fix(apiv3): Accept camelCase HTTP query params, keep snake_case as deprecated aliases (jaegertracing#8625)

## Summary

Part 2 of jaegertracing#8619.

- Moves all query param constants and `parseFindTracesQuery` into a new
`query_parser.go`
- Canonical param names are now camelCase (e.g. `query.serviceName`,
`startTime`, `spanKind`) matching proto3 JSON encoding convention used
by gRPC-gateway
- All previous snake_case names (`query.service_name`, `start_time`,
`span_kind`, etc.) are kept as deprecated fallbacks via a
`getQueryParam` helper that prefers the canonical name
- `query.num_traces` remains a deprecated alias for `query.searchDepth`
(on top of the snake_case alias `query.search_depth`)

No response body changes — the server already returns camelCase via
`jsonpb.Marshaler`.

## Test plan

- [ ] All existing tests pass
- [ ] New `TestHTTPGatewayFindTracesDeprecatedParams` verifies all
snake_case fallbacks for FindTraces
- [ ] `TestHTTPGatewayGetTrace` has canonical + deprecated subtests for
time window params
- [ ] `TestHTTPGatewayGetOperationsErrors` tests both `spanKind`
(canonical) and `span_kind` (deprecated)
- [ ] Error messages include the actual param name used (canonical or
deprecated), so clients get actionable feedback

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Signed-off-by: Yuri Shkuro <github@ysh.us>

Author: yurishkuro

cmd/jaeger/internal/extension/jaegerquery/internal/apiv3/gateway_test.go

@@ -131,7 +131,7 @@ func (gw *testGateway) runGatewayGetOperations(t *testing.T) {
 		On("GetOperations", matchContext, qp).
 		Return([]tracestore.Operation{{Name: "get_users", SpanKind: "server"}}, nil).Once()
 
-	body, statusCode := gw.execRequest(t, "/api/v3/operations?service=foo&span_kind=server")
+	body, statusCode := gw.execRequest(t, "/api/v3/operations?service=foo&spanKind=server")
 	require.Equal(t, http.StatusOK, statusCode)
 	body = gw.verifySnapshot(t, body)
 

cmd/jaeger/internal/extension/jaegerquery/internal/apiv3/http_gateway.go

@@ -8,13 +8,11 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"net/url"
 	"strconv"
 	"time"
 
 	"github.com/gogo/protobuf/jsonpb"
 	"github.com/gogo/protobuf/proto"
-	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/ptrace"
 	"go.opentelemetry.io/otel/trace"
 	"go.uber.org/zap"
@@ -29,29 +27,6 @@ import (
 	"github.com/jaegertracing/jaeger/internal/storage/v2/v1adapter"
 )
 
-const (
-	paramTraceID       = "trace_id" // get trace by ID
-	paramStartTime     = "start_time"
-	paramEndTime       = "end_time"
-	paramRawTraces     = "raw_traces"
-	paramServiceName   = "query.service_name" // find traces
-	paramOperationName = "query.operation_name"
-	paramTimeMin       = "query.start_time_min"
-	paramTimeMax       = "query.start_time_max"
-	// paramSearchDepth is the canonical name matching the proto field and the future gRPC-gateway generated binding.
-	paramSearchDepth = "query.search_depth"
-	// paramNumTraces is a deprecated alias for paramSearchDepth kept for backwards compatibility.
-	paramNumTraces      = "query.num_traces"
-	paramDurationMin    = "query.duration_min"
-	paramDurationMax    = "query.duration_max"
-	paramQueryRawTraces = "query.raw_traces"
-
-	routeGetTrace      = "/api/v3/traces/{" + paramTraceID + "}"
-	routeFindTraces    = "/api/v3/traces"
-	routeGetServices   = "/api/v3/services"
-	routeGetOperations = "/api/v3/operations"
-)
-
 // HTTPGateway exposes APIv3 HTTP endpoints.
 type HTTPGateway struct {
 	QueryService *querysvc.QueryService
@@ -166,26 +141,24 @@ func (h *HTTPGateway) getTrace(w http.ResponseWriter, r *http.Request) {
 			},
 		},
 	}
-	http_query := r.URL.Query()
-	startTime := http_query.Get(paramStartTime)
-	if startTime != "" {
+	q := r.URL.Query()
+	if startTime, paramName := getQueryParam(q, paramStartTime, paramStartTimeDeprecated); startTime != "" {
 		timeParsed, err := time.Parse(time.RFC3339Nano, startTime)
-		if h.tryParamError(w, err, paramStartTime) {
+		if h.tryParamError(w, err, paramName) {
 			return
 		}
 		request.TraceIDs[0].Start = timeParsed.UTC()
 	}
-	endTime := http_query.Get(paramEndTime)
-	if endTime != "" {
+	if endTime, paramName := getQueryParam(q, paramEndTime, paramEndTimeDeprecated); endTime != "" {
 		timeParsed, err := time.Parse(time.RFC3339Nano, endTime)
-		if h.tryParamError(w, err, paramEndTime) {
+		if h.tryParamError(w, err, paramName) {
 			return
 		}
 		request.TraceIDs[0].End = timeParsed.UTC()
 	}
-	if r := http_query.Get(paramRawTraces); r != "" {
-		rawTraces, err := strconv.ParseBool(r)
-		if h.tryParamError(w, err, paramRawTraces) {
+	if rawStr, paramName := getQueryParam(q, paramRawTraces, paramRawTracesDeprecated); rawStr != "" {
+		rawTraces, err := strconv.ParseBool(rawStr)
+		if h.tryParamError(w, err, paramName) {
 			return
 		}
 		request.RawTraces = rawTraces
@@ -206,71 +179,6 @@ func (h *HTTPGateway) findTraces(w http.ResponseWriter, r *http.Request) {
 	h.returnTraces(traces, err, w)
 }
 
-func (h *HTTPGateway) parseFindTracesQuery(q url.Values, w http.ResponseWriter) (*querysvc.TraceQueryParams, bool) {
-	queryParams := &querysvc.TraceQueryParams{
-		TraceQueryParams: tracestore.TraceQueryParams{
-			ServiceName:   q.Get(paramServiceName),
-			OperationName: q.Get(paramOperationName),
-			Attributes:    pcommon.NewMap(), // most curiously not supported by grpc-gateway
-		},
-	}
-
-	timeMin := q.Get(paramTimeMin)
-	timeMax := q.Get(paramTimeMax)
-	if timeMin == "" || timeMax == "" {
-		err := fmt.Errorf("%s and %s are required", paramTimeMin, paramTimeMax)
-		h.tryHandleError(w, err, http.StatusBadRequest)
-		return nil, true
-	}
-	timeMinParsed, err := time.Parse(time.RFC3339Nano, timeMin)
-	if h.tryParamError(w, err, paramTimeMin) {
-		return nil, true
-	}
-	timeMaxParsed, err := time.Parse(time.RFC3339Nano, timeMax)
-	if h.tryParamError(w, err, paramTimeMax) {
-		return nil, true
-	}
-	queryParams.StartTimeMin = timeMinParsed
-	queryParams.StartTimeMax = timeMaxParsed
-
-	searchDepthParam := paramSearchDepth
-	n := q.Get(paramSearchDepth)
-	if n == "" {
-		n = q.Get(paramNumTraces)
-		searchDepthParam = paramNumTraces
-	}
-	if n != "" {
-		searchDepth, err := strconv.Atoi(n)
-		if h.tryParamError(w, err, searchDepthParam) {
-			return nil, true
-		}
-		queryParams.SearchDepth = searchDepth
-	}
-
-	if d := q.Get(paramDurationMin); d != "" {
-		dur, err := time.ParseDuration(d)
-		if h.tryParamError(w, err, paramDurationMin) {
-			return nil, true
-		}
-		queryParams.DurationMin = dur
-	}
-	if d := q.Get(paramDurationMax); d != "" {
-		dur, err := time.ParseDuration(d)
-		if h.tryParamError(w, err, paramDurationMax) {
-			return nil, true
-		}
-		queryParams.DurationMax = dur
-	}
-	if r := q.Get(paramQueryRawTraces); r != "" {
-		rawTraces, err := strconv.ParseBool(r)
-		if h.tryParamError(w, err, paramQueryRawTraces) {
-			return nil, true
-		}
-		queryParams.RawTraces = rawTraces
-	}
-	return queryParams, false
-}
-
 func (h *HTTPGateway) getServices(w http.ResponseWriter, r *http.Request) {
 	services, err := h.QueryService.GetServices(r.Context())
 	if h.tryHandleError(w, err, http.StatusInternalServerError) {
@@ -285,10 +193,11 @@ func (h *HTTPGateway) getServices(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *HTTPGateway) getOperations(w http.ResponseWriter, r *http.Request) {
-	query := r.URL.Query()
+	q := r.URL.Query()
+	spanKind, _ := getQueryParam(q, paramSpanKind, paramSpanKindDeprecated)
 	queryParams := tracestore.OperationQueryParams{
-		ServiceName: query.Get("service"),
-		SpanKind:    query.Get("span_kind"),
+		ServiceName: q.Get("service"),
+		SpanKind:    spanKind,
 	}
 	operations, err := h.QueryService.GetOperations(r.Context(), queryParams)
 	if h.tryHandleError(w, err, http.StatusInternalServerError) {