Remove dependency from OSS to enterprise packages by moving Spanner functions to xorm. (#102692)

* Remove dependency from OSS to enterprise packages by moving Spanner functions to xorm.

pkg/util/xorm/dialect_spanner.go

@@ -10,9 +10,10 @@ import (
 
 	_ "github.com/googleapis/go-sql-spanner"
 	spannerdriver "github.com/googleapis/go-sql-spanner"
+	"google.golang.org/api/option"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 	"xorm.io/core"
-
-	spannerext "github.com/grafana/grafana/pkg/extensions/spanner"
 )
 
 func init() {
@@ -381,7 +382,7 @@ func (s *spanner) CreateSequenceGenerator(db *sql.DB) (SequenceGenerator, error)
 		return nil, err
 	}
 
-	if spannerext.UsePlainText(connectorConfig) {
+	if UsePlainText(connectorConfig) {
 		// Plain-text means we're either using spannertest or Spanner emulator.
 		// Switch to fake in-memory sequence number generator in that case.
 		//
@@ -393,3 +394,32 @@ func (s *spanner) CreateSequenceGenerator(db *sql.DB) (SequenceGenerator, error)
 
 	return newSequenceGenerator(db), nil
 }
+
+func UsePlainText(connectorConfig spannerdriver.ConnectorConfig) bool {
+	if strval, ok := connectorConfig.Params["useplaintext"]; ok {
+		if val, err := strconv.ParseBool(strval); err == nil {
+			return val
+		}
+	}
+	return false
+}
+
+// SpannerConnectorConfigToClientOptions is adapted from https://github.com/googleapis/go-sql-spanner/blob/main/driver.go#L341-L477, from version 1.11.1.
+func SpannerConnectorConfigToClientOptions(connectorConfig spannerdriver.ConnectorConfig) []option.ClientOption {
+	var opts []option.ClientOption
+	if connectorConfig.Host != "" {
+		opts = append(opts, option.WithEndpoint(connectorConfig.Host))
+	}
+	if strval, ok := connectorConfig.Params["credentials"]; ok {
+		opts = append(opts, option.WithCredentialsFile(strval))
+	}
+	if strval, ok := connectorConfig.Params["credentialsjson"]; ok {
+		opts = append(opts, option.WithCredentialsJSON([]byte(strval)))
+	}
+	if UsePlainText(connectorConfig) {
+		opts = append(opts,
+			option.WithGRPCDialOption(grpc.WithTransportCredentials(insecure.NewCredentials())),
+			option.WithoutAuthentication())
+	}
+	return opts
+}