Forward oauth tokens after prometheus datasource migration (#43686)

* create the prom client

* implement lru cache of prometheus clients based on auth headers

* linter

pkg/tsdb/prometheus/client/provider.go

@@ -1,53 +0,0 @@
-package client
-
-import (
-	"strings"
-
-	"github.com/grafana/grafana/pkg/tsdb/prometheus/middleware"
-
-	sdkhttpclient "github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
-	"github.com/grafana/grafana/pkg/infra/httpclient"
-	"github.com/grafana/grafana/pkg/infra/log"
-	"github.com/prometheus/client_golang/api"
-	apiv1 "github.com/prometheus/client_golang/api/prometheus/v1"
-)
-
-func Create(url string, httpOpts sdkhttpclient.Options, clientProvider httpclient.Provider, jsonData map[string]interface{}, plog log.Logger) (apiv1.API, error) {
-	customParamsMiddleware := middleware.CustomQueryParameters(plog)
-	middlewares := []sdkhttpclient.Middleware{customParamsMiddleware}
-	if shouldForceGet(jsonData) {
-		middlewares = append(middlewares, middleware.ForceHttpGet(plog))
-	}
-	httpOpts.Middlewares = middlewares
-
-	roundTripper, err := clientProvider.GetTransport(httpOpts)
-	if err != nil {
-		return nil, err
-	}
-
-	cfg := api.Config{
-		Address:      url,
-		RoundTripper: roundTripper,
-	}
-
-	client, err := api.NewClient(cfg)
-	if err != nil {
-		return nil, err
-	}
-
-	return apiv1.NewAPI(client), nil
-}
-
-func shouldForceGet(settingsJson map[string]interface{}) bool {
-	methodInterface, exists := settingsJson["httpMethod"]
-	if !exists {
-		return false
-	}
-
-	method, ok := methodInterface.(string)
-	if !ok {
-		return false
-	}
-
-	return strings.ToLower(method) == "get"
-}

pkg/tsdb/prometheus/client/provider_test.go

@@ -1,47 +0,0 @@
-package client
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestForceGet(t *testing.T) {
-	t.Run("With nil jsonOpts, should not force get-method", func(t *testing.T) {
-		var jsonOpts map[string]interface{}
-		require.False(t, shouldForceGet(jsonOpts))
-	})
-
-	t.Run("With empty jsonOpts, should not force get-method", func(t *testing.T) {
-		jsonOpts := make(map[string]interface{})
-		require.False(t, shouldForceGet(jsonOpts))
-	})
-
-	t.Run("With httpMethod=nil, should not not force get-method", func(t *testing.T) {
-		jsonOpts := map[string]interface{}{
-			"httpMethod": nil,
-		}
-		require.False(t, shouldForceGet(jsonOpts))
-	})
-
-	t.Run("With httpMethod=post, should not force get-method", func(t *testing.T) {
-		jsonOpts := map[string]interface{}{
-			"httpMethod": "POST",
-		}
-		require.False(t, shouldForceGet(jsonOpts))
-	})
-
-	t.Run("With httpMethod=get, should force get-method", func(t *testing.T) {
-		jsonOpts := map[string]interface{}{
-			"httpMethod": "get",
-		}
-		require.True(t, shouldForceGet(jsonOpts))
-	})
-
-	t.Run("With httpMethod=GET, should force get-method", func(t *testing.T) {
-		jsonOpts := map[string]interface{}{
-			"httpMethod": "GET",
-		}
-		require.True(t, shouldForceGet(jsonOpts))
-	})
-}