buildah bud --from with absolute path to oci-archive fails

[angelcerveraroldan]

Issue Description

After upgrading to the latest version of podman and its dependencies (podman 6.0.0-rc1, buildah 1.44.0), we noticed failures in some of our tests that were using Containerfiles in the following form:

FROM oci-archive:/absolute-path

It seems that using absolute paths like this is no longer supported since path sanitation was introduced in #5975. This makes sense for Containefile FROM directives, however the same failures also occur when using absolute paths with podman build or buildah bud:

podman build --from oci-archive:<absolute-path>
buildah bud --from oci-archive:<absolute-path>

When using --from on the command line, the user is explicitly providing the path, and there is no expectation that the build is self containing, so I expected the last command to work.

The error message itself (attached in the reproduction steps) is not super self explanatory, I believe what is happening is that the provided absolute path is being resolved as a relative path to the build context directory, leading to failures.

Please let me know if you need any more details!

Steps to reproduce the issue

[core@cosa-devsh ~]$ buildah --version
buildah version 1.44.0 (image-spec 1.1.1, runtime-spec 1.3.0)

[core@cosa-devsh ~]$ skopeo copy docker://quay.io/fedora/fedora-minimal:latest oci-archive:/tmp/fedora.ociarchive
Getting image source signatures
Copying blob fb1251ea7033 done   | 
Copying config 8d41eb7fb8 done   | 
Writing manifest to image destination

[core@cosa-devsh ~]$ cat > /tmp/Containerfile <<'EOF'
FROM overridden
RUN touch /etc/foo
EOF

[core@cosa-devsh ~]$ buildah bud --from oci-archive:/tmp/fedora.ociarchive -f /tmp/Containerfile
WARN[0000] expected to have archived a copy of "/tmp/fedora.ociarchive", missed it 
STEP 1/2: FROM oci-archive:/tmp/fedora.ociarchive
Error: creating build container: loading index: open /var/tmp/container_images_oci48477806/index.json: no such file or directory

Describe the results you received

Could not run podman build --from / buildah bud --from with absolute paths.

Describe the results you expected

To be able to run podman build --from / buildah bud --from with absolute paths.

buildah version output

[core@cosa-devsh ~]$ buildah --version
buildah version 1.44.0 (image-spec 1.1.1, runtime-spec 1.3.0)

buildah info output

{
    "host": {
        "Distribution": {
            "distribution": "fedora",
            "version": "45"
        },
        "MemFree": 105451520,
        "MemTotal": 989708288,
        "OCIRuntime": "crun",
        "SwapFree": 0,
        "SwapTotal": 0,
        "arch": "amd64",
        "cpus": 12,
        "hostname": "cosa-devsh",
        "kernel": "7.2.0-0.rc0.260622gef0c9f75a195.6.fc45.x86_64",
        "os": "linux",
        "rootless": true,
        "uptime": "7m 46.15s",
        "variant": ""
    },
    "store": {
        "ContainerStore": {
            "number": 1
        },
        "GraphDriverName": "overlay",
        "GraphImageStore": "",
        "GraphOptions": [
            "overlay.mountopt=nodev,metacopy=on"
        ],
        "GraphRoot": "/var/home/core/.local/share/containers/storage",
        "GraphStatus": {
            "Backing Filesystem": "xfs",
            "Native Overlay Diff": "false",
            "Supports d_type": "true",
            "Supports shifting": "false",
            "Supports volatile": "true",
            "Using metacopy": "false"
        },
        "GraphTransientStore": false,
        "ImageStore": {
            "number": 2
        },
        "RunRoot": "/run/user/1000/containers"
    }
}

Provide your storage.conf

[core@cosa-devsh ~]$ cat /usr/share/containers/storage.conf
# This file is the configuration file for all tools
# that use the containers/storage library. The storage.conf file
# overrides all other storage.conf files. Container engines using the
# container/storage library do not inherit fields from other storage.conf
# files.
#
# See man 5 containers-storage.conf for more information
# The "storage" table contains all of the server options.
[storage]

[storage.options]

[storage.options.pull_options]

[storage.options.overlay]
mountopt = "nodev"

[storage.options.vfs]

[core@cosa-devsh ~]$ cat /etc/containers/storage.conf
cat: /etc/containers/storage.conf: No such file or directory

Upstream Latest Release

Yes

Additional environment details

The above commands were run using a Fedora CoreOS 45 rawhide qcow2 image in QEMU.

Additional information

No response