This is useful for a use-case we have with a Nix-based CI system that
specifies things like deploy steps as passthru attributes[0].
Previously the only way to do this would have been to concatenate
attributes onto the resulting derivation, but passing them in and
actually treating them as proper passthru attributes is cleaner.
[0]: https://cs.tvl.fyi/depot@f7d7da6aceb407b719cf4683a75878fd3aca319e/-/blob/nix/buildkite/default.nix?L222-226
Apparently, a non-existent nsswitch.conf causes a very misleading host
resolution, differing from the defaults people are used to.
According to
https://github.com/golang/go/issues/22846#issuecomment-346377144, glibc
says the default is "dns [!UNAVAIL=return] files".
This means, `/etc/hosts` isn't really honored, causing all sorts of
unexpected behaviour.
Let's prevent this, and first ask `/etc/hosts` before querying DNS, like
we do on NixOS too.
skopeo 1.4.x doesn't accept --src-tls-verify as a flag to the *program*,
only as a flag to copy; we must pass it after the "copy" verb, or it
will fail with:
> FATA[0000] unknown flag: --src-tls-verify
skopeo will disable the progress bar if it detects that stdout isn't a
TTY - in order to make it think that stdout _isn't_ a TTY and therefore
avoid it printing a lot of "…" on separate lines, we pipe the output
through cat.
This changes the output from:
…
…
…
…
…
…
to the eminently more useful and less spammy:
Getting image source signatures
Copying blob sha256:[snip]
Copying blob sha256:[snip]
Copying blob sha256:[snip]
Copying config sha256:[snip]
Writing manifest to image destination
Storing signatures
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.
The `docker load` command supports loading tarballs that contain
multiple docker images with their respective image names and tags. This
enables distributing these images as a single file which simplifies the
release of software when an application requires multiple services to
run.
However, pkgs.dockerTools only create tarballs with a single docker
image and there exists is no mechanism in nixpkgs to combine the created
tarballs. This commit implements merging of tarballs in a way that is
compatible with `docker load`.
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`.
`stream_layered_image.py` currently assumes that the store root will be
at `/nix/store`, although the user might have configured this
differently. This makes `buildLayeredImage` unusable with stores having
a different root, as they will fail an assertion in the python script.
This change updates that assertion to use `builtins.storeDir` as the
source of truth about where the store lives, instead of assuming
`/nix/store`.
Warning about future breaking changes is wrong.
- It suggests that the maintainers don't value backwards compatibility.
They do.
- It implies that other parts of Nixpkgs won't ever break. They will.
- It implies that a well-defined "public" interface exists. It doesn't.
- If the reasons above didn't apply, it should have been in the manual
instead.
Breaking changes will come, especially to the interface. That can be the
only way we can make progress without breaking the image _contents_.
I don't think dockerTools is any different from most of Nixpkgs in
these regards.
