Datasource: Shared HTTP client provider for core backend data sources and any data source using the data source proxy (#33439)

Uses new httpclient package from grafana-plugin-sdk-go introduced 
via grafana/grafana-plugin-sdk-go#328. 
Replaces the GetHTTPClient, GetTransport, GetTLSConfig methods defined 
on DataSource model.
Longer-term the goal is to migrate core HTTP backend data sources to use the 
SDK contracts and using httpclient.Provider for creating HTTP clients and such.

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/tsdb/influxdb/flux/executor_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/grafana/grafana-plugin-sdk-go/experimental"
 	"github.com/grafana/grafana/pkg/components/securejsondata"
 	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/infra/httpclient"
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -226,7 +227,7 @@ func TestRealQuery(t *testing.T) {
 			}),
 		}
 
-		runner, err := runnerFromDataSource(dsInfo)
+		runner, err := runnerFromDataSource(httpclient.NewProvider(), dsInfo)
 		require.NoError(t, err)
 
 		dr := executeQuery(context.Background(), queryModel{

pkg/tsdb/influxdb/flux/flux.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/grafana/grafana/pkg/infra/httpclient"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/plugins"
@@ -22,13 +23,13 @@ func init() {
 
 // Query builds flux queries, executes them, and returns the results.
 //nolint: staticcheck // plugins.DataQuery deprecated
-func Query(ctx context.Context, dsInfo *models.DataSource, tsdbQuery plugins.DataQuery) (
+func Query(ctx context.Context, httpClientProvider httpclient.Provider, dsInfo *models.DataSource, tsdbQuery plugins.DataQuery) (
 	plugins.DataResponse, error) {
 	glog.Debug("Received a query", "query", tsdbQuery)
 	tRes := plugins.DataResponse{
 		Results: make(map[string]plugins.DataQueryResult),
 	}
-	r, err := runnerFromDataSource(dsInfo)
+	r, err := runnerFromDataSource(httpClientProvider, dsInfo)
 	if err != nil {
 		return plugins.DataResponse{}, err
 	}
@@ -69,7 +70,7 @@ func (r *runner) runQuery(ctx context.Context, fluxQuery string) (*api.QueryTabl
 }
 
 // runnerFromDataSource creates a runner from the datasource model (the datasource instance's configuration).
-func runnerFromDataSource(dsInfo *models.DataSource) (*runner, error) {
+func runnerFromDataSource(httpClientProvider httpclient.Provider, dsInfo *models.DataSource) (*runner, error) {
 	org := dsInfo.JsonData.Get("organization").MustString("")
 	if org == "" {
 		return nil, fmt.Errorf("missing organization in datasource configuration")
@@ -85,7 +86,7 @@ func runnerFromDataSource(dsInfo *models.DataSource) (*runner, error) {
 	}
 
 	opts := influxdb2.DefaultOptions()
-	hc, err := dsInfo.GetHttpClient()
+	hc, err := dsInfo.GetHTTPClient(httpClientProvider)
 	if err != nil {
 		return nil, err
 	}

pkg/tsdb/influxdb/influxdb.go

@@ -9,6 +9,7 @@ import (
 	"path"
 	"strings"
 
+	"github.com/grafana/grafana/pkg/infra/httpclient"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/plugins"
@@ -17,17 +18,21 @@ import (
 )
 
 type Executor struct {
-	// *models.DataSource
-	QueryParser    *InfluxdbQueryParser
-	ResponseParser *ResponseParser
+	httpClientProvider httpclient.Provider
+	QueryParser        *InfluxdbQueryParser
+	ResponseParser     *ResponseParser
 }
 
-//nolint: staticcheck // plugins.DataPlugin deprecated
-func NewExecutor(*models.DataSource) (plugins.DataPlugin, error) {
-	return &Executor{
-		QueryParser:    &InfluxdbQueryParser{},
-		ResponseParser: &ResponseParser{},
-	}, nil
+// nolint:staticcheck // plugins.DataPlugin deprecated
+func New(httpClientProvider httpclient.Provider) func(*models.DataSource) (plugins.DataPlugin, error) {
+	// nolint:staticcheck // plugins.DataPlugin deprecated
+	return func(dsInfo *models.DataSource) (plugins.DataPlugin, error) {
+		return &Executor{
+			httpClientProvider: httpClientProvider,
+			QueryParser:        &InfluxdbQueryParser{},
+			ResponseParser:     &ResponseParser{},
+		}, nil
+	}
 }
 
 var (
@@ -47,7 +52,7 @@ func (e *Executor) DataQuery(ctx context.Context, dsInfo *models.DataSource, tsd
 
 	version := dsInfo.JsonData.Get("version").MustString("")
 	if version == "Flux" {
-		return flux.Query(ctx, dsInfo, tsdbQuery)
+		return flux.Query(ctx, e.httpClientProvider, dsInfo, tsdbQuery)
 	}
 
 	glog.Debug("Making a non-Flux type query")
@@ -74,7 +79,7 @@ func (e *Executor) DataQuery(ctx context.Context, dsInfo *models.DataSource, tsd
 		return plugins.DataResponse{}, err
 	}
 
-	httpClient, err := dsInfo.GetHttpClient()
+	httpClient, err := dsInfo.GetHTTPClient(e.httpClientProvider)
 	if err != nil {
 		return plugins.DataResponse{}, err
 	}