ncar-xdev / repo2apptainer Goto Github PK

Currrently, repo2singularity relies on repo2docker to create a docker image that repo2singularity converts into a singularity image file (SIF). I was thinking that we could use the output of repo2docker --no-build to generate a singularity definition file. This would allows us to bypass the intermediary step of creating a docker image.

• step 1: Generate Dockerfile

$ jupyter-repo2docker --no-build --debug --ref 9ced85dd9a84859d0767369e58f33912a214a3cf https://github.com/norvig/pytudes 2> dockerfile.tmp
$ sed -n -e '/FROM/,$p' dockerfile.tmp > Dockerfile

• Step 2: Convert Dockerfile into SIF using spython tool

$ spython recipe Dockerfile >> Singularity

• Step 3: Build the singularity container locally (if the user has sudo permissions)

$ sudo singularity build myimage.sif Singularity

Or build the singularity container on a remote builder (https://cloud.sylabs.io/builder) (does not require sudo)

singularity --remote build myimage.sif Singularity

Unfortunately, as it is pointed out in the documentation, this output is present for debugging purposes only :(. There are things that are hard coded because they are being copied from the local environment. So, this option of bypassing docker images seems to be out of scope for repo2singularity. I am just opening this issue for future reference.

Xref:

• Repo2Docker: make it easy to start from arbitrary docker image

• jupyterhub/repo2docker#202

This is an awesome project!

Recently, @manics has done a lot of work in allowing alternative backends to repo2docker. https://github.com/manics/repo2podman is the canonical second implementation, using podman. Would love for this to also use that interface, and fix issues we need to upstream.