deal with oem-gce.service is broken after upgrading to flatcar 3139.2.0 #714
2. Task: update to latest stable release
3. Action(s): sudo flatcar-update --to-version "3139.2.1"
4. Error: Error: update failed

Expected behavior

Update is made ready, and takes place on next reboot.

If flatcar-update hits a problem it presents an error message that gives some clue about what should be done to remove that problem.

Additional information

Running sudo update_engine_client -status I get:

I0530 15:38:14.290454  2224 update_engine_client.cc:241] Querying Update Engine status...
LAST_CHECKED_TIME=1653924489
PROGRESS=0.000000
CURRENT_OP=UPDATE_STATUS_IDLE
NEW_VERSION=0.0.0
NEW_SIZE=0

Doing the same whilst Forcing update... shows gets:

I0530 15:39:01.214694  2382 update_engine_client.cc:241] Querying Update Engine status...
LAST_CHECKED_TIME=1653925138
PROGRESS=0.000000
CURRENT_OP=UPDATE_STATUS_UPDATE_AVAILABLE
NEW_VERSION=3139.2.1
NEW_SIZE=344544962

But once Error: update failed comes up, we're back to:

I0530 15:39:47.871093  2419 update_engine_client.cc:241] Querying Update Engine status...
LAST_CHECKED_TIME=1653925138
PROGRESS=0.000000
CURRENT_OP=UPDATE_STATUS_IDLE
NEW_VERSION=0.0.0
NEW_SIZE=0

[pothos]

The dev build image that you have installed doesn't use the production update signing key, thus I guess you'll find some error message about it in journalctl -u update-engine. The solution is to force using the production update signing key:

sudo flatcar-update --to-version "3139.2.1" --force-flatcar-key

[cpswan]

Thanks @pothos that did it, though many (most) of them needed:

sudo flatcar-update --to-version "3139.2.1" --force-flatcar-key --to-payload /var/tmp/update_payload

I'll open a fresh feature request suggesting the journalctl stuff be added to the error message.