tests: add image check before running coco tests

Currently, there are some issues with pulling images in CI, such as :
https://github.com/kata-containers/kata-containers/actions/runs/10109747602/job/27959198585

This issue is caused by switching between different snapshotters for the same image in some scenarios.
To resolve it, we can check existing images to ensure all content is available locally before running tests.

Fixes: #10029

Signed-off-by: ChengyuZhu6 <chengyu.zhu@intel.com>

tests/integration/kubernetes/gha-run.sh

@@ -493,6 +493,22 @@ function cleanup_snapshotter() {
 	echo "::endgroup::"
 }
 
+# Check existing images to ensure all content is available locally before running tests
+function image_check() {
+	local ctr_args="sudo ctr "
+	if [[ " k3s rke2 " =~ " ${KUBERNETES} " ]]; then
+		ctr_args+="--address /run/k3s/containerd/containerd.sock "
+	fi
+	ctr_args+="--namespace k8s.io "
+	local incomplete_images=$($ctr_args image check | grep "incomplete" | awk '{print $1}')
+	if [ -z "$incomplete_images" ]; then
+		return
+	fi
+	for incomplete_image in $incomplete_images; do
+		$ctr_args content fetch $incomplete_image || true
+	done
+}
+
 function deploy_nydus_snapshotter() {
 	echo "::group::deploy_nydus_snapshotter"
 	ensure_yq
@@ -556,6 +572,10 @@ function deploy_nydus_snapshotter() {
 	echo "::group::nydus snapshotter describe"
 	kubectl_retry describe pod --selector=app=nydus-snapshotter -n nydus-system
 	echo "::endgroup::"
+
+	echo "::group::image check"
+	image_check
+	echo "::endgroup::"
 }
 
 function cleanup_nydus_snapshotter() {