labels for Singularity (scientific containers)

[vsoch]

hey label-schema team! I'm one of the developers for Singularity (http://singularity.lbl.gov) which is a container that is primarily for HPC and science (doesn't have security risks of Docker). I've seen your schema used for some Docker containers, and would be interested to follow suit for Singularity. Right now our default metadata labels are rather general:

singularity inspect --json centos-7.img
{
    "data": {
        "attributes": {
            "labels": {
                "build-date": "20170605",
                "vendor": "CentOS",
                "name": "CentOS Base Image",
                "license": "GPLv2"
            }
        },
        "type": "container"
    }
}

the above outputs the JSON API spec, but the labels itself is just a flat dictionary:

singularity inspect centos-7.img
 {
    "build-date": "20170605",
    "vendor": "CentOS",
    "name": "CentOS Base Image",
    "license": "GPLv2"
}

We are adding modular application support for inside the images, and in addition to a structural format, since we will have labels for each internal module (and the container) it would be really great to have standard labels! This might also help issue #31. What are your thoughts? What is the process we could go about this? What I would propose to do is make a first pass at a set of singularity labels here --> https://docs.google.com/document/d/1k0I1M1BIR1aqGxVVJrow_Gj3T8BXHco-oqnreYKuxL8/edit?usp=sharing (this is the document we are working on the internal structure) and then if you like, I can PR something here? Do you have a spec / definitions outside of this repo?

Generally, scientists need more information about container metrics that are important for reproducibility. This would mean things like software versioning and hardware intended for, some metadata about the authors possibly, and labels specific to the modules inside (and this is a hard territory to venture into, but also workflow type things like inputs and outputs). The goal would be to find a container, know how it was made, what it is intended for and how to run it,and then be able to do so.

Looking forward to chatting with you!

[vsoch]

hi label schema!

We have a PR under way ( apptainer/singularity#843 apptainer/singularity#831) to add labels per the first specification using label-schema, specifically a bootstrap image looks like this:

 singularity inspect dino.img
{
    "org.label-schema.usage.singularity.deffile.bootstrap": "docker",
    "MAINTAINER": "Vanessasaurus",
    "org.label-schema.usage.singularity.deffile": "Singularity.help",
    "org.label-schema.usage": "/.singularity.d/runscript.help",
    "org.label-schema.schema-version": "1.0",
    "org.label-schema.usage.singularity.deffile.from": "ubuntu:latest",
    "org.label-schema.build-date": "2017-07-28T21:57:15-04:00",
    "org.label-schema.usage.singularity.runscript.help": "/.singularity.d/runscript.help",
    "org.label-schema.usage.singularity.version": "2.3.1-add/label-schema.gefbf35f"
}

Does that look reasonable, or do you have suggestions for improvement? And the final question before we merge is if there anywhere / anything we need to do in order to document usage in our containers. This will be merged into development branch, and go out with release of 2.4. Thanks!

[vsoch]

Is this repository being maintained? I posted this issue summer of last year, and no one has responded... we are wanting to add an imagetype label and it would really be helpful if someone that maintains the specification could give some basic guidance. Thank you!

apptainer/singularity#1268

[lizrice]

Hi @vsoch, the label schema work is now part of the OCI: https://github.com/opencontainers/image-spec