Add new macOS vfkit driver, like hyperkit and qemu

It uses the new Virtualization.framework from macOS 11,
instead of the older Hypervisor.framework (hvf) in QEMU.

pkg/drivers/vfkit/iso.go

@@ -0,0 +1,65 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package vfkit
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/hooklift/iso9660"
+)
+
+// ExtractFile extracts a file from an ISO
+func ExtractFile(isoPath, srcPath, destPath string) error {
+	iso, err := os.Open(isoPath)
+	if err != nil {
+		return err
+	}
+	defer iso.Close()
+
+	r, err := iso9660.NewReader(iso)
+	if err != nil {
+		return err
+	}
+
+	f, err := findFile(r, srcPath)
+	if err != nil {
+		return err
+	}
+
+	dst, err := os.Create(destPath)
+	if err != nil {
+		return err
+	}
+	defer dst.Close()
+
+	_, err = io.Copy(dst, f.Sys().(io.Reader))
+	return err
+}
+
+func findFile(r *iso9660.Reader, path string) (os.FileInfo, error) {
+	// Look through the ISO for a file with a matching path.
+	for f, err := r.Next(); err != io.EOF; f, err = r.Next() {
+		// For some reason file paths in the ISO sometimes contain a '.' character at the end, so strip that off.
+		if strings.TrimSuffix(f.Name(), ".") == path {
+			return f, nil
+		}
+	}
+	return nil, fmt.Errorf("unable to find file %s", path)
+}

pkg/drivers/vfkit/iso_test.go

@@ -0,0 +1,85 @@
+/*
+Copyright 2020 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package vfkit
+
+import (
+	"testing"
+)
+
+func TestExtractFile(t *testing.T) {
+	testDir := t.TempDir()
+
+	tests := []struct {
+		name          string
+		isoPath       string
+		srcPath       string
+		destPath      string
+		expectedError bool
+	}{
+		{
+			name:          "all is right",
+			isoPath:       "iso_test.iso",
+			srcPath:       "/test1.txt",
+			destPath:      testDir + "/test1.txt",
+			expectedError: false,
+		},
+		{
+			name:          "isoPath is error",
+			isoPath:       "tests.iso",
+			srcPath:       "/test1.txt",
+			destPath:      testDir + "/test1.txt",
+			expectedError: true,
+		},
+		{
+			name:          "srcPath is empty",
+			isoPath:       "iso_tests.iso",
+			srcPath:       "",
+			destPath:      testDir + "/test1.txt",
+			expectedError: true,
+		},
+		{
+			name:          "srcPath is error",
+			isoPath:       "iso_tests.iso",
+			srcPath:       "/t1.txt",
+			destPath:      testDir + "/test1.txt",
+			expectedError: true,
+		},
+		{
+			name:          "destPath is empty",
+			isoPath:       "iso_test.iso",
+			srcPath:       "/test1.txt",
+			destPath:      "",
+			expectedError: true,
+		},
+		{
+			name:          "find files in a folder",
+			isoPath:       "./iso_test.iso",
+			srcPath:       "/test2/test2.txt",
+			destPath:      testDir + "/test2.txt",
+			expectedError: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := ExtractFile(tt.isoPath, tt.srcPath, tt.destPath)
+			if (nil != err) != tt.expectedError {
+				t.Errorf("expectedError = %v, get = %v", tt.expectedError, err)
+				return
+			}
+		})
+	}
+}