kms: testing: add KMS test dummy registry

Add registry similar to the providers one. This allows testers to
add and use GetKMSTestDummy() to create stripped down provider
instances suitable for use in unit tests.

Signed-off-by: Marcel Lauhoff <marcel.lauhoff@suse.com>

internal/kms/dummy.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2022 The Ceph-CSI Authors.
+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 kms
+
+import "encoding/base64"
+
+type TestDummyFunc func() EncryptionKMS
+
+type ProviderTest struct {
+	UniqueID        string
+	CreateTestDummy TestDummyFunc
+}
+
+type kmsTestProviderList struct {
+	providers map[string]ProviderTest
+}
+
+var kmsTestManager = kmsTestProviderList{providers: map[string]ProviderTest{}}
+
+func RegisterTestProvider(provider ProviderTest) bool {
+	kmsTestManager.providers[provider.UniqueID] = provider
+
+	return true
+}
+
+func GetKMSTestDummy(kmsID string) EncryptionKMS {
+	provider, ok := kmsTestManager.providers[kmsID]
+	if !ok {
+		return nil
+	}
+
+	return provider.CreateTestDummy()
+}
+
+func GetKMSTestProvider() map[string]ProviderTest {
+	return kmsTestManager.providers
+}
+
+func newDefaultTestDummy() EncryptionKMS {
+	return secretsKMS{passphrase: base64.URLEncoding.EncodeToString(
+		[]byte("test dummy passphrase"))}
+}
+
+func newSecretsMetadataTestDummy() EncryptionKMS {
+	smKMS := secretsMetadataKMS{}
+	smKMS.secretsKMS = secretsKMS{passphrase: base64.URLEncoding.EncodeToString(
+		[]byte("test dummy passphrase"))}
+
+	return smKMS
+}
+
+var _ = RegisterTestProvider(ProviderTest{
+	UniqueID:        kmsTypeSecretsMetadata,
+	CreateTestDummy: newSecretsMetadataTestDummy,
+})
+
+var _ = RegisterTestProvider(ProviderTest{
+	UniqueID:        DefaultKMSType,
+	CreateTestDummy: newDefaultTestDummy,
+})