merge backend-datasource and datasource type

pkg/plugins/datasource_plugin.go

@@ -3,7 +3,16 @@ package plugins
 import (
 	"encoding/json"
 	"os"
+	"os/exec"
+	"path"
 	"path/filepath"
+
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/plugins/backend"
+	"github.com/grafana/grafana/pkg/tsdb"
+	shared "github.com/grafana/grafana/pkg/tsdb/models/proxy"
+	plugin "github.com/hashicorp/go-plugin"
 )
 
 type DataSourcePlugin struct {
@@ -16,6 +25,12 @@ type DataSourcePlugin struct {
 	Mixed        bool              `json:"mixed,omitempty"`
 	HasQueryHelp bool              `json:"hasQueryHelp,omitempty"`
 	Routes       []*AppPluginRoute `json:"routes"`
+
+	Backend    bool   `json:"backend,omitempty"`
+	Executable string `json:"executable,omitempty"`
+
+	log    log.Logger
+	client *plugin.Client
 }
 
 func (p *DataSourcePlugin) Load(decoder *json.Decoder, pluginDir string) error {
@@ -39,3 +54,37 @@ func (p *DataSourcePlugin) Load(decoder *json.Decoder, pluginDir string) error {
 	DataSources[p.Id] = p
 	return nil
 }
+
+func (p *DataSourcePlugin) initBackendPlugin(log log.Logger) error {
+	p.log = log.New("plugin-id", p.Id)
+
+	p.client = plugin.NewClient(&plugin.ClientConfig{
+		HandshakeConfig:  handshakeConfig,
+		Plugins:          map[string]plugin.Plugin{p.Id: &shared.TsdbPluginImpl{}},
+		Cmd:              exec.Command(path.Join(p.PluginDir, p.Executable)),
+		AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
+		Logger:           backend.LogWrapper{Logger: p.log},
+	})
+
+	rpcClient, err := p.client.Client()
+	if err != nil {
+		return err
+	}
+
+	raw, err := rpcClient.Dispense(p.Id)
+	if err != nil {
+		return err
+	}
+
+	plugin := raw.(shared.TsdbPlugin)
+
+	tsdb.RegisterTsdbQueryEndpoint(p.Id, func(dsInfo *models.DataSource) (tsdb.TsdbQueryEndpoint, error) {
+		return &shared.TsdbWrapper{TsdbPlugin: plugin}, nil
+	})
+
+	return nil
+}
+
+func (p *DataSourcePlugin) Kill() {
+	p.client.Kill()
+}