From 0ee56274e5b7fb4b96d78ebbe041bf967bc83e63 Mon Sep 17 00:00:00 2001
From: Injun Song <ijsong@gmail.com>
Date: Mon, 29 Aug 2022 17:49:15 +0900
Subject: [PATCH] fix: set empty list to `logStreams` when it is null

Resolves #88
---
 bin/start_varlogsn.py                         |  4 ++-
 internal/admin/stats/repository.go            |  9 +------
 internal/varlogctl/storagenode/storagenode.go | 25 +++++++++++++++++--
 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/bin/start_varlogsn.py b/bin/start_varlogsn.py
index b7770378b..14fba1fcc 100755
--- a/bin/start_varlogsn.py
+++ b/bin/start_varlogsn.py
@@ -61,7 +61,9 @@ def get_data_dirs(admin: str, snid: int):
            f"--snid={snid}"]
     out = subprocess.check_output(cmd)
     snm = json.loads(out)
-    logstreams = snm.get("logStreams", [])
+    logstreams = snm.get("logStreams")
+    if not logstreams:
+        logstreams = []
     return [logstream["path"] for logstream in logstreams]
 
 
diff --git a/internal/admin/stats/repository.go b/internal/admin/stats/repository.go
index fb0c24db7..a72f123c1 100644
--- a/internal/admin/stats/repository.go
+++ b/internal/admin/stats/repository.go
@@ -127,11 +127,7 @@ func (s *repository) GetStorageNode(snid types.StorageNodeID) (*vmspb.StorageNod
 	if !ok {
 		return nil, false
 	}
-	copied := proto.Clone(snm).(*vmspb.StorageNodeMetadata)
-	if len(copied.LogStreamReplicas) == 0 {
-		copied.LogStreamReplicas = []snpb.LogStreamReplicaMetadataDescriptor{}
-	}
-	return copied, true
+	return proto.Clone(snm).(*vmspb.StorageNodeMetadata), true
 }
 
 func (s *repository) ListStorageNodes() []vmspb.StorageNodeMetadata {
@@ -140,9 +136,6 @@ func (s *repository) ListStorageNodes() []vmspb.StorageNodeMetadata {
 	snms := make([]vmspb.StorageNodeMetadata, 0, len(s.storageNodes))
 	for _, snm := range s.storageNodes {
 		copied := *proto.Clone(snm).(*vmspb.StorageNodeMetadata)
-		if len(copied.LogStreamReplicas) == 0 {
-			copied.LogStreamReplicas = []snpb.LogStreamReplicaMetadataDescriptor{}
-		}
 		snms = append(snms, copied)
 	}
 	sort.Slice(snms, func(i, j int) bool {
diff --git a/internal/varlogctl/storagenode/storagenode.go b/internal/varlogctl/storagenode/storagenode.go
index 3b4b5fe9f..026c4a9c3 100644
--- a/internal/varlogctl/storagenode/storagenode.go
+++ b/internal/varlogctl/storagenode/storagenode.go
@@ -8,14 +8,35 @@ import (
 	"github.com/kakao/varlog/internal/varlogctl"
 	"github.com/kakao/varlog/pkg/types"
 	"github.com/kakao/varlog/pkg/varlog"
+	"github.com/kakao/varlog/proto/snpb"
+	"github.com/kakao/varlog/proto/vmspb"
 )
 
 func Describe(snid ...types.StorageNodeID) varlogctl.ExecuteFunc {
 	return func(ctx context.Context, adm varlog.Admin) (any, error) {
 		if len(snid) > 0 {
-			return adm.GetStorageNode(ctx, snid[0])
+			snm, err := adm.GetStorageNode(ctx, snid[0])
+			if err != nil {
+				return nil, err
+			}
+			ensureEmptyFields(snm)
+			return snm, nil
+
+		}
+		snms, err := adm.ListStorageNodes(ctx)
+		if err != nil {
+			return nil, err
+		}
+		for idx := range snms {
+			ensureEmptyFields(&snms[idx])
 		}
-		return adm.ListStorageNodes(ctx)
+		return snms, nil
+	}
+}
+
+func ensureEmptyFields(snm *vmspb.StorageNodeMetadata) {
+	if len(snm.LogStreamReplicas) == 0 {
+		snm.LogStreamReplicas = []snpb.LogStreamReplicaMetadataDescriptor{}
 	}
 }