Build docker that depends on internal github repo

[zhuchcn]

We have a tool uclahs-cds/private-MSPtools that I recently want to add our internal uclahs-cds/private-moPepGen to its dependency list.

Some package managers support resolving dependencies with packages hosted on github. For example for python's setup tools, you can specify it in the setup.cfg:

install_requires =
    pyopenms
    mopepgen @ git+ssh://git@github.com/uclahs-cds/private-moPepGen.git

Conda's environment.yaml file also supports something like this, see here. So having a build system that can install dependencies from our internal repos will be really helpful. May also be beneficial for some of our R packages in the lab.

I think there are mainly two issues:

1. How to get docker build able to run ssh
2. How to let github action be able to run ssh

For 1, I have problem running it locally, because the docker image I'm building does not have the ssh key that is authorized by moPepGen. I saw people mentioning forwarding ssh using the --ssh argument but did not work yet. And I guess 2 is still blocking it even --ssh works.

@uclahs-cds/infrastructure

[nwiltsie]

Hey @zhuchcn, is this still an issue for you?