chore(build-check): Add check script to verify that docker images use…

…d in registry are valid.

Signed-off-by: Sun Tan <sutan@redhat.com>

build/dockerfiles/Dockerfile

@@ -39,6 +39,7 @@ RUN ./check_metas_schema.sh v3
 RUN if [[ ${USE_DIGESTS} == "true" ]]; then ./write_image_digests.sh v3;fi
 RUN ./index.sh v3 > /build/v3/plugins/index.json
 RUN ./list_referenced_images.sh v3 > /build/v3/external_images.txt
+RUN ./check_referenced_images < /build/v3/external_images.txt
 RUN chmod -R g+rwX /build
 
 # Build registry, copying meta.yamls and index.json from builder

build/scripts/check_referenced_images.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+#
+# Copyright (c) 2019-2021 Red Hat, Inc.
+# This program and the accompanying materials are made
+# available under the terms of the Eclipse Public License 2.0
+# which is available at https://www.eclipse.org/legal/epl-2.0/
+#
+# SPDX-License-Identifier: EPL-2.0
+
+# Check with skopeo that images are valid. Image list should be passed through stdin.
+set -e
+
+while read extenal_image
+do  
+  echo "Checking that $extenal_image is a valid image";
+  skopeo inspect "docker://$extenal_image" >/dev/null;
+  echo "... OK";
+done