I came across a guide to set up Collabora Online Development Edition (CODE) as a docker container, in order to enable creation and editing of office documents inside Nextcloud. Just like Google Docs, but in the own cloud.
The guide however focuses on a setup with apache as reverse proxy and a Let's Encrypt SSL certificate.
I'm using nginx and want the SSL connection to end at the reverse proxy, fowarding the connection to the docker container through regular http - therefore dealing with the whole SSL thing at the nginx level.
Nextcloud has itself a guide on how to configure nginx as a reverse proxy, which I used.
Finally, Collabora Office also has a guide on how to set up nginx as a reverse proxy. From there I learned that there are 3 different possible setups : SSL on both ends SSL terminates at the proxy * Plain HTTP
My setup is actually the 2nd, so I learned that The corresponding loolwsd settings are ssl.enable=false and ssl.termination=true.
Which leads me to the docker call :
docker run -t -d -p 127.0.0.1:9980:9980 -e 'domain=my\\.doma\\.in' -e "username=collaboraAdminUser" -e "password=myPassWord" -e "extra_params=--o:ssl.enable=false --o:ssl.termination=true" --restart always --cap-add MKNOD collabora/code