Encryption: Refactor secrets service (#41771)

* Refactor kmsproviders pkg

* Update tests

* Fix linting

Co-authored-by: Joan López de la Franca Beltran <joanjan14@gmail.com>

pkg/services/kmsproviders/kmsproviders.go

@@ -0,0 +1,11 @@
+package kmsproviders
+
+import "github.com/grafana/grafana/pkg/services/secrets"
+
+const (
+	Default = "secretKey"
+)
+
+type Service interface {
+	Provide() (map[string]secrets.Provider, error)
+}

pkg/services/kmsproviders/osskmsproviders/osskmsproviders.go

@@ -0,0 +1,31 @@
+package osskmsproviders
+
+import (
+	"github.com/grafana/grafana/pkg/services/encryption"
+	"github.com/grafana/grafana/pkg/services/kmsproviders"
+	"github.com/grafana/grafana/pkg/services/secrets"
+	grafana "github.com/grafana/grafana/pkg/services/secrets/defaultprovider"
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type Service struct {
+	enc      encryption.Internal
+	settings setting.Provider
+}
+
+func ProvideService(enc encryption.Internal, settings setting.Provider) Service {
+	return Service{
+		enc:      enc,
+		settings: settings,
+	}
+}
+
+func (s Service) Provide() (map[string]secrets.Provider, error) {
+	if !s.settings.IsFeatureToggleEnabled(secrets.EnvelopeEncryptionFeatureToggle) {
+		return nil, nil
+	}
+
+	return map[string]secrets.Provider{
+		kmsproviders.Default: grafana.New(s.settings, s.enc),
+	}, nil
+}