Store: fix prometheus store label values for matches on external labels

External Labels should also be tested for matches against the matchers. Signed-off-by: Michael Hoffmann <mhoffm@posteo.de>
thanos-io · Oct 18, 2023 · cfca276 · cfca276
1 parent e4b579f
commit cfca276
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Showing 3 changed files with 13 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 ### Fixed
 
 - [#6802](https://github.com/thanos-io/thanos/pull/6802) Receive: head series limiter should not run if no head series limit is set.
+- [#6816](https://github.com/thanos-io/thanos/pull/6816) Store: fix prometheus store label values matches for external labels
 - [#6817](https://github.com/thanos-io/thanos/pull/6817) Store Gateway: fix `matchersToPostingGroups` label values variable got shadowed bug.
 
 ### Added

diff --git a/pkg/store/acceptance_test.go b/pkg/store/acceptance_test.go
@@ -184,6 +184,13 @@ func testStoreAPIsAcceptance(t *testing.T, startStore func(t *testing.T, extLset
 					matchers: []storepb.LabelMatcher{{Type: storepb.LabelMatcher_EQ, Name: "bar", Value: "different"}},
 				},
 				// Matchers on external labels.
+				{
+					start:          timestamp.FromTime(minTime),
+					end:            timestamp.FromTime(maxTime),
+					label:          "region",
+					expectedValues: []string(nil),
+					matchers:       []storepb.LabelMatcher{{Type: storepb.LabelMatcher_EQ, Name: "region", Value: "eu-east"}},
+				},
 				{
 					start:          timestamp.FromTime(minTime),
 					end:            timestamp.FromTime(maxTime),

diff --git a/pkg/store/prometheus.go b/pkg/store/prometheus.go
@@ -699,11 +699,6 @@ func (p *PrometheusStore) LabelValues(ctx context.Context, r *storepb.LabelValue
 
 	extLset := p.externalLabelsFn()
 
-	// First check for matching external label which has priority.
-	if l := extLset.Get(r.Label); l != "" {
-		return &storepb.LabelValuesResponse{Values: []string{l}}, nil
-	}
-
 	match, matchers, err := matchesExternalLabels(r.Matchers, extLset)
 	if err != nil {
 		return nil, status.Error(codes.InvalidArgument, err.Error())
@@ -712,6 +707,11 @@ func (p *PrometheusStore) LabelValues(ctx context.Context, r *storepb.LabelValue
 		return &storepb.LabelValuesResponse{Values: nil}, nil
 	}
 
+	// First check for matching external label which has priority.
+	if l := extLset.Get(r.Label); l != "" {
+		return &storepb.LabelValuesResponse{Values: []string{l}}, nil
+	}
+
 	var (
 		sers []map[string]string
 		vals []string