remove global name validation

expfmt/decode.go

@@ -29,7 +29,7 @@ import (
 
 // Decoder types decode an input stream into metric families.
 type Decoder interface {
-	Decode(*dto.MetricFamily) error
+	Decode(*dto.MetricFamily, model.ValidationScheme) error
 }
 
 // DecodeOptions contains options used by the Decoder and in sample extraction.
@@ -86,14 +86,14 @@ type protoDecoder struct {
 }
 
 // Decode implements the Decoder interface.
-func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
+func (d *protoDecoder) Decode(v *dto.MetricFamily, nameValidationScheme model.ValidationScheme) error {
 	opts := protodelim.UnmarshalOptions{
 		MaxSize: -1,
 	}
 	if err := opts.UnmarshalFrom(d.r, v); err != nil {
 		return err
 	}
-	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
+	if !model.IsValidMetricName(model.LabelValue(v.GetName()), nameValidationScheme) {
 		return fmt.Errorf("invalid metric name %q", v.GetName())
 	}
 	for _, m := range v.GetMetric() {
@@ -107,7 +107,7 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 			if !model.LabelValue(l.GetValue()).IsValid() {
 				return fmt.Errorf("invalid label value %q", l.GetValue())
 			}
-			if !model.LabelName(l.GetName()).IsValid() {
+			if !model.LabelName(l.GetName()).IsValid(nameValidationScheme) {
 				return fmt.Errorf("invalid label name %q", l.GetName())
 			}
 		}
@@ -123,7 +123,7 @@ type textDecoder struct {
 }
 
 // Decode implements the Decoder interface.
-func (d *textDecoder) Decode(v *dto.MetricFamily) error {
+func (d *textDecoder) Decode(v *dto.MetricFamily, _ model.ValidationScheme) error {
 	if d.err == nil {
 		// Read all metrics in one shot.
 		var p TextParser
@@ -156,8 +156,8 @@ type SampleDecoder struct {
 
 // Decode calls the Decode method of the wrapped Decoder and then extracts the
 // samples from the decoded MetricFamily into the provided model.Vector.
-func (sd *SampleDecoder) Decode(s *model.Vector) error {
-	err := sd.Dec.Decode(&sd.f)
+func (sd *SampleDecoder) Decode(s *model.Vector, nameValidationScheme model.ValidationScheme) error {
+	err := sd.Dec.Decode(&sd.f, nameValidationScheme)
 	if err != nil {
 		return err
 	}

expfmt/decode_test.go

@@ -88,7 +88,7 @@ mf2 4
 	var all model.Vector
 	for {
 		var smpls model.Vector
-		err := dec.Decode(&smpls)
+		err := dec.Decode(&smpls, model.UTF8Validation)
 		if err != nil && errors.Is(err, io.EOF) {
 			break
 		}
@@ -369,22 +369,20 @@ func TestProtoDecoder(t *testing.T) {
 
 		var all model.Vector
 		for {
-			model.NameValidationScheme = model.LegacyValidation //nolint:staticcheck
 			var smpls model.Vector
-			err := dec.Decode(&smpls)
+			err := dec.Decode(&smpls, model.LegacyValidation)
 			if err != nil && errors.Is(err, io.EOF) {
 				break
 			}
 			if scenario.legacyNameFail {
 				require.Errorf(t, err, "Expected error when decoding without UTF-8 support enabled but got none")
-				model.NameValidationScheme = model.UTF8Validation //nolint:staticcheck
 				dec = &SampleDecoder{
 					Dec: &protoDecoder{r: strings.NewReader(scenario.in)},
 					Opts: &DecodeOptions{
 						Timestamp: testTime,
 					},
 				}
-				err = dec.Decode(&smpls)
+				err = dec.Decode(&smpls, model.UTF8Validation)
 				if errors.Is(err, io.EOF) {
 					break
 				}
@@ -412,7 +410,7 @@ func TestProtoMultiMessageDecoder(t *testing.T) {
 	var metrics []*dto.MetricFamily
 	for {
 		var mf dto.MetricFamily
-		if err := decoder.Decode(&mf); err != nil {
+		if err := decoder.Decode(&mf, model.UTF8Validation); err != nil {
 			if errors.Is(err, io.EOF) {
 				break
 			}
@@ -560,7 +558,7 @@ func TestTextDecoderWithBufioReader(t *testing.T) {
 	dec := NewDecoder(r, FmtText)
 	for {
 		var mf dto.MetricFamily
-		if err := dec.Decode(&mf); err != nil {
+		if err := dec.Decode(&mf, model.UTF8Validation); err != nil {
 			if errors.Is(err, io.EOF) {
 				break
 			}

go.mod

@@ -36,3 +36,5 @@ require (
 )
 
 retract v0.50.0 // Critical bug in counter suffixes, please read issue https://github.com/prometheus/common/issues/605
+
+replace github.com/prometheus/client_golang => github.com/juliusmh/client_golang v1.22.1-0.20250701110037-ceb5803cbf1f

go.sum

@@ -15,8 +15,8 @@ github.com/jpillora/backoff v1.0.0 h1:uvFg412JmmHBHw7iwprIxkPMI+sGQ4kzOWsMeHnm2E
 github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
-github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
-github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
+github.com/juliusmh/client_golang v1.22.1-0.20250701110037-ceb5803cbf1f h1:UU3kYZyItj1WIp7nfjBrw+S9xjyEX1NbHgp1UP3Ov6U=
+github.com/juliusmh/client_golang v1.22.1-0.20250701110037-ceb5803cbf1f/go.mod h1:tF4MYJHY3axE4Wh1TgNU/klT0a4RUGthK8Chg9eU/sA=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
@@ -29,8 +29,6 @@ github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f h1:KUppIJq7/+
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v1.20.4 h1:Tgh3Yr67PaOv/uTqloMsCEdeuFTatm5zIq5+qNN23vI=
-github.com/prometheus/client_golang v1.20.4/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
 github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
 github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=

model/alert.go

@@ -88,20 +88,20 @@ func (a *Alert) StatusAt(ts time.Time) AlertStatus {
 }
 
 // Validate checks whether the alert data is inconsistent.
-func (a *Alert) Validate() error {
+func (a *Alert) Validate(nameValidationScheme ValidationScheme) error {
 	if a.StartsAt.IsZero() {
 		return errors.New("start time missing")
 	}
 	if !a.EndsAt.IsZero() && a.EndsAt.Before(a.StartsAt) {
 		return errors.New("start time must be before end time")
 	}
-	if err := a.Labels.Validate(); err != nil {
+	if err := a.Labels.Validate(nameValidationScheme); err != nil {
 		return fmt.Errorf("invalid label set: %w", err)
 	}
 	if len(a.Labels) == 0 {
 		return errors.New("at least one label pair required")
 	}
-	if err := a.Annotations.Validate(); err != nil {
+	if err := a.Annotations.Validate(nameValidationScheme); err != nil {
 		return fmt.Errorf("invalid annotations: %w", err)
 	}
 	return nil

model/alert_test.go

@@ -22,91 +22,97 @@ import (
 )
 
 func TestAlertValidate(t *testing.T) {
-	oldScheme := NameValidationScheme
-	NameValidationScheme = LegacyValidation
-	defer func() {
-		NameValidationScheme = oldScheme
-	}()
 	ts := time.Now()
 
 	cases := []struct {
-		alert *Alert
-		err   string
+		alert  *Alert
+		err    string
+		scheme ValidationScheme
 	}{
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b"},
 				StartsAt: ts,
 			},
+			scheme: LegacyValidation,
 		},
 		{
 			alert: &Alert{
 				Labels: LabelSet{"a": "b"},
 			},
-			err: "start time missing",
+			scheme: LegacyValidation,
+			err:    "start time missing",
 		},
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b"},
 				StartsAt: ts,
 				EndsAt:   ts,
 			},
+			scheme: LegacyValidation,
 		},
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b"},
 				StartsAt: ts,
 				EndsAt:   ts.Add(1 * time.Minute),
 			},
+			scheme: LegacyValidation,
 		},
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b"},
 				StartsAt: ts,
 				EndsAt:   ts.Add(-1 * time.Minute),
 			},
-			err: "start time must be before end time",
+			scheme: LegacyValidation,
+			err:    "start time must be before end time",
 		},
 		{
 			alert: &Alert{
 				StartsAt: ts,
 			},
-			err: "at least one label pair required",
+			scheme: LegacyValidation,
+			err:    "at least one label pair required",
 		},
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b", "!bad": "label"},
 				StartsAt: ts,
 			},
-			err: "invalid label set: invalid name",
+			scheme: LegacyValidation,
+			err:    "invalid label set: invalid name",
 		},
 		{
 			alert: &Alert{
 				Labels:   LabelSet{"a": "b", "bad": "\xfflabel"},
 				StartsAt: ts,
 			},
-			err: "invalid label set: invalid value",
+			scheme: LegacyValidation,
+			err:    "invalid label set: invalid value",
 		},
 		{
 			alert: &Alert{
 				Labels:      LabelSet{"a": "b"},
 				Annotations: LabelSet{"!bad": "label"},
 				StartsAt:    ts,
 			},
-			err: "invalid annotations: invalid name",
+			scheme: LegacyValidation,
+			err:    "invalid annotations: invalid name",
 		},
 		{
 			alert: &Alert{
 				Labels:      LabelSet{"a": "b"},
 				Annotations: LabelSet{"bad": "\xfflabel"},
 				StartsAt:    ts,
 			},
-			err: "invalid annotations: invalid value",
+			scheme: LegacyValidation,
+			err:    "invalid annotations: invalid value",
 		},
 	}
 
 	for i, c := range cases {
-		err := c.alert.Validate()
+		err := c.alert.Validate(c.scheme)
 		if err == nil {
 			if c.err == "" {
 				continue

model/labels.go

@@ -104,19 +104,18 @@ var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
 type LabelName string
 
 // IsValid returns true iff the name matches the pattern of LabelNameRE when
-// NameValidationScheme is set to LegacyValidation, or valid UTF-8 if
-// NameValidationScheme is set to UTF8Validation.
-func (ln LabelName) IsValid() bool {
+// scheme is LegacyValidation, or valid UTF-8 if it is UTF8Validation.
+func (ln LabelName) IsValid(scheme ValidationScheme) bool {
 	if len(ln) == 0 {
 		return false
 	}
-	switch NameValidationScheme {
+	switch scheme {
 	case LegacyValidation:
 		return ln.IsValidLegacy()
 	case UTF8Validation:
 		return utf8.ValidString(string(ln))
 	default:
-		panic(fmt.Sprintf("Invalid name validation scheme requested: %d", NameValidationScheme))
+		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", scheme.String()))
 	}
 }
 
@@ -137,25 +136,27 @@ func (ln LabelName) IsValidLegacy() bool {
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
+// Validation is done using UTF8Validation.
 func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	var s string
 	if err := unmarshal(&s); err != nil {
 		return err
 	}
-	if !LabelName(s).IsValid() {
+	if !LabelName(s).IsValid(UTF8Validation) {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)
 	return nil
 }
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
+// Validation is done using UTF8Validation.
 func (ln *LabelName) UnmarshalJSON(b []byte) error {
 	var s string
 	if err := json.Unmarshal(b, &s); err != nil {
 		return err
 	}
-	if !LabelName(s).IsValid() {
+	if !LabelName(s).IsValid(UTF8Validation) {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)

model/labels_test.go

@@ -144,15 +144,13 @@ func TestLabelNameIsValid(t *testing.T) {
 	}
 
 	for _, s := range scenarios {
-		NameValidationScheme = LegacyValidation
-		if s.ln.IsValid() != s.legacyValid {
+		if s.ln.IsValid(LegacyValidation) != s.legacyValid {
 			t.Errorf("Expected %v for %q using legacy IsValid method", s.legacyValid, s.ln)
 		}
 		if LabelNameRE.MatchString(string(s.ln)) != s.legacyValid {
 			t.Errorf("Expected %v for %q using legacy regexp match", s.legacyValid, s.ln)
 		}
-		NameValidationScheme = UTF8Validation
-		if s.ln.IsValid() != s.utf8Valid {
+		if s.ln.IsValid(UTF8Validation) != s.utf8Valid {
 			t.Errorf("Expected %v for %q using UTF-8 IsValid method", s.legacyValid, s.ln)
 		}
 	}

model/labelset.go

@@ -28,9 +28,9 @@ type LabelSet map[LabelName]LabelValue
 
 // Validate checks whether all names and values in the label set
 // are valid.
-func (ls LabelSet) Validate() error {
+func (ls LabelSet) Validate(nameValidationScheme ValidationScheme) error {
 	for ln, lv := range ls {
-		if !ln.IsValid() {
+		if !ln.IsValid(nameValidationScheme) {
 			return fmt.Errorf("invalid name %q", ln)
 		}
 		if !lv.IsValid() {
@@ -140,6 +140,7 @@ func (ls LabelSet) FastFingerprint() Fingerprint {
 }
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
+// Validates label names using UTF8Validation.
 func (l *LabelSet) UnmarshalJSON(b []byte) error {
 	var m map[LabelName]LabelValue
 	if err := json.Unmarshal(b, &m); err != nil {
@@ -149,7 +150,7 @@ func (l *LabelSet) UnmarshalJSON(b []byte) error {
 	// LabelName as a string and does not call its UnmarshalJSON method.
 	// Thus, we have to replicate the behavior here.
 	for ln := range m {
-		if !ln.IsValid() {
+		if !ln.IsValid(UTF8Validation) {
 			return fmt.Errorf("%q is not a valid label name", ln)
 		}
 	}

model/labelset_test.go

@@ -16,6 +16,8 @@ package model
 import (
 	"encoding/json"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestUnmarshalJSONLabelSet(t *testing.T) {
@@ -55,12 +57,10 @@ func TestUnmarshalJSONLabelSet(t *testing.T) {
 	}
 }`
 
-	NameValidationScheme = LegacyValidation
 	err = json.Unmarshal([]byte(invalidlabelSetJSON), &c)
-	expectedErr := `"1nvalid_23name" is not a valid label name`
-	if err == nil || err.Error() != expectedErr {
-		t.Errorf("expected an error with message '%s' to be thrown", expectedErr)
-	}
+	require.NoError(t, err)
+	err = c.LabelSet.Validate(LegacyValidation)
+	require.EqualError(t, err, `invalid name "1nvalid_23name"`)
 }
 
 func TestLabelSetClone(t *testing.T) {