Receiver: Fix labels debug logging in writer (#5642)

* Fix labels debug logging

Signed-off-by: Matej Gera <matejgera@gmail.com>

* Update CHANGELOG

Signed-off-by: Matej Gera <matejgera@gmail.com>

Signed-off-by: Matej Gera <matejgera@gmail.com>

CHANGELOG.md

@@ -17,6 +17,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#5534](https://github.com/thanos-io/thanos/pull/5534) Query: Set struct return by query api alerts same as prometheus api.
 - [#5554](https://github.com/thanos-io/thanos/pull/5554) Query/Receiver: Fix querying exemplars from multi-tenant receivers.
 - [#5583](https://github.com/thanos-io/thanos/pull/5583) Query: fix data race between Respond() and query/queryRange functions. Fixes [#5410](https://github.com/thanos-io/thanos/pull/5410).
+- [#5642](https://github.com/thanos-io/thanos/pull/5642) Receive: Log labels correctly in writer debug messages.
 
 ### Added
 

pkg/receive/writer.go

@@ -78,16 +78,17 @@ func (r *Writer) Write(ctx context.Context, tenantID string, wreq *prompb.WriteR
 		// Check if time series labels are valid. If not, skip the time series
 		// and report the error.
 		if err := labelpb.ValidateLabels(t.Labels); err != nil {
+			lset := &labelpb.ZLabelSet{Labels: t.Labels}
 			switch err {
 			case labelpb.ErrOutOfOrderLabels:
 				numLabelsOutOfOrder++
-				level.Debug(tLogger).Log("msg", "Out of order labels in the label set", "lset", t.Labels)
+				level.Debug(tLogger).Log("msg", "Out of order labels in the label set", "lset", lset.String())
 			case labelpb.ErrDuplicateLabels:
 				numLabelsDuplicates++
-				level.Debug(tLogger).Log("msg", "Duplicate labels in the label set", "lset", t.Labels)
+				level.Debug(tLogger).Log("msg", "Duplicate labels in the label set", "lset", lset.String())
 			case labelpb.ErrEmptyLabels:
 				numLabelsEmpty++
-				level.Debug(tLogger).Log("msg", "Labels with empty name in the label set", "lset", t.Labels)
+				level.Debug(tLogger).Log("msg", "Labels with empty name in the label set", "lset", lset.String())
 			default:
 				level.Debug(tLogger).Log("msg", "Error validating labels", "err", err)
 			}