The HowTo works as expected.
Thank you very much @danb35 for your work, also @fausp and @stephdl .
I wasn’t successful with collabora, but this is much more than just good enough for me!!
One little thing to mention: I use a second NS-instance as fw/gateway/proxy with own certs. To install the onlyoffice-app in nextcloud, I had to add the nextcloud-instance to the “hosts without proxy section” on my gateway. Otherwise I got a failure, that nextcloud couldn’t communicate with the download-server.
Don’t know if it would be better to split nginx and onlyoffice like
nethserver-nginx: to have nginx setup in NethServer next to apache without port conflicts. I’ve seen some threads about nginx being used for different apps or advanced reverse proxy functions and there’s a feature request too:
nethserver-onlyoffice: just to get onlyoffice documentserver integrated - requirement: nethserver-nginx
Because, according to the instruction page at onlyoffice.com, the package from epel doesn’t install a suitably-recent version. OTOH, it also says that with respect to nginx, and the epel version of nginx is just fine.
So now that we have it working, is it possible to make it work without opening another port to the outside? I think Apache has some proxy functionality; couldn’t that be used to proxy https://neth_fqdn/documentserver to https://neth_fqdn:8082? I doubt it’d do anything for security, but it’d be helpful when dealing with firewalls that block non-standard ports.