Prometheus: Remove cache, pass headers in request, simplify client cr…

…eation for resource calls and custom client (#51436)

* Remove cache, pass headers in request, simplify client creation

* Add test for http options creation

pkg/services/featuremgmt/manager.go

@@ -162,7 +162,8 @@ func (fm *FeatureManager) HandleGetSettings(c *models.ReqContext) {
 }
 
 // WithFeatures is used to define feature toggles for testing.
-// The arguments are a list of strings that are optionally followed by a boolean value
+// The arguments are a list of strings that are optionally followed by a boolean value for example:
+// WithFeatures([]interface{}{"my_feature", "other_feature"}) or WithFeatures([]interface{}{"my_feature", true})
 func WithFeatures(spec ...interface{}) *FeatureManager {
 	count := len(spec)
 	enabled := make(map[string]bool, count)

pkg/tsdb/prometheus/buffered/client.go

@@ -5,11 +5,11 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/grafana/grafana-azure-sdk-go/azsettings"
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	sdkhttpclient "github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
-	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/buffered/azureauth"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/middleware"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/utils"
@@ -20,7 +20,7 @@ import (
 
 // CreateTransportOptions creates options for the http client. Probably should be shared and should not live in the
 // buffered package.
-func CreateTransportOptions(settings backend.DataSourceInstanceSettings, cfg *setting.Cfg, features featuremgmt.FeatureToggles, logger log.Logger) (*sdkhttpclient.Options, error) {
+func CreateTransportOptions(settings backend.DataSourceInstanceSettings, azureSettings *azsettings.AzureSettings, features featuremgmt.FeatureToggles, logger log.Logger) (*sdkhttpclient.Options, error) {
 	opts, err := settings.HTTPClientOptions()
 	if err != nil {
 		return nil, err
@@ -41,7 +41,7 @@ func CreateTransportOptions(settings backend.DataSourceInstanceSettings, cfg *se
 
 	// Azure authentication is experimental (#35857)
 	if features.IsEnabled(featuremgmt.FlagPrometheusAzureAuth) {
-		err = azureauth.ConfigureAzureAuthentication(settings, cfg.Azure, &opts)
+		err = azureauth.ConfigureAzureAuthentication(settings, azureSettings, &opts)
 		if err != nil {
 			return nil, fmt.Errorf("error configuring Azure auth: %v", err)
 		}

pkg/tsdb/prometheus/buffered/client_test.go

@@ -0,0 +1,27 @@
+package buffered
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana-azure-sdk-go/azsettings"
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/grafana/grafana/pkg/infra/log/logtest"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateTransportOptions(t *testing.T) {
+	t.Run("creates correct options object", func(t *testing.T) {
+		settings := backend.DataSourceInstanceSettings{
+			BasicAuthEnabled: false,
+			BasicAuthUser:    "",
+			JSONData:         []byte(`{"httpHeaderName1": "foo"}`),
+			DecryptedSecureJSONData: map[string]string{
+				"httpHeaderValue1": "bar",
+			},
+		}
+		opts, err := CreateTransportOptions(settings, &azsettings.AzureSettings{}, featuremgmt.WithFeatures(), &logtest.Fake{})
+		require.NoError(t, err)
+		require.Equal(t, map[string]string{"foo": "bar"}, opts.Headers)
+	})
+}