Allow loading image from standard input stream

Author: afbjorklund

cmd/minikube/cmd/image.go

@@ -17,6 +17,8 @@ limitations under the License.
 package cmd
 
 import (
+	"io"
+	"io/ioutil"
 	"os"
 	"strings"
 
@@ -40,6 +42,22 @@ var (
 	imgRemote bool
 )
 
+func saveFile(r io.Reader) (string, error) {
+        tmp, err := ioutil.TempFile("", "build.*.tar")
+        if err != nil {
+                return "", err
+        }
+        _, err = io.Copy(tmp, r)
+        if err != nil {
+                return "", err
+        }
+        err = tmp.Close()
+        if err != nil {
+                return "", err
+        }
+        return tmp.Name(), nil
+}
+
 // loadImageCmd represents the image load command
 var loadImageCmd = &cobra.Command{
 	Use:     "load",
@@ -61,7 +79,11 @@ var loadImageCmd = &cobra.Command{
 			local = false
 		} else {
 			for _, img := range args {
-				if strings.HasPrefix(img, "/") || strings.HasPrefix(img, ".") {
+				if img == "-" { // stdin
+					local = true
+					imgDaemon = false
+					imgRemote = false
+				} else if strings.HasPrefix(img, "/") || strings.HasPrefix(img, ".") {
 					local = true
 					imgDaemon = false
 					imgRemote = false
@@ -78,6 +100,14 @@ var loadImageCmd = &cobra.Command{
 			}
 		}
 
+		if args[0] == "-" {
+                        tmp, err := saveFile(os.Stdin)
+                        if err != nil {
+                                exit.Error(reason.GuestImageLoad, "Failed to save stdin", err)
+                        }
+                        args = []string{tmp}
+		}
+
 		// Currently "image.retrieveImage" always tries to load both from daemon and from remote
 		// There is no way to skip daemon.Image or remote.Image, for the vague "ref" string given.
 		if imgDaemon || imgRemote {