OX is on the verge of releasing Version 7.10. That version will not be supported on (or packaged for) Debian 8 Jessie, but only on Debian 9 Stretch (and of course RedHat and SuSE). On the other hand, 7.8.x will not be supported on (or packaged for) Stretch.
The latest UCS version is 4.3 at the moment. This is based on Debian Stretch.
Therefore the current OX is not supported on UCS 4.3, but according to Open Xchange an Univention, OX 7.8.4 on UCS 4.2 is supported in an environment with 4.3 servers.
So, when your UCS master is running 4.3, you can theoretically run OX on a 4.2 server. This works fine when you installed OX while the master is still on 4.2 or earlier.
In my case, my master was on 4.3. In order to install OX, I set up a server with UC 4.2 and joined it to the master. This already broke on installation but worked in a later step flawlessly.
Next, I started to install OX:
[root@ucsox:~] # univention-app install oxseforucs ... Installing some packages of oxseforucs on ucsmaster.mydomain Password for email@example.com: Going to install OX App Suite (7.8.4-ucs10) (must_have_fitting_ucs_version) The application requires UCS version 4.2. Unable to install oxseforucs. Aborting... Installing master packages for oxseforucs on ucsmaster.mydomain failed!
Oopsie. But consistent:
univention-app list doesn’t show oxseforucs on the master, therefore there are no package sources and no packages. Fsck.
So let’s do this manually:
[root@ucsmaster:~] # ucr set repository/online/component/oxseforucs_20171205095418/description="OX App Suite" \ repository/online/component/oxseforucs_20171205095418/localmirror=false \ repository/online/component/oxseforucs_20171205095418/server="https://appcenter.software-univention.de" \ repository/online/component/oxseforucs_20171205095418/unmaintained='disabled' \ repository/online/component/oxseforucs_20171205095418/version='current' \ repository/online/component/oxseforucs_20171205095418='enabled' [root@ucsmaster:~] # apt-get update [root@ucsmaster:~] # apt-get install univention-ox-common univention-ox-dependencies-master \ univention-ox-directory-integration univention-ox-framework
Now you can install OX on the 4.2 server.
[root@ucsox:~] # univention-app install oxseforucs --do-not-install-master-packages-remotely