Problem:UCS@school Veyon Proxy Reinstallation Error: "docker is to be ignored

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UCS@school Veyon Proxy Reinstallation Error: “docker is to be ignored”

Problem

When attempting to reinstall the ucsschool-veyon-proxy app, specifically with univention-app install ucsschool-veyon-proxy=4.9.1.12-ucs1, the following error occurs:

Cannot use [App(id="ucsschool-veyon-proxy", version="4.9.1.12-ucs1", ucs_version="5.0", server="https://appcenter.software-univention.de")] as docker is to be ignored, yet, only non-docker versions could be found

This error indicates that the system is configured to ignore Docker-based app installations for ucsschool-veyon-proxy, but the available versions are only non-Docker. This creates a conflict preventing the installation.

Solution

The error arises because a UCR (Univention Configuration Registry) variable is set to ignore Docker for the ucsschool-veyon-proxy app. To resolve this, you need to unset this variable, allowing the App Center to properly identify and install the available non-Docker version.

Follow these steps on your UCS master or relevant DC-Slave:

  1. Check the UCR variable:
    First, verify if the appcenter/prudence/docker/ucsschool-veyon-proxy variable is set to yes.

    root@dc-slave:~ # ucr info appcenter/prudence/docker/ucsschool-veyon-proxy
appcenter/prudence/docker/ucsschool-veyon-proxy: yes

  2. Unset the UCR variable:
    If the variable is set to yes, unset it using the ucr unset command.

    root@dc-slave:~ # ucr unset appcenter/prudence/docker/ucsschool-veyon-proxy
Unsetting appcenter/prudence/docker/ucsschool-veyon-proxy

    This command removes the specific configuration that tells the App Center to ignore Docker for this particular app.

  3. List available versions (optional but recommended):
    After unsetting the UCR variable, you can re-list the available ucsschool-veyon-proxy versions to confirm that the App Center can now correctly identify them.

    root@dc-slave:~ # univention-app list ucsschool-veyon-proxy
ucsschool-veyon-proxy
  Name: UCS@school Veyon Proxy
  Versions:
    4.8.3.8
    4.8.3.8-ucs1
    4.9.0.8-ucs1
    4.9.1.12-ucs1
      Installed: test1.uni.schule test2.uni.schule test3.uni.schule test4.uni.schule test5.uni.schule test6.uni.schule test7.uni.schule test8.uni.schule test9.uni.schule

    You should see the list of available versions, including 4.9.1.12-ucs1.

  4. Reinstall the app:
    Now, you can proceed with the reinstallation of ucsschool-veyon-proxy. You no longer need to specify the exact version if you want the latest available one, as univention-app install ucsschool-veyon-proxy will automatically select it.

    root@dc-slave:~ # univention-app install ucsschool-veyon-proxy
Resolving dependencies for ucsschool-veyon-proxy
Going to install UCS@school Veyon Proxy (4.9.1.12-ucs1)
Password for Administrator:

    The installation should now proceed without the “docker is to be ignored” error.