Support container-transports in --cache-to and --cache-from

[penn5]

Description There is no way to create a local cache without hosting a registry server on localhost and setting --cache-from/to=localhost/cache

Steps to reproduce the issue:

1. Set --cache-from=oci:/storage when using buildah build

Describe the results you received:

Error: unable to parse value provided `[]` to --cache-from: invalid repo "oci:/storage": must contain registry and repository: invalid reference format

Describe the results you expected: Buildah uses the provided path to cache images, allowing me to upload to CI cache coordinator.

Output of rpm -q buildah or apt list buildah:

buildah-1.30.0-1.fc38.x86_64

Output of buildah version:

Version:         1.30.0
Go Version:      go1.20.2
Image Spec:      1.0.2-dev
Runtime Spec:    1.1.0-rc.1
CNI Spec:        1.0.0
libcni Version:  v1.1.2
image Version:   5.25.0
Git Commit:      
Built:           Mon Apr 10 07:26:00 2023
OS/Arch:         linux/amd64
BuildPlatform:   linux/amd64

Output of cat /etc/*release:

NAME="Fedora Linux"
VERSION="38 (Container Image)"
ID=fedora
VERSION_ID=38
VERSION_CODENAME=""
PLATFORM_ID="platform:f38"
PRETTY_NAME="Fedora Linux 38 (Container Image)"
ANSI_COLOR="0;38;2;60;110;180"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:38"
DEFAULT_HOSTNAME="fedora"
HOME_URL="https://fedoraproject.org/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f38/system-administrators-guide/"
SUPPORT_URL="https://ask.fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=38
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=38
SUPPORT_END=2024-05-14
VARIANT="Container Image"
VARIANT_ID=container
Fedora release 38 (Thirty Eight)
Fedora release 38 (Thirty Eight)

Output of uname -a:

Linux c97c92126508 6.3.6-200.fc38.x86_64 #1 SMP PREEMPT_DYNAMIC Mon Jun  5 15:45:04 UTC 2023 x86_64 GNU/Linux

Output of cat /etc/containers/storage.conf: not relevant but if you really care i'm just using the buildah:latest image, podman run buildah cat /etc/containers/stroage.conf will do it

[flouthoc]

This is a nice feature request, I'll take it thanks.

[flouthoc]

Ouch, while this is a nice feature request. I think this will break public API. I am working on a PR here, lets see if we can have consensus on this https://github.com/containers/buildah/pull/4879

[penn5]

Why would it break public API? If it does, could always add another flag --new-caching=true to switch between modes...

[flouthoc]

@penn5 By public api i mean the publicly exposed type CacheFrom []reference.Named -> CacheFrom []types.ImageReference :)

[penn5]

Ah. I don't know Go, but my understanding is that there is not very much support for fancy types that could allow bypassing this. So either modifying the JSON deserializer to hackily deserialize as ImageReference, or making fields CacheFrom2 and CacheTo2. I would prefer the latter as the former still breaks the public API if we ever return these values, whereas with the latter we can just return a null CacheFrom and CacheTo meaning that consumers can parse the rest of the information without crashing, I hope.

[github-actions[bot]]

A friendly reminder that this issue had no activity for 30 days.

[rhatdan]

@penn5 @flouthoc anythong going on with this one?

[penn5]

Not at my end, I think flouthoc was gonna try to make a patch?

[flouthoc]

Yeah just waiting for @nalind and maintainers to take a look at this one https://github.com/containers/buildah/pull/4879

[github-actions[bot]]

A friendly reminder that this issue had no activity for 30 days.