tests/content-origins: Verify expected vendor for all RPM packages

As we move to support multiple streams (particularly for C9S versus RHEL)
we should ensure that we're not accidentally including content
from CentOS in official RHEL builds, and vice versa.  The RPM vendor
field is useful for this.

For now, this test just verifies Fedora and RHEL vendors, and I
tested on both.

tests/kola/content-origins/data/commonlib.sh

@@ -0,0 +1 @@
+../../data/commonlib.sh

tests/kola/content-origins/test.sh

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+#!/bin/bash
+# kola: {"platforms": "qemu", "exclusive": false, "distros": "fcos rhcos" }
+# Verify the RPM %{vendor} flag for everything installed matches what we expect.
+#
+# - platforms: qemu
+#   - This test should pass everywhere if it passes anywhere.
+# - distros: This only handles Fedora and RHEL today.
+
+set -xeuo pipefail
+
+. $KOLA_EXT_DATA/commonlib.sh
+
+. /usr/lib/os-release
+
+case "${ID}" in
+    fedora) vendor='Fedora Project';;
+    rhel|rhcos) vendor='Red Hat, Inc.';;
+    *) echo "Unknown operating system ID=${ID}; skipping this test"; exit 0;;
+esac
+
+cd $(mktemp -d)
+rpm -qa --queryformat='%{name},%{vendor}\n' > rpmvendors.txt
+if grep -vF ",${vendor}" rpmvendors.txt > unmatched.txt; then
+    cat unmatched.txt
+    fatal "Expected only vendor ${vendor} for all packages"
+fi
+echo "ok all RPMs produced by Vendor: ${vendor}"
+