Not familiar with gogs, but SSHing into a container is usually not necessary. Should be able to SSH into the host and run docker exec -it commands instead, which is much simpler. If you absolutely have to SSH into the container it should be doable by exposing port 22 on the service and coming up as a tailnet ssh node
Oh for sure wait for someone more knowledgeable to respond then/do your own thing. I’ve not yet gotten much into anything with git since I’m pretty new to all of this. Sorry for the out of place advice!