PostgreSQL: Decouple plugin (#111620)

pkg/tsdb/grafana-postgresql-datasource/postgres_service.go

@@ -0,0 +1,80 @@
+package postgres
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
+
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
+	"github.com/grafana/grafana/pkg/setting"
+	sqlengpgx "github.com/grafana/grafana/pkg/tsdb/grafana-postgresql-datasource/pgx"
+	"github.com/grafana/grafana/pkg/tsdb/grafana-postgresql-datasource/sqleng"
+)
+
+type Service struct {
+	im       instancemgmt.InstanceManager
+	features featuremgmt.FeatureToggles
+}
+
+func ProvideService(cfg *setting.Cfg, features featuremgmt.FeatureToggles) *Service {
+	logger := backend.NewLoggerWith("logger", "tsdb.postgres")
+	s := &Service{
+		im:       datasource.NewInstanceManager(NewInstanceSettings(logger, features, cfg.DataPath)),
+		features: features,
+	}
+	return s
+}
+
+// NOTE: do not put any business logic into this method. it's whole job is to forward the call "inside"
+func (s *Service) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, error) {
+	if s.features.IsEnabled(ctx, featuremgmt.FlagPostgresDSUsePGX) {
+		dsHandler, err := s.getDSInfoPGX(ctx, req.PluginContext)
+		if err != nil {
+			return sqlengpgx.ErrToHealthCheckResult(err)
+		}
+		return dsHandler.CheckHealth(ctx, req)
+	} else {
+		dsHandler, err := s.getDSInfo(ctx, req.PluginContext)
+		if err != nil {
+			return sqleng.ErrToHealthCheckResult(err)
+		}
+		return dsHandler.CheckHealth(ctx, req)
+	}
+}
+
+// NOTE: do not put any business logic into this method. it's whole job is to forward the call "inside"
+func (s *Service) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
+	if s.features.IsEnabled(ctx, featuremgmt.FlagPostgresDSUsePGX) {
+		dsInfo, err := s.getDSInfoPGX(ctx, req.PluginContext)
+		if err != nil {
+			return nil, err
+		}
+		return dsInfo.QueryData(ctx, req)
+	} else {
+		dsInfo, err := s.getDSInfo(ctx, req.PluginContext)
+		if err != nil {
+			return nil, err
+		}
+		return dsInfo.QueryData(ctx, req)
+	}
+}
+
+func (s *Service) getDSInfo(ctx context.Context, pluginCtx backend.PluginContext) (*sqleng.DataSourceHandler, error) {
+	i, err := s.im.Get(ctx, pluginCtx)
+	if err != nil {
+		return nil, err
+	}
+	instance := i.(*sqleng.DataSourceHandler)
+	return instance, nil
+}
+
+func (s *Service) getDSInfoPGX(ctx context.Context, pluginCtx backend.PluginContext) (*sqlengpgx.DataSourceHandler, error) {
+	i, err := s.im.Get(ctx, pluginCtx)
+	if err != nil {
+		return nil, err
+	}
+	instance := i.(*sqlengpgx.DataSourceHandler)
+	return instance, nil
+}