e2e: use error wrapping with %w

The recently introduced failure handling in ExpectNoError depends on error
wrapping: if an error prefix gets added with `fmt.Errorf("foo: %v", err)`, then
ExpectNoError cannot detect that the root cause is an assertion failure and
then will add another useless "unexpected error" prefix and will not dump the
additional failure information (currently the backtrace inside the E2E
framework).

Instead of manually deciding on a case-by-case basis where %w is needed, all
error wrapping was updated automatically with

    sed -i "s/fmt.Errorf\(.*\): '*\(%s\|%v\)'*\",\(.* err)\)/fmt.Errorf\1: %w\",\3/" $(git grep -l 'fmt.Errorf' test/e2e*)

This may be unnecessary in some cases, but it's not wrong.

test/e2e/kubectl/kubectl.go

@@ -1382,7 +1382,7 @@ metadata:
 			err := wait.PollImmediate(time.Second, time.Minute, func() (bool, error) {
 				cj, err := c.BatchV1().CronJobs(ns).List(ctx, metav1.ListOptions{})
 				if err != nil {
-					return false, fmt.Errorf("Failed getting CronJob %s: %v", ns, err)
+					return false, fmt.Errorf("Failed getting CronJob %s: %w", ns, err)
 				}
 				return len(cj.Items) > 0, nil
 			})
@@ -2026,11 +2026,11 @@ func checkContainersImage(containers []v1.Container, expectImage string) bool {
 func getAPIVersions(apiEndpoint string) (*metav1.APIVersions, error) {
 	body, err := curl(apiEndpoint)
 	if err != nil {
-		return nil, fmt.Errorf("Failed http.Get of %s: %v", apiEndpoint, err)
+		return nil, fmt.Errorf("Failed http.Get of %s: %w", apiEndpoint, err)
 	}
 	var apiVersions metav1.APIVersions
 	if err := json.Unmarshal([]byte(body), &apiVersions); err != nil {
-		return nil, fmt.Errorf("Failed to parse /api output %s: %v", body, err)
+		return nil, fmt.Errorf("Failed to parse /api output %s: %w", body, err)
 	}
 	return &apiVersions, nil
 }
@@ -2048,7 +2048,7 @@ func startProxyServer(ns string) (int, *exec.Cmd, error) {
 	buf := make([]byte, 128)
 	var n int
 	if n, err = stdout.Read(buf); err != nil {
-		return -1, cmd, fmt.Errorf("Failed to read from kubectl proxy stdout: %v", err)
+		return -1, cmd, fmt.Errorf("Failed to read from kubectl proxy stdout: %w", err)
 	}
 	output := string(buf[:n])
 	match := proxyRegexp.FindStringSubmatch(output)
@@ -2266,17 +2266,17 @@ func newBlockingReader(s string) (io.Reader, io.Closer, error) {
 func createApplyCustomResource(resource, namespace, name string, crd *crd.TestCrd) error {
 	ginkgo.By("successfully create CR")
 	if _, err := e2ekubectl.RunKubectlInput(namespace, resource, "create", "--validate=true", "-f", "-"); err != nil {
-		return fmt.Errorf("failed to create CR %s in namespace %s: %v", resource, namespace, err)
+		return fmt.Errorf("failed to create CR %s in namespace %s: %w", resource, namespace, err)
 	}
 	if _, err := e2ekubectl.RunKubectl(namespace, "delete", crd.Crd.Spec.Names.Plural, name); err != nil {
-		return fmt.Errorf("failed to delete CR %s: %v", name, err)
+		return fmt.Errorf("failed to delete CR %s: %w", name, err)
 	}
 	ginkgo.By("successfully apply CR")
 	if _, err := e2ekubectl.RunKubectlInput(namespace, resource, "apply", "--validate=true", "-f", "-"); err != nil {
-		return fmt.Errorf("failed to apply CR %s in namespace %s: %v", resource, namespace, err)
+		return fmt.Errorf("failed to apply CR %s in namespace %s: %w", resource, namespace, err)
 	}
 	if _, err := e2ekubectl.RunKubectl(namespace, "delete", crd.Crd.Spec.Names.Plural, name); err != nil {
-		return fmt.Errorf("failed to delete CR %s: %v", name, err)
+		return fmt.Errorf("failed to delete CR %s: %w", name, err)
 	}
 	return nil
 }

test/e2e/kubectl/portforward.go

@@ -389,7 +389,7 @@ func doTestOverWebSockets(ctx context.Context, bindAddress string, f *framework.
 	gomega.Eventually(ctx, func() error {
 		channel, msg, err := wsRead(ws)
 		if err != nil {
-			return fmt.Errorf("failed to read completely from websocket %s: %v", url.String(), err)
+			return fmt.Errorf("failed to read completely from websocket %s: %w", url.String(), err)
 		}
 		if channel != 0 {
 			return fmt.Errorf("got message from server that didn't start with channel 0 (data): %v", msg)
@@ -403,7 +403,7 @@ func doTestOverWebSockets(ctx context.Context, bindAddress string, f *framework.
 	gomega.Eventually(ctx, func() error {
 		channel, msg, err := wsRead(ws)
 		if err != nil {
-			return fmt.Errorf("failed to read completely from websocket %s: %v", url.String(), err)
+			return fmt.Errorf("failed to read completely from websocket %s: %w", url.String(), err)
 		}
 		if channel != 1 {
 			return fmt.Errorf("got message from server that didn't start with channel 1 (error): %v", msg)
@@ -426,7 +426,7 @@ func doTestOverWebSockets(ctx context.Context, bindAddress string, f *framework.
 	gomega.Eventually(ctx, func() error {
 		channel, msg, err := wsRead(ws)
 		if err != nil {
-			return fmt.Errorf("failed to read completely from websocket %s: %v", url.String(), err)
+			return fmt.Errorf("failed to read completely from websocket %s: %w", url.String(), err)
 		}
 		if channel != 0 {
 			return fmt.Errorf("got message from server that didn't start with channel 0 (data): %v", msg)