feat(querier): propagate all known alerting headers (#92873)

pkg/registry/apis/query/query.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
-	"strings"
 	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
@@ -135,26 +134,8 @@ func (r *queryREST) Connect(connectCtx context.Context, name string, _ runtime.O
 			return
 		}
 
-		// get headers from the original http req and add them to each sub request
-		// headers are case insensitive, however some datasources still check for camel casing so we have to send them camel cased
-		expectedHeaders := map[string]string{
-			"fromalert":      "FromAlert",
-			"content-type":   "Content-Type",
-			"content-length": "Content-Length",
-			"user-agent":     "User-Agent",
-			"accept":         "Accept",
-		}
-
 		for i := range req.Requests {
-			req.Requests[i].Headers = make(map[string]string)
-			for k, v := range httpreq.Header {
-				headerToSend, ok := expectedHeaders[strings.ToLower(k)]
-				if ok {
-					req.Requests[i].Headers[headerToSend] = v[0]
-				} else {
-					b.log.Warn(fmt.Sprintf("query service received an unexpected header, ignoring it: %s", k))
-				}
-			}
+			req.Requests[i].Headers = ExtractKnownHeaders(httpreq.Header)
 		}
 
 		// Actually run the query