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arXiv · 2309.00166

Charliecloud's layer-free, Git-based container build cache

Reid Priedhorsky·Jordan Ogas·Claude H.·Davis IV·Z. Noah Hounshel·Ashlyn Lee·Benjamin Stormer·R. Shane Goff
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Abstract

A popular approach to deploying scientific applications in high performance computing (HPC) is Linux containers, which package an application and all its dependencies as a single unit. This image is built by interpreting instructions in a machine-readable recipe, which is faster with a build cache that stores instruction results for re-use. The standard approach (used e.g. by Docker and Podman) is a many-layered union filesystem, encoding differences between layers as tar archives. Our experiments show this performs similarly to layered caches on both build time and disk usage, with a considerable advantage for many-instruction recipes. Our approach also has structural advantages: better diff format, lower cache overhead, and better file de-duplication. These results show that a Git-based cache for layer-free container implementations is not only possible but may outperform the layered approach on important dimensions.

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Reid Priedhorsky, Jordan Ogas, Claude H., Davis IV, Z. Noah Hounshel, Ashlyn Lee, Benjamin Stormer, R. Shane Goff. 2023-08-31. Charliecloud's layer-free, Git-based container build cache. https://arxiv.org/abs/2309.00166

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