ART: Use rpm-ostree --repo with YUM_REPO_NAMES for extensions

Similar to the node image build (PR openshift#1935), modify the extensions build
to use --repo="${YUM_REPO_NAMES}" instead of relying on hardcoded repo
names in the extensions yaml files.

Changes:
- extensions/Containerfile: Add YUM_REPO_NAMES build arg
- extensions/build.sh: Mount repos, strip repos: sections from yaml,
  use --repo flag with rpm-ostree compose extensions
- extensions/build-args-*.conf: Define YUM_REPO_NAMES for each RHEL version

This allows ART to inject the correct repo names (e.g., rhel-9-baseos-rpms)
instead of the extensions yaml files using version-specific names
(e.g., rhel-9.8-baseos) that don't match what ART provides.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

rh-pre-commit.version: 2.4.0
rh-pre-commit.check-secrets: ENABLED

Author: locriandev

extensions/Containerfile

@@ -6,6 +6,7 @@ WORKDIR /os
 ADD . .
 ARG OPENSHIFT_CI=0
 ARG OPENSHIFT_VERSION=overridden
+ARG YUM_REPO_NAMES=overridden
 RUN --mount=type=secret,id=yumrepos,target=/os/secret.repo extensions/build.sh
 
 ## Creates the repo metadata for the extensions.

extensions/build-args-10.2-5.0.conf

@@ -0,0 +1,4 @@
+OPENSHIFT_VERSION=5.0
+
+# The names of the yum repos to use for the extensions build.
+YUM_REPO_NAMES=rhel-10.2-baseos,rhel-10.2-appstream,rhel-10.2-fast-datapath,rhel-10.2-server-ose-5.0

extensions/build-args-9.8-5.0.conf

@@ -0,0 +1,4 @@
+OPENSHIFT_VERSION=5.0
+
+# The names of the yum repos to use for the extensions build.
+YUM_REPO_NAMES=rhel-9.8-baseos,rhel-9.8-appstream,rhel-9.8-fast-datapath,rhel-9.8-server-ose-5.0,rhel-9.8-nfv,rhel-9.8-highavailability

extensions/build.sh

@@ -6,16 +6,41 @@ if [ "${OPENSHIFT_CI}" != 0 ]; then
     ci/get-ocp-repo.sh ocp.repo
 fi
 
+# add all the repos from the current directory (including mounted in secret.repo)
+# into `/etc/yum.repos.d` so dnf sees them
+cat /os/*.repo >> /etc/yum.repos.d/git.repo
+
 # just to parse the treefile, rpm-ostree still wants to read referenced "externals" (e.g. passwd, group)
 # hack around this for now by deleting the problematic bits; we should tweak rpm-ostree instead
 jq 'del(.["check-passwd","check-groups"])' /usr/share/rpm-ostree/treefile.json > filtered.json
 
-
 . /etc/os-release
 extensions_yaml="extensions/${ID}-${VERSION_ID}.yaml"
 # Replace the __OCP_VERSION__ placeholder with the actual OpenShift version.
 # This allows the same YAML file to be used across different OCP versions
 # (e.g. 4.23 and 5.0) without duplication.
 sed -i "s/__OCP_VERSION__/${OPENSHIFT_VERSION}/g" "$extensions_yaml"
+
+# Strip out any repos: sections from the extensions yaml file since we'll
+# use --repo instead to specify repos explicitly via YUM_REPO_NAMES
+python3 <<EOF
+import yaml
+
+with open('$extensions_yaml', 'r') as fh:
+    d = yaml.safe_load(fh)
+
+# Remove top-level repos section
+d.pop('repos', None)
+
+# Remove repos sections from individual extensions
+for ext in d.get('extensions', {}).values():
+    if isinstance(ext, dict):
+        ext.pop('repos', None)
+
+with open('$extensions_yaml', 'w') as fh:
+    yaml.dump(d, fh, default_flow_style=False)
+EOF
+
 rpm-ostree compose extensions filtered.json "$extensions_yaml" \
+    --repo="${YUM_REPO_NAMES}" \
     --rootfs=/ --output-dir=/usr/share/rpm-ostree/extensions/