fix: add missed variable substitution for promql querires (#3584)

pkg/query-service/app/metrics/query_builder.go

@@ -497,7 +497,7 @@ func PromFormattedValue(v interface{}) string {
 	case float32, float64:
 		return fmt.Sprintf("%f", x)
 	case string:
-		return fmt.Sprintf("%s", x)
+		return x
 	case bool:
 		return fmt.Sprintf("%v", x)
 	case []interface{}:
@@ -506,7 +506,12 @@ func PromFormattedValue(v interface{}) string {
 		}
 		switch x[0].(type) {
 		case string, int, float32, float64, bool:
-			return strings.Trim(strings.Join(strings.Fields(fmt.Sprint(x)), "|"), "[]")
+			// list of values joined by | for promql - a value can contain whitespace
+			var str []string
+			for _, sVal := range x {
+				str = append(str, fmt.Sprintf("%v", sVal))
+			}
+			return strings.Join(str, "|")
 		default:
 			zap.L().Error("invalid type for prom formatted value", zap.Any("type", reflect.TypeOf(x[0])))
 			return ""

pkg/query-service/app/parser.go

@@ -1044,5 +1044,29 @@ func ParseQueryRangeParams(r *http.Request) (*v3.QueryRangeParamsV3, *model.ApiE
 		}
 	}
 
+	// replace go template variables in prometheus query
+	if queryRangeParams.CompositeQuery.QueryType == v3.QueryTypePromQL {
+		for _, promQuery := range queryRangeParams.CompositeQuery.PromQueries {
+			if promQuery.Disabled {
+				continue
+			}
+			tmpl := template.New("prometheus-query")
+			tmpl, err := tmpl.Parse(promQuery.Query)
+			if err != nil {
+				return nil, &model.ApiError{Typ: model.ErrorBadData, Err: err}
+			}
+			var query bytes.Buffer
+
+			// replace go template variables
+			querytemplate.AssignReservedVarsV3(queryRangeParams)
+
+			err = tmpl.Execute(&query, queryRangeParams.Variables)
+			if err != nil {
+				return nil, &model.ApiError{Typ: model.ErrorBadData, Err: err}
+			}
+			promQuery.Query = query.String()
+		}
+	}
+
 	return queryRangeParams, nil
 }

pkg/query-service/app/parser_test.go

@@ -757,3 +757,108 @@ func TestParseQueryRangeParamsDashboardVarsSubstitution(t *testing.T) {
 		})
 	}
 }
+
+func TestParseQueryRangeParamsPromQLVars(t *testing.T) {
+	reqCases := []struct {
+		desc           string
+		compositeQuery v3.CompositeQuery
+		variables      map[string]interface{}
+		expectErr      bool
+		errMsg         string
+		expectedQuery  string
+	}{
+		{
+			desc: "valid prom query with dashboard variables",
+			compositeQuery: v3.CompositeQuery{
+				PanelType: v3.PanelTypeGraph,
+				QueryType: v3.QueryTypePromQL,
+				PromQueries: map[string]*v3.PromQuery{
+					"A": {
+						Query:    "http_calls_total{service_name=\"{{.service_name}}\", operation_name=~\"{{.operation_name}}\"}",
+						Disabled: false,
+					},
+				},
+			},
+			variables: map[string]interface{}{
+				"service_name": "route",
+				"operation_name": []interface{}{
+					"GET /route",
+					"POST /route",
+				},
+			},
+			expectErr:     false,
+			expectedQuery: "http_calls_total{service_name=\"route\", operation_name=~\"GET /route|POST /route\"}",
+		},
+		{
+			desc: "valid prom query with dashboard variables",
+			compositeQuery: v3.CompositeQuery{
+				PanelType: v3.PanelTypeGraph,
+				QueryType: v3.QueryTypePromQL,
+				PromQueries: map[string]*v3.PromQuery{
+					"A": {
+						Query:    "http_calls_total{service_name=\"{{.service_name}}\", status_code=~\"{{.status_code}}\"}",
+						Disabled: false,
+					},
+				},
+			},
+			variables: map[string]interface{}{
+				"service_name": "route",
+				"status_code": []interface{}{
+					200,
+					505,
+				},
+			},
+			expectErr:     false,
+			expectedQuery: "http_calls_total{service_name=\"route\", status_code=~\"200|505\"}",
+		},
+		{
+			desc: "valid prom query with dashboard variables",
+			compositeQuery: v3.CompositeQuery{
+				PanelType: v3.PanelTypeGraph,
+				QueryType: v3.QueryTypePromQL,
+				PromQueries: map[string]*v3.PromQuery{
+					"A": {
+						Query:    "http_calls_total{service_name=\"{{.service_name}}\", quantity=~\"{{.quantity}}\"}",
+						Disabled: false,
+					},
+				},
+			},
+			variables: map[string]interface{}{
+				"service_name": "route",
+				"quantity": []interface{}{
+					4.5,
+					4.6,
+				},
+			},
+			expectErr:     false,
+			expectedQuery: "http_calls_total{service_name=\"route\", quantity=~\"4.5|4.6\"}",
+		},
+	}
+
+	for _, tc := range reqCases {
+		t.Run(tc.desc, func(t *testing.T) {
+
+			queryRangeParams := &v3.QueryRangeParamsV3{
+				Start:          time.Now().Add(-time.Hour).UnixMilli(),
+				End:            time.Now().UnixMilli(),
+				Step:           time.Minute.Microseconds(),
+				CompositeQuery: &tc.compositeQuery,
+				Variables:      tc.variables,
+			}
+
+			body := &bytes.Buffer{}
+			err := json.NewEncoder(body).Encode(queryRangeParams)
+			require.NoError(t, err)
+			req := httptest.NewRequest(http.MethodPost, "/api/v3/query_range", body)
+
+			parsedQueryRangeParams, apiErr := ParseQueryRangeParams(req)
+			if tc.expectErr {
+				require.Error(t, apiErr)
+				require.Contains(t, apiErr.Error(), tc.errMsg)
+			} else {
+				require.Nil(t, apiErr)
+				require.Equal(t, parsedQueryRangeParams.CompositeQuery.PromQueries["A"].Query, tc.expectedQuery)
+			}
+		})
+	}
+}