scripts/build-image: use libosinfo to detect installer

When using virt-install --location disk.iso the libosinfo library is
used to detect operating system and path to kernel and initramdisk on
the ISO image. This is done by comparing disk label against its database
of known OSes.

While most of the images I tested do work, to fully ensure this is the
case and to prevent regressions, let's run this tool after image is
built in case it is an ISO.

For unknown OS versions, the database contains "unknown" entries which
are still recognized as unreleased versions, so this should work even if
our runners will have older version of the library.

Author: lzap

test/scripts/build-image

@@ -2,6 +2,7 @@
 import argparse
 import json
 import os
+import sys
 
 import imgtestlib as testlib
 
@@ -64,6 +65,19 @@ def main():
     }
     testlib.write_build_info(build_dir, build_info)
 
+    # Test ISO installer with libosinfo to ensure that virt-install can locate embedded
+    # kernel and initrd for direct boot.
+    image_path = testlib.find_image_file(build_dir)
+    print(f"🔍 Testing ISO installer with libosinfo: {image_path}")
+    if image_path.endswith('.iso'):
+        stdout, stderr = testlib.runcmd(["osinfo-detect", image_path])
+        output = stdout.decode() + stderr.decode()
+
+        if "Media is an installer" not in output:
+            print("❌ osinfo-detect output does not detect the image as a valid installer:")
+            print(output)
+            sys.exit(1)
+
 
 if __name__ == "__main__":
     main()

test/scripts/install-dependencies

@@ -8,6 +8,8 @@ dnf -y install \
     btrfs-progs-devel \
     cloud-utils \
     device-mapper-devel \
+    libosinfo \
+    gettext \
     libvirt-devel \
     gcc \
     go \
@@ -32,3 +34,16 @@ dnf install -y lorax
 # we need this for the qemu boot tests and for any python tests but
 # could skip it for other testing.
 pip install .
+
+# latest database for libosinfo-detect checks
+OSDB_DIR=$(mktemp -d -t osinfodb.XXXXXX)/osinfo-db
+cleanup() {
+	test "$OSDB_DIR" && rm -rf "$OSDB_DIR"
+}
+trap cleanup EXIT INT TERM
+
+git clone https://gitlab.com/libosinfo/osinfo-db "$OSDB_DIR"
+pushd "$OSDB_DIR"
+# install into $HOME/.config/osinfo
+make install -j2
+popd