build: Add image version label to test container image

Set org.opencontainers.image.version in the Dockerfile so that
bootc status shows a Version line for the booted deployment.
The version is derived from git by the Justfile and defaults
to "devel" for standalone builds.

Assisted-by: OpenCode (Claude claude-opus-4-6)
Signed-off-by: Colin Walters <walters@verbum.org>

Author: cgwalters

Dockerfile

@@ -67,6 +67,9 @@ LABEL bootc.testimage="1"
 # Otherwise standard metadata
 LABEL containers.bootc 1
 LABEL ostree.bootable 1
+# Version from git, passed via Justfile; ensures `bootc status` shows a version
+ARG image_version="devel"
+LABEL org.opencontainers.image.version="${image_version}"
 # https://pagure.io/fedora-kiwi-descriptions/pull-request/52
 ENV container=oci
 # Optional labels that only apply when running this image as a container. These keep the default entry point running under systemd.

Justfile

@@ -69,7 +69,8 @@ build: package _keygen && _pull-lbi-images
     set -xeuo pipefail
     test -d target/packages
     pkg_path=$(realpath target/packages)
-    podman build {{_nocache_arg}} --build-context "packages=${pkg_path}" -t {{base_img}} {{buildargs}} .
+    eval $(just _git-build-vars)
+    podman build {{_nocache_arg}} --build-arg=image_version=${VERSION} --build-context "packages=${pkg_path}" -t {{base_img}} {{buildargs}} .
 
 # Show available build variants and current configuration
 [group('core')]