Singularity Hub
What is Singularity Hub?
Singularity Hub is a registry for scientific images. The core of the Hub are the Singularity container images. A Singularity container image is built from a build file called Singularity, which is akin to the Dockerfile.
Building Images
You can interact with Singularity Hub via the interface, Github repositories, and the Singularity command line tool. The general workflow is as follows:
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create account on Singularity Hub, authentication with Github
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connect a Github repo to a new image. This means creating a webhook that will trigger a new build at each push to the repo.
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push the Singularity file to the repo to trigger the build
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Singularity-Hub will be notified of the push via the webhook, and the spec file will be version controlled via the Github commit. This repo url, commit id, storage location, and some secrets are then sent to Singularity Hub builders.
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the image is accessible programatically on Singularity Hub, and (soon) from the Singularity command line client.
Features
We will have more details coming in a manuscript, and for now please feel free to review the resources below, tell us about requests for features, or any questions that you might have.
Look Inside
After a build is complete, you can look through the folder/file hierarchy of your image, right in the web interface. You can also add containers to your "Container Snackbox" by clicking on various + buttons around the site. From the snackbox you can select one or a pair of images to compare.
A Container Collection
A container collection is associated with a Github repo, which will look for a file called Singularity in the base. Once a repo is connected to the hub, any new pushes will build a new image. Each image is version controlled with the commit, and you can define different tags for your images by pushing to different branches.
A Container Build
All build specs, logs, and running commands are easily viewable, and copy pastable directly from the Hub. This gives containers a (programmatic) transparency, so you know how they were built.
Reproducibility
Each build history, including the parameters for the cloud environment and builder, are stored, so you can go back and refer to any previous version. We will include more robust detail on this and all of the above in our upcoming manuscript.
Get Help
- Joining our Slack is the quickest way to talk to the developers and other users.
- Post an issue to this board for a question or issue about Singularity hub. If it pertains to a specific library image, please find the image, click on the Github link, and post to it's board.