improve checking modprob netfilter (#6427)

pkg/minikube/command/kic_runner.go

@@ -115,13 +115,12 @@ func (k *kicRunner) RunCmd(cmd *exec.Cmd) (*RunResult, error) {
 		if elapsed > (1 * time.Second) {
 			glog.Infof("Done: %v: (%s)", oc.Args, elapsed)
 		}
-	} else {
-		if exitError, ok := err.(*exec.ExitError); ok {
-			rr.ExitCode = exitError.ExitCode()
-		}
-		err = fmt.Errorf("%s: %v\nstdout:\n%s\nstderr:\n%s", rr.Command(), err, rr.Stdout.String(), rr.Stderr.String())
+		return rr, nil
+	}
+	if exitError, ok := err.(*exec.ExitError); ok {
+		rr.ExitCode = exitError.ExitCode()
 	}
-	return rr, err
+	return rr, fmt.Errorf("%s: %v\nstdout:\n%s\nstderr:\n%s", rr.Command(), err, rr.Stdout.String(), rr.Stderr.String())
 
 }
 

pkg/minikube/cruntime/cruntime.go

@@ -167,11 +167,14 @@ func disableOthers(me Manager, cr CommandRunner) error {
 // enableIPForwarding configures IP forwarding, which is handled normally by Docker
 // Context: https://github.com/kubernetes/kubeadm/issues/1062
 func enableIPForwarding(cr CommandRunner) error {
-	c := exec.Command("sudo", "modprobe", "br_netfilter")
-	if _, err := cr.RunCmd(c); err != nil {
-		return errors.Wrap(err, "br_netfilter")
+	c := exec.Command("sudo", "sysctl", "net.netfilter.nf_conntrack_count")
+	if rr, err := cr.RunCmd(c); err != nil {
+		glog.Infof("couldn't verify netfilter by %q which might be okay. error: %v", rr.Command(), err)
+		c = exec.Command("sudo", "modprobe", "br_netfilter")
+		if _, err := cr.RunCmd(c); err != nil {
+			return errors.Wrapf(err, "br_netfilter")
+		}
 	}
-
 	c = exec.Command("sudo", "sh", "-c", "echo 1 > /proc/sys/net/ipv4/ip_forward")
 	if _, err := cr.RunCmd(c); err != nil {
 		return errors.Wrapf(err, "ip_forward")