Merge pull request #10042 from spowelljr/snapFix

Fix docker driver cert copy on ubuntu's snap package manager

pkg/minikube/command/kic_runner.go

@@ -24,6 +24,7 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"path/filepath"
 	"runtime"
 	"strconv"
 	"strings"
@@ -185,7 +186,18 @@ func (k *kicRunner) Copy(f assets.CopyableFile) error {
 		}
 	}
 	klog.Infof("%s (temp): %s --> %s (%d bytes)", k.ociBin, src, dst, f.GetLength())
-	tf, err := ioutil.TempFile("", "tmpf-memory-asset")
+	tmpFolder := ""
+
+	// Snap only allows an application to see its own files in /tmp, making Docker unable to copy memory assets
+	// https://github.com/kubernetes/minikube/issues/10020
+	if isSnapBinary() {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return errors.Wrap(err, "detecting home dir")
+		}
+		tmpFolder = os.Getenv(home)
+	}
+	tf, err := ioutil.TempFile(tmpFolder, "tmpf-memory-asset")
 	if err != nil {
 		return errors.Wrap(err, "creating temporary file")
 	}
@@ -197,6 +209,15 @@ func (k *kicRunner) Copy(f assets.CopyableFile) error {
 	return k.copy(tf.Name(), dst)
 }
 
+func isSnapBinary() bool {
+	ex, err := os.Executable()
+	if err != nil {
+		return false
+	}
+	exPath := filepath.Dir(ex)
+	return strings.Contains(exPath, "snap")
+}
+
 func (k *kicRunner) copy(src string, dst string) error {
 	fullDest := fmt.Sprintf("%s:%s", k.nameOrID, dst)
 	if k.ociBin == oci.Podman {