Make label name character set validation optional

pkg/distributor/distributor.go

@@ -155,9 +155,9 @@ type Config struct {
 	// for testing
 	ingesterClientFactory ring_client.PoolFactory `yaml:"-"`
 
-	// when true the distributor does not validate labels at ingest time, Cortex doesn't directly use
+	// when true the distributor does not validate the label name, Cortex doesn't directly use
 	// this (and should never use it) but this feature is used by other projects built on top of it
-	SkipLabelValidation bool `yaml:"-"`
+	SkipLabelNameValidation bool `yaml:"-"`
 }
 
 // RegisterFlags adds the flags required to config this to the given FlagSet
@@ -336,10 +336,8 @@ func (d *Distributor) checkSample(ctx context.Context, userID, cluster, replica
 // Returns the validated series with it's labels/samples, and any error.
 func (d *Distributor) validateSeries(ts ingester_client.PreallocTimeseries, userID string) (client.PreallocTimeseries, error) {
 	labelsHistogram.Observe(float64(len(ts.Labels)))
-	if !d.cfg.SkipLabelValidation {
-		if err := validation.ValidateLabels(d.limits, userID, ts.Labels); err != nil {
-			return emptyPreallocSeries, err
-		}
+	if err := validation.ValidateLabels(d.limits, userID, ts.Labels, d.cfg.SkipLabelNameValidation); err != nil {
+		return emptyPreallocSeries, err
 	}
 
 	metricName, _ := extract.MetricNameFromLabelAdapters(ts.Labels)

pkg/util/validation/validate.go

@@ -112,9 +112,9 @@ type LabelValidationConfig interface {
 }
 
 // ValidateLabels returns an err if the labels are invalid.
-func ValidateLabels(cfg LabelValidationConfig, userID string, ls []client.LabelAdapter) error {
-	metricName, err := extract.MetricNameFromLabelAdapters(ls)
+func ValidateLabels(cfg LabelValidationConfig, userID string, ls []client.LabelAdapter, skipLabelNameValidation bool) error {
 	if cfg.EnforceMetricName(userID) {
+		metricName, err := extract.MetricNameFromLabelAdapters(ls)
 		if err != nil {
 			DiscardedSamples.WithLabelValues(missingMetricName, userID).Inc()
 			return httpgrpc.Errorf(http.StatusBadRequest, errMissingMetricName)
@@ -139,7 +139,7 @@ func ValidateLabels(cfg LabelValidationConfig, userID string, ls []client.LabelA
 		var errTemplate string
 		var reason string
 		var cause interface{}
-		if !model.LabelName(l.Name).IsValid() {
+		if !skipLabelNameValidation && !model.LabelName(l.Name).IsValid() {
 			reason = invalidLabel
 			errTemplate = errInvalidLabel
 			cause = l.Name

pkg/util/validation/validate_test.go

@@ -57,40 +57,53 @@ func TestValidateLabels(t *testing.T) {
 	cfg.enforceMetricName = true
 
 	for _, c := range []struct {
-		metric model.Metric
-		err    error
+		metric                  model.Metric
+		skipLabelNameValidation bool
+		err                     error
 	}{
 		{
 			map[model.LabelName]model.LabelValue{},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errMissingMetricName),
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: " "},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errInvalidMetricName, " "),
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "valid", "foo ": "bar"},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errInvalidLabel, "foo ", `valid{foo ="bar"}`),
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "valid"},
+			false,
 			nil,
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "badLabelName", "this_is_a_really_really_long_name_that_should_cause_an_error": "test_value_please_ignore"},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errLabelNameTooLong, "this_is_a_really_really_long_name_that_should_cause_an_error", `badLabelName{this_is_a_really_really_long_name_that_should_cause_an_error="test_value_please_ignore"}`),
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "badLabelValue", "much_shorter_name": "test_value_please_ignore_no_really_nothing_to_see_here"},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errLabelValueTooLong, "test_value_please_ignore_no_really_nothing_to_see_here", `badLabelValue{much_shorter_name="test_value_please_ignore_no_really_nothing_to_see_here"}`),
 		},
 		{
 			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "foo", "bar": "baz", "blip": "blop"},
+			false,
 			httpgrpc.Errorf(http.StatusBadRequest, errTooManyLabels, `foo{bar="baz", blip="blop"}`, 3, 2),
 		},
+		{
+			map[model.LabelName]model.LabelValue{model.MetricNameLabel: "foo", "invalid%label&name": "bar"},
+			true,
+			nil,
+		},
 	} {
 
-		err := ValidateLabels(cfg, userID, client.FromMetricsToLabelAdapters(c.metric))
+		err := ValidateLabels(cfg, userID, client.FromMetricsToLabelAdapters(c.metric), c.skipLabelNameValidation)
 		assert.Equal(t, c.err, err, "wrong error")
 	}
 }
@@ -151,7 +164,7 @@ func TestValidateLabelOrder(t *testing.T) {
 		{Name: model.MetricNameLabel, Value: "m"},
 		{Name: "b", Value: "b"},
 		{Name: "a", Value: "a"},
-	})
+	}, false)
 	assert.Equal(t, httpgrpc.Errorf(http.StatusBadRequest, errLabelsNotSorted, "a", `m{b="b", a="a"}`), err)
 }
 
@@ -166,13 +179,13 @@ func TestValidateLabelDuplication(t *testing.T) {
 	err := ValidateLabels(cfg, userID, []client.LabelAdapter{
 		{Name: model.MetricNameLabel, Value: "a"},
 		{Name: model.MetricNameLabel, Value: "b"},
-	})
+	}, false)
 	assert.Equal(t, httpgrpc.Errorf(http.StatusBadRequest, errDuplicateLabelName, "__name__", `a{__name__="b"}`), err)
 
 	err = ValidateLabels(cfg, userID, []client.LabelAdapter{
 		{Name: model.MetricNameLabel, Value: "a"},
 		{Name: "a", Value: "a"},
 		{Name: "a", Value: "a"},
-	})
+	}, false)
 	assert.Equal(t, httpgrpc.Errorf(http.StatusBadRequest, errDuplicateLabelName, "a", `a{a="a", a="a"}`), err)
 }