add tests + nits

pkg/storage/bucket/named_stores.go

@@ -2,6 +2,7 @@ package bucket
 
 import (
 	"fmt"
+	"slices"
 
 	"github.com/grafana/loki/v3/pkg/storage/bucket/azure"
 	"github.com/grafana/loki/v3/pkg/storage/bucket/filesystem"
@@ -38,8 +39,7 @@ func (ns *NamedStores) populateStoreType() error {
 	ns.storeType = make(map[string]string)
 
 	checkForDuplicates := func(name string) error {
-		switch name {
-		case S3, GCS, Azure, Swift, Filesystem:
+		if slices.Contains(SupportedBackends, name) {
 			return fmt.Errorf("named store %q should not match with the name of a predefined storage type", name)
 		}
 
@@ -89,10 +89,6 @@ func (ns *NamedStores) populateStoreType() error {
 }
 
 func (ns *NamedStores) LookupStoreType(name string) (string, bool) {
-	if ns == nil {
-		return "", false
-	}
-
 	st, ok := ns.storeType[name]
 	return st, ok
 }

pkg/storage/bucket/named_stores_test.go

@@ -0,0 +1,92 @@
+package bucket
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/grafana/loki/v3/pkg/storage/bucket/gcs"
+)
+
+func TestNamedStores_populateStoreType(t *testing.T) {
+	t.Run("found duplicates", func(t *testing.T) {
+		ns := NamedStores{
+			S3: map[string]NamedS3StorageConfig{
+				"store-1": {},
+				"store-2": {},
+			},
+			GCS: map[string]NamedGCSStorageConfig{
+				"store-1": {},
+			},
+		}
+
+		err := ns.populateStoreType()
+		require.ErrorContains(t, err, `named store "store-1" is already defined under`)
+
+	})
+
+	t.Run("illegal store name", func(t *testing.T) {
+		ns := NamedStores{
+			GCS: map[string]NamedGCSStorageConfig{
+				"s3": {},
+			},
+		}
+
+		err := ns.populateStoreType()
+		require.ErrorContains(t, err, `named store "s3" should not match with the name of a predefined storage type`)
+
+	})
+
+	t.Run("lookup populated entries", func(t *testing.T) {
+		ns := NamedStores{
+			S3: map[string]NamedS3StorageConfig{
+				"store-1": {},
+				"store-2": {},
+			},
+			GCS: map[string]NamedGCSStorageConfig{
+				"store-3": {},
+			},
+		}
+
+		err := ns.populateStoreType()
+		require.NoError(t, err)
+
+		storeType, ok := ns.LookupStoreType("store-1")
+		require.True(t, ok)
+		require.Equal(t, S3, storeType)
+
+		storeType, ok = ns.LookupStoreType("store-2")
+		require.True(t, ok)
+		require.Equal(t, S3, storeType)
+
+		storeType, ok = ns.LookupStoreType("store-3")
+		require.True(t, ok)
+		require.Equal(t, GCS, storeType)
+
+		_, ok = ns.LookupStoreType("store-4")
+		require.False(t, ok)
+	})
+}
+
+func TestNamedStores_OverrideConfig(t *testing.T) {
+	namedStoreCfg := NamedStores{
+		GCS: map[string]NamedGCSStorageConfig{
+			"store-1": {
+				BucketName:      "bar",
+				ChunkBufferSize: 100,
+			},
+			"store-2": {
+				BucketName: "baz",
+			},
+		},
+	}
+
+	storeCfg := Config{
+		GCS: gcs.Config{
+			BucketName: "foo",
+		},
+	}
+	namedStoreCfg.OverrideConfig(&storeCfg, "store-1", GCS)
+	require.Equal(t, "bar", storeCfg.GCS.BucketName)
+	require.Equal(t, 100, storeCfg.GCS.ChunkBufferSize)
+}

pkg/storage/bucket/object_client_adapter.go

@@ -38,26 +38,26 @@ func NewObjectClient(ctx context.Context, backend string, cfg ConfigWithNamedSto
 		}
 	}
 
-	b, err := NewClient(ctx, storeType, storeCfg, component, logger, nil)
+	bucket, err := NewClient(ctx, storeType, storeCfg, component, logger, nil)
 	if err != nil {
 		return nil, fmt.Errorf("create bucket: %w", err)
 	}
 
-	hedgedBucket := b
+	hedgedBucket := bucket
 	if hedgingCfg.At != 0 {
 		hedgedTrasport, err := hedgingCfg.RoundTripperWithRegisterer(nil, prometheus.WrapRegistererWithPrefix("loki_", prometheus.DefaultRegisterer))
 		if err != nil {
 			return nil, fmt.Errorf("create hedged transport: %w", err)
 		}
 
-		b, err = NewClient(ctx, storeType, storeCfg, component, logger, hedgedTrasport)
+		bucket, err = NewClient(ctx, storeType, storeCfg, component, logger, hedgedTrasport)
 		if err != nil {
 			return nil, fmt.Errorf("create hedged bucket: %w", err)
 		}
 	}
 
 	o := &ObjectClientAdapter{
-		bucket:       b,
+		bucket:       bucket,
 		hedgedBucket: hedgedBucket,
 		logger:       log.With(logger, "component", "bucket_to_object_client_adapter"),
 		// default to no retryable errors. Override with WithRetryableErrFunc