Detailed error logs when app fails to install


in Univention Corporate Server 4.2 erratum 250 there is one detail that caught my eye:

  • Univention now receives more detailed error messages when App installations fail.

Will this information be accessible by the app maintainers so they can improve their apps?


this is not planned at the moment. Also, the more detailed error messages are still quite internal. Prior to erratum 250, we only got the error code (e.g., 425 when the registration of an LDAP schema fails). Now we get this code plus one more detail depending on the error itself (for “425”, it is the exit code of an external function that actually tried to register the file). This is by no means a full log file. And most of the time, these errors relate to some functionality around the App installation process, not the actual installation. E.g., the Docker image could not be downloaded, the LDAP connection could not be established, UCS was unable to start a database for the Docker App.

Furthermore, all of this currently holds only for Docker Apps. Non-Docker Apps do not send any details, although we intend to change that in the future.

That being said, providing details about failed installations may be useful for App maintainers. Would you be able to “pack” any error in your installation routine into one small “error code”? Or extract the important lines of a long log file? Maybe we can think of a way to add this into the error handling.

But this would make at least one more errata update necessary.

Dirk Wiesenthal

Hi Dirk,

Our current logs are quite chatty but having all the required information in a few lines may be more of a challenge. Is there any chance that simply the output of the installation could be captured into a file, this file compressed and somehow made available?

Do I read correctly that there is no way to find out why a docker app has failed to start up? We’re just trying to configure the app.ini to get our app working, but it keeps failing with

15252 actions.start 18-03-01 11:39:47 [ WARNING]: Job for docker-app-kitoma.service failed. See ‘systemctl status docker-app-kitoma.service’ and ‘journalctl -xn’ for details.
15252 actions.start 18-03-01 11:39:47 [ INFO]: Starting docker-app-kitoma (via systemctl): docker-app-kitoma.service failed!
15252 actions.start 18-03-01 11:39:47 [ DEBUG]: /etc/init.d/docker-app-kitoma returned with 1
15252 actions.start.progress 18-03-01 11:39:47 [ DEBUG]: 100
15252 actions.install 18-03-01 11:39:47 [CRITICAL]: Unable to start the container!

Journalctl does not provide further information except that docker has return with an error code.

edamrose from IRC told me to install the app via console

univention-app install --do-not-revert

to gain access to what happend. Will try that.

With the command from #5 there is a /var/lib/docker/containers/CONTAINERID/CONTAINERID-json.log which has more information on what happened during docker init.

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