test/e2e_kubeadm: add URL scheme test for node CRI annotations

The tests in nodes_test.go check if the Node objects
in a kubeadm cluster are annotated with a CRI socket
path. It is used by kubeadm to store a CRI socket per node.

Add a new test condition to verify if the CRI socket path
is prefixed with URL scheme "unix://".

test/e2e_kubeadm/nodes_test.go

@@ -18,6 +18,7 @@ package kubeadm
 
 import (
 	"context"
+
 	rbacv1 "k8s.io/api/rbac/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/test/e2e/framework"
@@ -51,9 +52,11 @@ var _ = Describe("nodes", func() {
 			List(context.TODO(), metav1.ListOptions{})
 		framework.ExpectNoError(err, "error reading nodes")
 
-		// checks that the nodes have the CRI annotation
+		// Checks that the nodes have the CRI socket annotation
+		// and that it is prefixed with a URL scheme
 		for _, node := range nodes.Items {
 			gomega.Expect(node.Annotations).To(gomega.HaveKey(nodesCRISocketAnnotation))
+			gomega.Expect(node.Annotations[nodesCRISocketAnnotation]).To(gomega.HavePrefix("unix://"))
 		}
 	})