Return an error instead of panicking on a valueless mount option

pkg/flags/mountopt_test.go

@@ -0,0 +1,27 @@
+package flags
+
+import "testing"
+
+// A mount option without a value used to index past the end of the split.
+func TestParseMountOptionsWithoutValue(t *testing.T) {
+	tests := []struct {
+		in      string
+		wantErr bool
+	}{
+		{"readonly=true", false},
+		{"readonly=false", false},
+		{"readonly", true},
+		{"readonly=", false},
+		{"bogus=1", true},
+	}
+
+	for _, tc := range tests {
+		_, err := parseMountOptions(tc.in)
+		if tc.wantErr && err == nil {
+			t.Errorf("%q: expected an error, got none", tc.in)
+		}
+		if !tc.wantErr && err != nil {
+			t.Errorf("%q: unexpected error: %v", tc.in, err)
+		}
+	}
+}

pkg/flags/podspec_helper.go

@@ -955,6 +955,9 @@ func parseMountOptions(options string) (*util.OrderedMap, error) {
 		pair := strings.SplitN(slice, "=", 2)
 		switch strings.ToLower(pair[0]) {
 		case "readonly":
+			if len(pair) != 2 {
+				return nil, fmt.Errorf("mount option %q requires a value, for example readOnly=true", pair[0])
+			}
 			mountOptions.Set("readonly", pair[1])
 		default:
 			return nil, fmt.Errorf("unknown mount option %q", pair[0])
@@ -994,11 +997,6 @@ func getMountInfo(volume string) *MountInfo {
 	configSlices := strings.SplitN(volume, ":", 2)
 	var mountInfo MountInfo
 	if len(configSlices) == 2 {
-		readOnlySlices := strings.SplitN(configSlices[1], "=", 2)
-		switch strings.ToLower(readOnlySlices[0]) {
-		case "readonly":
-
-		}
 		mountInfo.MountOptions = configSlices[1]
 	}
 	slices := strings.SplitN(configSlices[0], "/", 2)