source       *core.FlexVolumeSource
		expectedErrs map[string]string
	}{
		"valid": {
			source:       &core.FlexVolumeSource{Driver: "foo"},
			expectedErrs: map[string]string{},
		},
		"valid with options": {
			source:       &core.FlexVolumeSource{Driver: "foo", Options: map[string]string{"foo": "bar"}},
			expectedErrs: map[string]string{},
		},
		"no driver": {