Move pkg/normalizer to collector (jaegertracing#6877)

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## Which problem is this PR solving?
- part of jaegertracing#6869

## Description of the changes
- inline the `/pkg/normalizer `package into the metrics.go file where
it's used.

## How was this change tested?
-

## Checklist
- [ ] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [ ] I have signed all commits
- [ ] I have added unit tests for the new functionality
- [ ] 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: danish9039 <[email protected]>
Signed-off-by: Yuri Shkuro <[email protected]>
Co-authored-by: Yuri Shkuro <[email protected]>
Signed-off-by: amol-verma-allen <[email protected]>

Author: 2 people

cmd/collector/app/metrics.go

@@ -14,7 +14,6 @@ import (
 	"github.com/jaegertracing/jaeger-idl/model/v1"
 	"github.com/jaegertracing/jaeger/cmd/collector/app/processor"
 	"github.com/jaegertracing/jaeger/pkg/metrics"
-	"github.com/jaegertracing/jaeger/pkg/normalizer"
 	"github.com/jaegertracing/jaeger/pkg/otelsemconv"
 )
 
@@ -281,7 +280,7 @@ func (m metricsBySvc) countTracesByServiceName(serviceName string, isDebug bool,
 // an alert should be raised to investigate what's causing so many unique
 // service names.
 func (m *traceCountsBySvc) countByServiceName(serviceName string, isDebug bool, samplerType model.SamplerType) {
-	serviceName = normalizer.ServiceName(serviceName)
+	serviceName = normalizeServiceName(serviceName)
 	counts := m.counts
 	if isDebug {
 		counts = m.debugCounts
@@ -312,6 +311,7 @@ func (m *traceCountsBySvc) countByServiceName(serviceName string, isDebug bool,
 		}
 		counter = counts[otherServicesSampler]
 	}
+
 	m.lock.Unlock()
 	counter.Inc(1)
 }
@@ -327,7 +327,7 @@ func (m *traceCountsBySvc) countByServiceName(serviceName string, isDebug bool,
 // an alert should be raised to investigate what's causing so many unique
 // service names.
 func (m *spanCountsBySvc) countByServiceName(serviceName string, isDebug bool) {
-	serviceName = normalizer.ServiceName(serviceName)
+	serviceName = normalizeServiceName(serviceName)
 	counts := m.counts
 	if isDebug {
 		counts = m.debugCounts

pkg/normalizer/service_name.go renamed to cmd/collector/app/normalize.go

@@ -2,14 +2,14 @@
 // Copyright (c) 2017 Uber Technologies, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-package normalizer
+package app
 
 import (
 	"strings"
 )
 
-// ServiceName converts service name to a lowercase string that is safe to use in metrics
-func ServiceName(serviceName string) string {
+// normalizeServiceName converts service name to a string that is safe to use in metrics
+func normalizeServiceName(serviceName string) string {
 	return serviceNameReplacer.Replace(serviceName)
 }
 

cmd/collector/app/normalize_test.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2025 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package app
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNormalizeServiceName(t *testing.T) {
+	assert.Equal(t, "abc", normalizeServiceName("ABC"), "lower case conversion")
+	assert.Equal(t, "a_b_c__", normalizeServiceName("a&b%c/:"), "disallowed runes to underscore")
+	assert.Equal(t, "a_z_0123456789.", normalizeServiceName("A_Z_0123456789."), "allowed runes")
+}