From e176cf2837a853b7b79b06160d373b67f066f566 Mon Sep 17 00:00:00 2001
From: Joel Verezhak <jverezhak@open-systems.com>
Date: Fri, 11 Jul 2025 23:32:55 +0200
Subject: [PATCH] fix: querier external labels match relabel config

Signed-off-by: Joel Verezhak <jverezhak@open-systems.com>
---
 cmd/thanos/query.go |  1 +
 pkg/api/query/v1.go | 20 +++++++++++++++++++-
 pkg/store/proxy.go  | 33 ++++++++++++++++++++++++++++++---
 3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/cmd/thanos/query.go b/cmd/thanos/query.go
index 20379f0611e..f7fd5e500ae 100644
--- a/cmd/thanos/query.go
+++ b/cmd/thanos/query.go
@@ -553,6 +553,7 @@ func runQuery(
 			tenantCertField,
 			enforceTenancy,
 			tenantLabel,
+			tsdbSelector,
 		)
 
 		api.Register(router.WithPrefix("/api/v1"), tracer, logger, ins, logMiddleware)
diff --git a/pkg/api/query/v1.go b/pkg/api/query/v1.go
index 18fcf49f80e..b9f4de691c7 100644
--- a/pkg/api/query/v1.go
+++ b/pkg/api/query/v1.go
@@ -111,6 +111,7 @@ type QueryAPI struct {
 
 	replicaLabels  []string
 	endpointStatus func() []query.EndpointStatus
+	tsdbSelector   *store.TSDBSelector
 
 	defaultRangeQueryStep                  time.Duration
 	defaultInstantQueryMaxSourceResolution time.Duration
@@ -160,6 +161,7 @@ func NewQueryAPI(
 	tenantCertField string,
 	enforceTenancy bool,
 	tenantLabel string,
+	tsdbSelector *store.TSDBSelector,
 ) *QueryAPI {
 	if statsAggregatorFactory == nil {
 		statsAggregatorFactory = &store.NoopSeriesStatsAggregatorFactory{}
@@ -195,6 +197,7 @@ func NewQueryAPI(
 		tenantCertField:                        tenantCertField,
 		enforceTenancy:                         enforceTenancy,
 		tenantLabel:                            tenantLabel,
+		tsdbSelector:                           tsdbSelector,
 
 		queryRangeHist: promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
 			Name:    "thanos_query_range_requested_timespan_duration_seconds",
@@ -1296,7 +1299,22 @@ func (qapi *QueryAPI) stores(_ *http.Request) (interface{}, []error, *api.ApiErr
 		if status.ComponentType == nil {
 			continue
 		}
-		statuses[status.ComponentType.String()] = append(statuses[status.ComponentType.String()], status)
+		
+		// Apply TSDBSelector filtering to LabelSets if selector is configured
+		filteredStatus := status
+		if qapi.tsdbSelector != nil && len(status.LabelSets) > 0 {
+			matches, filteredLabelSets := qapi.tsdbSelector.MatchLabelSets(status.LabelSets...)
+			if !matches {
+				// Skip this endpoint if it doesn't match the TSDBSelector
+				continue
+			}
+			if filteredLabelSets != nil {
+				// Use the filtered label sets if available
+				filteredStatus.LabelSets = filteredLabelSets
+			}
+		}
+		
+		statuses[status.ComponentType.String()] = append(statuses[status.ComponentType.String()], filteredStatus)
 	}
 	return statuses, nil, nil, func() {}
 }
diff --git a/pkg/store/proxy.go b/pkg/store/proxy.go
index 2c63b6c099a..e4a9ffb8ad2 100644
--- a/pkg/store/proxy.go
+++ b/pkg/store/proxy.go
@@ -202,7 +202,22 @@ func (s *ProxyStore) LabelSet() []labelpb.ZLabelSet {
 
 	mergedLabelSets := make(map[uint64]labelpb.ZLabelSet, len(stores))
 	for _, st := range stores {
-		for _, lset := range st.LabelSets() {
+		// Apply TSDBSelector filtering to each individual label set
+		matches, filteredLabelSets := s.tsdbSelector.MatchLabelSets(st.LabelSets()...)
+		
+		if !matches {
+			continue
+		}
+		
+		// Use the filtered label sets if available, otherwise use original
+		var labelSetsToProcess []labels.Labels
+		if filteredLabelSets != nil {
+			labelSetsToProcess = filteredLabelSets
+		} else {
+			labelSetsToProcess = st.LabelSets()
+		}
+		
+		for _, lset := range labelSetsToProcess {
 			mergedLabelSet := labelpb.ExtendSortedLabels(lset, s.selectorLabels)
 			mergedLabelSets[mergedLabelSet.Hash()] = labelpb.ZLabelSet{Labels: labelpb.ZLabelsFromPromLabels(mergedLabelSet)}
 		}
@@ -232,8 +247,15 @@ func (s *ProxyStore) TimeRange() (int64, int64) {
 	}
 
 	var minTime, maxTime int64 = math.MaxInt64, math.MinInt64
-	for _, s := range stores {
-		storeMinTime, storeMaxTime := s.TimeRange()
+	hasMatchingStores := false
+	for _, st := range stores {
+		// Apply TSDBSelector filtering to match what's used in TSDBInfos() and actual queries
+		matches, _ := s.tsdbSelector.MatchLabelSets(st.LabelSets()...)
+		if !matches {
+			continue
+		}
+		hasMatchingStores = true
+		storeMinTime, storeMaxTime := st.TimeRange()
 		if storeMinTime < minTime {
 			minTime = storeMinTime
 		}
@@ -242,6 +264,11 @@ func (s *ProxyStore) TimeRange() (int64, int64) {
 		}
 	}
 
+	// If no stores match the selector, return the full range as fallback
+	if !hasMatchingStores {
+		return math.MinInt64, math.MaxInt64
+	}
+
 	return minTime, maxTime
 }