fix: handle DOS-style path for Dockerfile in minikube build

cmd/minikube/cmd/image.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/minikube/pkg/minikube/exit"
 	"k8s.io/minikube/pkg/minikube/image"
 	"k8s.io/minikube/pkg/minikube/machine"
+	"k8s.io/minikube/pkg/minikube/out"
 	"k8s.io/minikube/pkg/minikube/reason"
 	docker "k8s.io/minikube/third_party/go-dockerclient"
 )
@@ -310,6 +311,12 @@ var buildImageCmd = &cobra.Command{
 				// Otherwise, assume it's a tar
 			}
 		}
+		if runtime.GOOS == "windows" && strings.Contains(dockerFile, "\\") {
+			// if dockerFile is a DOS path, and user did not explicitly forbid this conversion, translate it into UNIX path
+			// because we are going to build this image in UNIX environment
+			out.String("minikube detects that you are using DOS-style path %s. minikube will convert it to UNIX-style by replacing all \\ to /", dockerFile)
+			dockerFile = strings.ReplaceAll(dockerFile, "\\", "/")
+		}
 		if err := machine.BuildImage(img, dockerFile, tag, push, buildEnv, buildOpt, []*config.Profile{profile}, allNodes, nodeName); err != nil {
 			exit.Error(reason.GuestImageBuild, "Failed to build image", err)
 		}

test/integration/functional_test.go

@@ -299,7 +299,7 @@ func validateImageCommands(ctx context.Context, t *testing.T, profile string) {
 	// docs: Make sure image building works by `minikube image build`
 	t.Run("ImageBuild", func(t *testing.T) {
 		MaybeParallel(t)
-
+		
 		if _, err := Run(t, exec.CommandContext(ctx, Target(), "-p", profile, "ssh", "pgrep", "buildkitd")); err == nil {
 			t.Errorf("buildkitd process is running, should not be running until `minikube image build` is ran")
 		}