Search: create a separate HTTP endpoint (#55634)

* search: create a separate http endpoint

* search: extract api uri

* search: rename uri

* search: replicate the readiness check

* search: replicate the readiness check metric

* search: update mock

pkg/services/searchV2/http.go

@@ -0,0 +1,76 @@
+package searchV2
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/api/routing"
+	"github.com/grafana/grafana/pkg/middleware"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type SearchHTTPService interface {
+	RegisterHTTPRoutes(storageRoute routing.RouteRegister)
+}
+
+type searchHTTPService struct {
+	search SearchService
+}
+
+func ProvideSearchHTTPService(search SearchService) SearchHTTPService {
+	return &searchHTTPService{search: search}
+}
+
+func (s *searchHTTPService) RegisterHTTPRoutes(storageRoute routing.RouteRegister) {
+	storageRoute.Post("/", middleware.ReqSignedIn, routing.Wrap(s.doQuery))
+}
+
+func (s *searchHTTPService) doQuery(c *models.ReqContext) response.Response {
+	searchReadinessCheckResp := s.search.IsReady(c.Req.Context(), c.OrgID)
+	if !searchReadinessCheckResp.IsReady {
+		dashboardSearchNotServedRequestsCounter.With(prometheus.Labels{
+			"reason": searchReadinessCheckResp.Reason,
+		}).Inc()
+
+		bytes, err := (&data.Frame{
+			Name: "Loading",
+		}).MarshalJSON()
+
+		if err != nil {
+			return response.Error(500, "error marshalling response", err)
+		}
+		return response.JSON(200, bytes)
+	}
+
+	body, err := io.ReadAll(c.Req.Body)
+	if err != nil {
+		return response.Error(500, "error reading bytes", err)
+	}
+
+	query := &DashboardQuery{}
+	err = json.Unmarshal(body, query)
+	if err != nil {
+		return response.Error(400, "error parsing body", err)
+	}
+
+	resp := s.search.doDashboardQuery(c.Req.Context(), c.SignedInUser, c.OrgID, *query)
+
+	if resp.Error != nil {
+		return response.Error(500, "error handling search request", resp.Error)
+	}
+
+	if len(resp.Frames) != 1 {
+		return response.Error(500, "invalid search response", errors.New("invalid search response"))
+	}
+
+	bytes, err := resp.Frames[0].MarshalJSON()
+	if err != nil {
+		return response.Error(500, "error marshalling response", err)
+	}
+
+	return response.JSON(200, bytes)
+}