From 6b18338ccd5a88a066622b051e315a51600aec05 Mon Sep 17 00:00:00 2001
From: Michael Hoffmann <mhoffm@posteo.de>
Date: Mon, 22 Jan 2024 11:37:48 +0100
Subject: [PATCH] Store: acceptance test for proxy store (#7084)

* Add basic acceptance tests for proxy store
* Fix bug where invalid requests got ignored because of partial response
  strategy

Signed-off-by: Michael Hoffmann <mhoffm@posteo.de>
---
 pkg/store/acceptance_test.go | 28 ++++++++++++++++++++++++++++
 pkg/store/proxy.go           |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/pkg/store/acceptance_test.go b/pkg/store/acceptance_test.go
index 34abc649ab..069d732555 100644
--- a/pkg/store/acceptance_test.go
+++ b/pkg/store/acceptance_test.go
@@ -33,6 +33,7 @@ import (
 	"github.com/thanos-io/thanos/pkg/store/labelpb"
 	"github.com/thanos-io/thanos/pkg/store/storepb"
 	"github.com/thanos-io/thanos/pkg/store/storepb/prompb"
+	storetestutil "github.com/thanos-io/thanos/pkg/store/storepb/testutil"
 	"github.com/thanos-io/thanos/pkg/testutil/custom"
 	"github.com/thanos-io/thanos/pkg/testutil/e2eutil"
 )
@@ -965,3 +966,30 @@ func TestTSDBStore_Acceptance(t *testing.T) {
 	testStoreAPIsAcceptance(t, startStore)
 	testStoreAPIsSeriesSplitSamplesIntoChunksWithMaxSizeOf120(t, startStore)
 }
+
+func TestProxyStore_Acceptance(t *testing.T) {
+	t.Cleanup(func() { custom.TolerantVerifyLeak(t) })
+
+	startStore := func(tt *testing.T, extLset labels.Labels, appendFn func(app storage.Appender)) storepb.StoreServer {
+		startNestedStore := func(tt *testing.T, extLset labels.Labels, appendFn func(app storage.Appender)) storepb.StoreServer {
+			db, err := e2eutil.NewTSDB()
+			testutil.Ok(tt, err)
+			tt.Cleanup(func() { testutil.Ok(tt, db.Close()) })
+			appendFn(db.Appender(context.Background()))
+
+			return NewTSDBStore(nil, db, component.Rule, extLset)
+		}
+
+		p1 := startNestedStore(tt, extLset, appendFn)
+		p2 := startNestedStore(tt, extLset, appendFn)
+
+		clients := []Client{
+			storetestutil.TestClient{StoreClient: storepb.ServerAsClient(p1, 0)},
+			storetestutil.TestClient{StoreClient: storepb.ServerAsClient(p2, 0)},
+		}
+
+		return NewProxyStore(nil, nil, func() []Client { return clients }, component.Query, nil, 0*time.Second, RetrievalStrategy(EagerRetrieval))
+	}
+
+	testStoreAPIsAcceptance(t, startStore)
+}
diff --git a/pkg/store/proxy.go b/pkg/store/proxy.go
index ce4d391bf3..96a67f9b75 100644
--- a/pkg/store/proxy.go
+++ b/pkg/store/proxy.go
@@ -540,6 +540,9 @@ func (s *ProxyStore) LabelValues(ctx context.Context, r *storepb.LabelValuesRequ
 		g, gctx        = errgroup.WithContext(ctx)
 		storeDebugMsgs []string
 	)
+	if r.Label == "" {
+		return nil, status.Error(codes.InvalidArgument, "label name parameter cannot be empty")
+	}
 
 	// We may arrive here either via the promql engine
 	// or as a result of a grpc call in layered queries