Support running docker container via singularity

[keiranmraine]

I realise this would be a relatively large undertaking but having this work with singularity exec would be hugely useful.

[pkerpedjiev]

Hey, thanks for the suggestion! There's actually been a bit of discussion about this on the higlass/higlass repo: higlass/higlass#161

Would be great to have but nobody on the core team has had much experience with Singularity. If you would like to try to implement it, it would be greatly appreciated and I would be happy to help you however I can.

[keiranmraine]

This looks like it will require changes in the docker container too. It appears that the container is by default binding port 80. Under docker that is fine as the user can change the bind. Under singularity you don't have this ability, the default port needs to be non-admin... higlass/higlass-docker#154

(unlikely I would get time to look at this, I've been tasked with getting something up quickly to display Hi-C data matrices, Singularity would have been easier for our users to interface with on our core network, but I've had to do it on OpenStack so I can use the docker version)

[pkerpedjiev]

I see. Thanks for looking into this and the extra information you provided! For what it's worth, the port that nginx listens to in the server is set here: https://github.com/higlass/higlass-docker/blob/60b9c408e71732bfa459847649036aa4228f8ef9/web-context/sites-enabled/hgserver_nginx.conf#L9

This just serves as a proxy for an uwsgi server running on port 8001.