This commit adds support for swapping out the compression algorithm
used in all major docker-tools commands that generate images. The
default algorithm remains unchanged (gzip).
After #268458, when setting `enableFakechroot = true` and
`includeStorePaths = false`, some of the store paths were getting
included into the image anyway, thru `bind-paths`.
This resulted in unexpectedly large images.
Now, the images will not contain any store paths under those
circumstances.
For https://github.com/NixOS/nixpkgs/pull/125211 I tried to test
the fetcher with
nix-build -A dockerTools.examples.nixFromDockerHub --option substitute false
But it failed. I haven't figured out the cause, but the outputs
match, so it's probably the hashing method (flat/recursive) that
changed at some point. (The names did match.)
Adds includeStorePaths, allowing the omission of the store paths.
You generally want to leave it on, but tooling may disable this
to insert the store paths more efficiently via other means, such
as bind mounting the host store.
It is now possible to pass a `fromImage` to `buildLayeredImage` and
`streamLayeredImage`, similar to what `buildImage` currently supports.
This will prepend the layers of the given base image to the resulting
image, while ensuring that at most `maxLayers` are used. It will also
ensure that environment variables from the base image are propagated
to the final image.
When using `buildLayeredImage`, it is not possible to specify an image
name of the form `<registry>/my/image`, although it is a valid name.
This is due to derivations under `buildLayeredImage` using that image
name as their derivation name, but slashes are not permitted in that
context.
A while ago, #13099 fixed that exact same problem in `buildImage` by
using `baseNameOf name` in derivation names instead of `name`. This
change does the same thing for `buildLayeredImage`.
This provides a /etc/passwd and /etc/group that contain root and nobody.
Useful when packaging binaries that insist on using nss to look up
username/groups (like nginx).
The current nginx example used the `runAsRoot` parameter to setup
/etc/group and /etc/passwd (which also doesn't exist in
buildLayeredImage), so we can now just use fakeNss there and use
buildLayeredImage.
The image tag can be specified or generated from the output hash.
Previously, a generated tag could be recovered from the evaluated
image with some string operations.
However, with the introduction of streamLayeredImage, it's not
feasible to compute the generated tag yourself.
With this change, the imageTag attribute is set unconditionally,
for the buildImage, buildLayeredImage, streamLayeredImage functions.
