We installed Zammad on an UCS master. It start properly, but it can’t connect to external systems. It can neither connect to the UCS LDAP server (on the same machine), nor to an external mailserver. The error message is:
An error occurred: Can't connect to 'univention.foo.bar' on port '7389', getaddrinfo: Temporary failure in name resolution
For the mailserver it’s also
getaddrinfo: Temporary failure in name resolution.
It is mentioned here that this may happen, but for us a restart of the app does not help.
No idea if this is the correct way to check it on the command line, but it also fails:
root@univention:~# docker exec zammad_zammad-railsserver_1 ping sz.de ping: sz.de: Temporary failure in name resolution