store: fix misc label_value issues related to external labels (#6879)

Signed-off-by: Michael Hoffmann <[email protected]>
thanos-io · Dec 5, 2023 · e578b1f · e578b1f
1 parent 28407d6
commit e578b1f
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Showing 3 changed files with 19 additions and 2 deletions.
diff --git a/pkg/store/acceptance_test.go b/pkg/store/acceptance_test.go
@@ -185,6 +185,13 @@ 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: "__name__", Value: "nonexistent"}},
+				},
 				{
 					start:          timestamp.FromTime(minTime),
 					end:            timestamp.FromTime(maxTime),

diff --git a/pkg/store/prometheus.go b/pkg/store/prometheus.go
@@ -704,11 +704,16 @@ func (p *PrometheusStore) LabelValues(ctx context.Context, r *storepb.LabelValue
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 	if !match {
-		return &storepb.LabelValuesResponse{Values: nil}, nil
+		return &storepb.LabelValuesResponse{}, nil
 	}
 
 	// First check for matching external label which has priority.
 	if l := extLset.Get(r.Label); l != "" {
+		for _, m := range matchers {
+			if !m.Matches(l) {
+				return &storepb.LabelValuesResponse{}, nil
+			}
+		}
 		return &storepb.LabelValuesResponse{Values: []string{l}}, nil
 	}
 

diff --git a/pkg/store/tsdb.go b/pkg/store/tsdb.go
@@ -341,10 +341,15 @@ func (s *TSDBStore) LabelValues(ctx context.Context, r *storepb.LabelValuesReque
 	}
 
 	if !match {
-		return &storepb.LabelValuesResponse{Values: nil}, nil
+		return &storepb.LabelValuesResponse{}, nil
 	}
 
 	if v := s.getExtLset().Get(r.Label); v != "" {
+		for _, m := range matchers {
+			if !m.Matches(v) {
+				return &storepb.LabelValuesResponse{}, nil
+			}
+		}
 		return &storepb.LabelValuesResponse{Values: []string{v}}, nil
 	}