Zipkin: Improve error source (#99099)

* Zipkin: Improve error source

* Revert file name change

pkg/tsdb/zipkin/client.go

@@ -118,7 +118,7 @@ func (z *ZipkinClient) Traces(serviceName string, spanName string) ([][]model.Sp
 func (z *ZipkinClient) Trace(traceId string) ([]model.SpanModel, error) {
 	trace := []model.SpanModel{}
 	if traceId == "" {
-		return trace, errors.New("invalid/empty traceId")
+		return trace, backend.DownstreamError(errors.New("invalid/empty traceId"))
 	}
 
 	traceUrl, err := url.JoinPath(z.url, "/api/v2/trace", url.QueryEscape(traceId))
@@ -128,6 +128,9 @@ func (z *ZipkinClient) Trace(traceId string) ([]model.SpanModel, error) {
 
 	res, err := z.httpClient.Get(traceUrl)
 	if err != nil {
+		if backend.IsDownstreamHTTPError(err) {
+			return trace, backend.DownstreamError(err)
+		}
 		return trace, err
 	}
 
@@ -138,6 +141,15 @@ func (z *ZipkinClient) Trace(traceId string) ([]model.SpanModel, error) {
 			}
 		}
 	}()
+
+	if res != nil && res.StatusCode/100 != 2 {
+		err := backend.DownstreamError(fmt.Errorf("request failed: %s", res.Status))
+		if backend.ErrorSourceFromHTTPStatus(res.StatusCode) == backend.ErrorSourceDownstream {
+			return trace, backend.DownstreamError(err)
+		}
+		return trace, err
+	}
+
 	if err := json.NewDecoder(res.Body).Decode(&trace); err != nil {
 		return trace, err
 	}

pkg/tsdb/zipkin/client_test.go

@@ -2,11 +2,14 @@ package zipkin
 
 import (
 	"encoding/json"
+	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
 	"testing"
 
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/log"
 	"github.com/openzipkin/zipkin-go/model"
 	"github.com/stretchr/testify/assert"
@@ -17,29 +20,37 @@ func TestZipkinClient_Services(t *testing.T) {
 		name           string
 		mockResponse   string
 		mockStatusCode int
+		mockStatus     string
 		expectedResult []string
 		expectError    bool
+		expectedError  error
 	}{
 		{
 			name:           "Successful response",
 			mockResponse:   `["service1", "service2"]`,
 			mockStatusCode: http.StatusOK,
+			mockStatus:     "OK",
 			expectedResult: []string{"service1", "service2"},
 			expectError:    false,
+			expectedError:  nil,
 		},
 		{
 			name:           "Non-200 response",
 			mockResponse:   "",
 			mockStatusCode: http.StatusInternalServerError,
+			mockStatus:     "Internal Server Error",
 			expectedResult: []string{},
 			expectError:    true,
+			expectedError:  backend.DownstreamError(fmt.Errorf("request failed: Internal Server Error")),
 		},
 		{
 			name:           "Invalid JSON response",
 			mockResponse:   `{invalid json`,
 			mockStatusCode: http.StatusOK,
+			mockStatus:     "OK",
 			expectedResult: []string{},
 			expectError:    true,
+			expectedError:  errors.New("invalid character 'i' looking for beginning of value"),
 		},
 	}
 

pkg/tsdb/zipkin/handler_querydata.go

@@ -39,7 +39,7 @@ func queryData(ctx context.Context, dsInfo *datasourceInfo, req *backend.QueryDa
 			traces, err := dsInfo.ZipkinClient.Trace(query.Query)
 			if err != nil {
 				es := backend.ErrorSourcePlugin
-				if backend.IsDownstreamHTTPError(err) {
+				if backend.IsDownstreamError(err) {
 					es = backend.ErrorSourceDownstream
 				}
 				response.Responses[q.RefID] = backend.DataResponse{