plugins: restart killed plugins

pkg/plugins/backend/log-wrapper.go

@@ -11,11 +11,21 @@ type LogWrapper struct {
 	Logger glog.Logger
 }
 
-func (lw LogWrapper) Trace(msg string, args ...interface{}) {}
-func (lw LogWrapper) Debug(msg string, args ...interface{}) {}
-func (lw LogWrapper) Info(msg string, args ...interface{})  {}
-func (lw LogWrapper) Warn(msg string, args ...interface{})  {}
-func (lw LogWrapper) Error(msg string, args ...interface{}) {}
+func (lw LogWrapper) Trace(msg string, args ...interface{}) {
+	glog.Debug2(msg, args...)
+}
+func (lw LogWrapper) Debug(msg string, args ...interface{}) {
+	glog.Debug2(msg, args...)
+}
+func (lw LogWrapper) Info(msg string, args ...interface{}) {
+	glog.Info2(msg, args...)
+}
+func (lw LogWrapper) Warn(msg string, args ...interface{}) {
+	glog.Warn2(msg, args...)
+}
+func (lw LogWrapper) Error(msg string, args ...interface{}) {
+	glog.Error2(msg, args...)
+}
 
 func (lw LogWrapper) IsTrace() bool { return true }
 func (lw LogWrapper) IsDebug() bool { return true }

pkg/plugins/datasource_plugin.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+	"time"
 
 	"github.com/grafana/grafana/pkg/log"
 	"github.com/grafana/grafana/pkg/models"
@@ -71,6 +72,13 @@ func buildExecutablePath(pluginDir, executable, os, arch string) string {
 func (p *DataSourcePlugin) initBackendPlugin(log log.Logger) error {
 	p.log = log.New("plugin-id", p.Id)
 
+	p.spawnSubProcess()
+	go p.reattachKilledProcess()
+
+	return nil
+}
+
+func (p *DataSourcePlugin) spawnSubProcess() error {
 	cmd := buildExecutablePath(p.PluginDir, p.Executable, runtime.GOOS, runtime.GOARCH)
 
 	p.client = plugin.NewClient(&plugin.ClientConfig{
@@ -94,12 +102,28 @@ func (p *DataSourcePlugin) initBackendPlugin(log log.Logger) error {
 	plugin := raw.(shared.TsdbPlugin)
 
 	tsdb.RegisterTsdbQueryEndpoint(p.Id, func(dsInfo *models.DataSource) (tsdb.TsdbQueryEndpoint, error) {
-		return &shared.TsdbWrapper{TsdbPlugin: plugin}, nil
+		return &shared.DatasourcePluginWrapper{TsdbPlugin: plugin}, nil
 	})
 
 	return nil
 }
 
+func (p *DataSourcePlugin) reattachKilledProcess() {
+	ticker := time.NewTicker(time.Second * 1)
+
+	for {
+		select {
+		case <-ticker.C:
+			if p.client.Exited() {
+				err := p.spawnSubProcess()
+				if err != nil {
+					p.log.Error("Failed to spawn subprocess")
+				}
+			}
+		}
+	}
+}
+
 func (p *DataSourcePlugin) Kill() {
 	if p.client != nil {
 		p.client.Kill()

pkg/tsdb/models/proxy/wrapper.go → pkg/tsdb/models/proxy/datasource_plugin_wrapper.go

@@ -9,11 +9,11 @@ import (
 	"golang.org/x/net/context"
 )
 
-type TsdbWrapper struct {
+type DatasourcePluginWrapper struct {
 	TsdbPlugin
 }
 
-func (tw *TsdbWrapper) Query(ctx context.Context, ds *models.DataSource, query *tsdb.TsdbQuery) (*tsdb.Response, error) {
+func (tw *DatasourcePluginWrapper) Query(ctx context.Context, ds *models.DataSource, query *tsdb.TsdbQuery) (*tsdb.Response, error) {
 	jsonData, err := ds.JsonData.MarshalJSON()
 	if err != nil {
 		return nil, err