Zipkin: Decouple backend (#107312)

* Zipkin: Decouple backend

* Update

* Remove core import

.golangci.yml

@@ -103,6 +103,8 @@ linters:
             - '**/pkg/tsdb/cloudwatch/**/*'
             - '**/pkg/tsdb/loki/*'
             - '**/pkg/tsdb/loki/**/*'
+            - '**/pkg/tsdb/zipkin/*'
+            - '**/pkg/tsdb/zipkin/**/*'
             - '**/pkg/tsdb/jaeger/*'
             - '**/pkg/tsdb/jaeger/**/*'
           deny:

pkg/tsdb/zipkin/standalone/datasource.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
+
+	"github.com/grafana/grafana/pkg/tsdb/zipkin"
+)
+
+var (
+	_ backend.QueryDataHandler    = (*Datasource)(nil)
+	_ backend.CheckHealthHandler  = (*Datasource)(nil)
+	_ backend.CallResourceHandler = (*Datasource)(nil)
+)
+
+func NewDatasource(context.Context, backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
+	return &Datasource{
+		Service: zipkin.ProvideService(httpclient.NewProvider()),
+	}, nil
+}
+
+type Datasource struct {
+	Service *zipkin.Service
+}
+
+func (d *Datasource) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
+	return d.Service.QueryData(ctx, req)
+}
+
+func (d *Datasource) CallResource(ctx context.Context, req *backend.CallResourceRequest, sender backend.CallResourceResponseSender) error {
+	return d.Service.CallResource(ctx, req, sender)
+}
+
+func (d *Datasource) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, error) {
+	return d.Service.CheckHealth(ctx, req)
+}

pkg/tsdb/zipkin/standalone/main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"os"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/log"
+)
+
+func main() {
+	// Start listening to requests sent from Grafana. This call is blocking so
+	// it won't finish until Grafana shuts down the process or the plugin choose
+	// to exit by itself using os.Exit. Manage automatically manages life cycle
+	// of datasource instances. It accepts datasource instance factory as first
+	// argument. This factory will be automatically called on incoming request
+	// from Grafana to create different instances of SampleDatasource (per datasource
+	// ID). When datasource configuration changed Dispose method will be called and
+	// new datasource instance created using NewSampleDatasource factory.
+	if err := datasource.Manage("zipkin", NewDatasource, datasource.ManageOpts{}); err != nil {
+		log.DefaultLogger.Error(err.Error())
+		os.Exit(1)
+	}
+}

pkg/tsdb/zipkin/zipkin.go

@@ -7,10 +7,9 @@ import (
 
 	"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/httpclient"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/resource/httpadapter"
-
-	"github.com/grafana/grafana/pkg/infra/httpclient"
 )
 
 var logger = backend.NewLoggerWith("logger", "tsdb.zipkin")
@@ -19,7 +18,7 @@ type Service struct {
 	im instancemgmt.InstanceManager
 }
 
-func ProvideService(httpClientProvider httpclient.Provider) *Service {
+func ProvideService(httpClientProvider *httpclient.Provider) *Service {
 	return &Service{
 		im: datasource.NewInstanceManager(newInstanceSettings(httpClientProvider)),
 	}
@@ -29,7 +28,7 @@ type datasourceInfo struct {
 	ZipkinClient ZipkinClient
 }
 
-func newInstanceSettings(httpClientProvider httpclient.Provider) datasource.InstanceFactoryFunc {
+func newInstanceSettings(httpClientProvider *httpclient.Provider) datasource.InstanceFactoryFunc {
 	return func(ctx context.Context, settings backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
 		httpClientOptions, err := settings.HTTPClientOptions(ctx)
 		if err != nil {

public/app/plugins/datasource/zipkin/plugin.json

@@ -3,6 +3,7 @@
   "name": "Zipkin",
   "id": "zipkin",
   "category": "tracing",
+  "executable": "gpx_zipkin",
 
   "backend": true,
   "metrics": true,