[ES] Add feature to stop Legacy Trace IDs handling in SpanReader (jaegertracing#6848)

## Which problem is this PR solving?
Fixes a part of jaegertracing#6458

## Description of the changes
- As discussed in the comment
jaegertracing#6845 (comment),
legacy trace id is moved to feature gate

## How was this change tested?
- Unit and Integration tests

## Checklist
- [x] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [x] I have signed all commits
- [x] I have added unit tests for the new functionality
- [x] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `npm run lint` and `npm run test`

---------

Signed-off-by: Manik2708 <[email protected]>
Signed-off-by: amol-verma-allen <[email protected]>

Author: Manik2708

cmd/collector/main.go

@@ -19,6 +19,7 @@ import (
 	"github.com/jaegertracing/jaeger/cmd/collector/app/flags"
 	"github.com/jaegertracing/jaeger/cmd/internal/docs"
 	"github.com/jaegertracing/jaeger/cmd/internal/env"
+	"github.com/jaegertracing/jaeger/cmd/internal/featuregate"
 	cmdFlags "github.com/jaegertracing/jaeger/cmd/internal/flags"
 	"github.com/jaegertracing/jaeger/cmd/internal/printconfig"
 	"github.com/jaegertracing/jaeger/cmd/internal/status"
@@ -139,6 +140,7 @@ func main() {
 	command.AddCommand(docs.Command(v))
 	command.AddCommand(status.Command(v, ports.CollectorAdminHTTP))
 	command.AddCommand(printconfig.Command(v))
+	command.AddCommand(featuregate.Command())
 
 	config.AddFlags(
 		v,

cmd/es-index-cleaner/app/flags.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/spf13/viper"
 	"go.opentelemetry.io/collector/config/configtls"
+	"go.opentelemetry.io/collector/featuregate"
 
 	"github.com/jaegertracing/jaeger/pkg/config/tlscfg"
 )
@@ -47,6 +48,7 @@ func (*Config) AddFlags(flags *flag.FlagSet) {
 	flags.String(username, "", "The username required by storage")
 	flags.String(password, "", "The password required by storage")
 	tlsFlagsCfg.AddFlags(flags)
+	featuregate.GlobalRegistry().RegisterFlags(flags)
 }
 
 // InitFromViper initializes config from viper.Viper.

cmd/es-index-cleaner/main.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	"encoding/base64"
 	"errors"
-	"flag"
 	"fmt"
 	"log"
 	"net/http"
@@ -35,9 +34,6 @@ func init() {
 		featuregate.WithRegisterDescription("Controls whether the indices will be deleted relative to the current time or tomorrow midnight."),
 		featuregate.WithRegisterReferenceURL("https://github.com/jaegertracing/jaeger/issues/6236"),
 	)
-	featureGateFlagSet := flag.NewFlagSet("feature-gates", flag.ExitOnError)
-	featuregate.GlobalRegistry().RegisterFlags(featureGateFlagSet)
-	pflag.CommandLine.AddGoFlagSet(featureGateFlagSet)
 }
 
 func main() {

cmd/ingester/main.go

@@ -18,6 +18,7 @@ import (
 	"github.com/jaegertracing/jaeger/cmd/ingester/app/builder"
 	"github.com/jaegertracing/jaeger/cmd/internal/docs"
 	"github.com/jaegertracing/jaeger/cmd/internal/env"
+	"github.com/jaegertracing/jaeger/cmd/internal/featuregate"
 	"github.com/jaegertracing/jaeger/cmd/internal/flags"
 	"github.com/jaegertracing/jaeger/cmd/internal/printconfig"
 	"github.com/jaegertracing/jaeger/cmd/internal/status"
@@ -96,6 +97,7 @@ func main() {
 	command.AddCommand(docs.Command(v))
 	command.AddCommand(status.Command(v, ports.IngesterAdminHTTP))
 	command.AddCommand(printconfig.Command(v))
+	command.AddCommand(featuregate.Command())
 
 	config.AddFlags(
 		v,

cmd/internal/featuregate/command.go

@@ -0,0 +1,27 @@
+// Copyright (c) 2025 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package featuregate
+
+import (
+	"github.com/spf13/cobra"
+	"go.opentelemetry.io/collector/otelcol"
+)
+
+func Command() *cobra.Command {
+	return command(func() *cobra.Command {
+		settings := otelcol.CollectorSettings{}
+		return otelcol.NewCommand(settings)
+	})
+}
+
+func command(otelCmdFn func() *cobra.Command) *cobra.Command {
+	otelCmd := otelCmdFn()
+	for _, cmd := range otelCmd.Commands() {
+		if cmd.Name() == "featuregate" {
+			otelCmd.RemoveCommand(cmd)
+			return cmd
+		}
+	}
+	panic("could not find 'featuregate' command")
+}

cmd/internal/featuregate/command_test.go

@@ -0,0 +1,24 @@
+// Copyright (c) 2025 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package featuregate
+
+import (
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCommand(t *testing.T) {
+	cmd := Command()
+	assert.Equal(t, "featuregate [feature-id]", cmd.Use)
+}
+
+func TestCommand_Panic(t *testing.T) {
+	assert.PanicsWithValue(t, "could not find 'featuregate' command", func() {
+		command(func() *cobra.Command {
+			return &cobra.Command{}
+		})
+	})
+}

cmd/internal/featuregate/package_test.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2025 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package featuregate
+
+import (
+	"testing"
+
+	"github.com/jaegertracing/jaeger/internal/testutils"
+)
+
+func TestMain(m *testing.M) {
+	testutils.VerifyGoLeaks(m)
+}

cmd/internal/flags/service.go

@@ -12,6 +12,7 @@ import (
 	"syscall"
 
 	"github.com/spf13/viper"
+	"go.opentelemetry.io/collector/featuregate"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapgrpc"
 	"google.golang.org/grpc/grpclog"
@@ -87,6 +88,7 @@ func (s *Service) AddFlags(flagSet *flag.FlagSet) {
 	}
 	metricsbuilder.AddFlags(flagSet)
 	s.Admin.AddFlags(flagSet)
+	featuregate.GlobalRegistry().RegisterFlags(flagSet)
 }
 
 // Start bootstraps the service and starts the admin server.

cmd/query/main.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/jaegertracing/jaeger/cmd/internal/docs"
 	"github.com/jaegertracing/jaeger/cmd/internal/env"
+	"github.com/jaegertracing/jaeger/cmd/internal/featuregate"
 	"github.com/jaegertracing/jaeger/cmd/internal/flags"
 	"github.com/jaegertracing/jaeger/cmd/internal/printconfig"
 	"github.com/jaegertracing/jaeger/cmd/internal/status"
@@ -161,6 +162,7 @@ func main() {
 	command.AddCommand(docs.Command(v))
 	command.AddCommand(status.Command(v, ports.QueryAdminHTTP))
 	command.AddCommand(printconfig.Command(v))
+	command.AddCommand(featuregate.Command())
 
 	config.AddFlags(
 		v,

cmd/remote-storage/main.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/jaegertracing/jaeger/cmd/internal/docs"
 	"github.com/jaegertracing/jaeger/cmd/internal/env"
+	"github.com/jaegertracing/jaeger/cmd/internal/featuregate"
 	"github.com/jaegertracing/jaeger/cmd/internal/flags"
 	"github.com/jaegertracing/jaeger/cmd/internal/printconfig"
 	"github.com/jaegertracing/jaeger/cmd/internal/status"
@@ -101,6 +102,7 @@ func main() {
 	command.AddCommand(docs.Command(v))
 	command.AddCommand(status.Command(v, ports.QueryAdminHTTP))
 	command.AddCommand(printconfig.Command(v))
+	command.AddCommand(featuregate.Command())
 
 	config.AddFlags(
 		v,