Hello Guix, Two years ago, i released nix2container [1], a Go library and binary to build container images from Nix expressions. However, this Go code is not tightly coupled with Nix and has been designed to potentially work with Guix [2]!
nix2container offers the following main features: - It uses a layering algorithm to group storepaths into layers [3] - It avoids writing an image tarball in your Guix store (reduce IOs and storage) Basically, to build a container image, nix2container relies on two steps: 1. The nix2container Go binary takes the reference graph [4] of the container image closure to generates a JSON file describing the image configuration and the layers. 2. This JSON file can then be consumed by a patched Skopeo version[5] to build or push an image [8]. In case you would like to try nix2container with Guix, in theory, you would need to add the support of another input reference graph format [6] and a write simple Guix derivations [7] calling the nix2container binary. Hoping it could be useful, lewo. [1] https://github.com/nlewo/nix2container [2] https://github.com/nlewo/containers-image-nix/blob/e342762cf7274dd7449343f3488723898da63f00/nix/utils.go#L55 [3] https://grahamc.com/blog/nix-and-layered-docker-images/ [4] https://nixos.org/manual/nix/stable/language/advanced-attributes.html?highlight=exportReferencesGraph#adv-attr-exportReferencesGraph [5] https://github.com/nlewo/containers-image-nix/blob/9d7f33ef0058f4df4c0912025f43c758a3289d76/default.nix#L31 [6] https://github.com/nlewo/containers-image-nix/blob/9d7f33ef0058f4df4c0912025f43c758a3289d76/data/closure-graph.json#L1 [7] https://github.com/nlewo/containers-image-nix/blob/9d7f33ef0058f4df4c0912025f43c758a3289d76/default.nix#L305 [8] https://github.com/nlewo/containers-image-nix/blob/9d7f33ef0058f4df4c0912025f43c758a3289d76/default.nix#L47
