From 5cebb62184e992600690ad841853685dd27ae15e Mon Sep 17 00:00:00 2001
From: taku-k <taakuu19@gmail.com>
Date: Thu, 12 Oct 2017 16:41:30 +0900
Subject: [PATCH] Fix to return empty slice

---
 pkg/ipam/ip.go        | 8 +++++++-
 pkg/ipam/ipam.go      | 8 +++++---
 pkg/ipam/pool_test.go | 8 ++++++--
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/pkg/ipam/ip.go b/pkg/ipam/ip.go
index 2d2052a..111dc4f 100644
--- a/pkg/ipam/ip.go
+++ b/pkg/ipam/ip.go
@@ -47,6 +47,12 @@ func getIPAddr(r *storage.Redis, ip net.IP) (*model.IPAddr, error) {
 }
 
 func getIPAddrs(r *storage.Redis, ips []net.IP) ([]*model.IPAddr, error) {
+	addrs := make([]*model.IPAddr, len(ips))
+
+	if len(ips) == 0 {
+		return addrs, nil
+	}
+
 	dkeys := make([]string, len(ips))
 	for i, ip := range ips {
 		dkeys[i] = makeIPDetailsKey(ip)
@@ -55,7 +61,7 @@ func getIPAddrs(r *storage.Redis, ips []net.IP) ([]*model.IPAddr, error) {
 	if err != nil {
 		return nil, err
 	}
-	addrs := make([]*model.IPAddr, len(ips))
+
 	for i, d := range data {
 		if s, ok := d.(string); ok {
 			addrs[i] = &model.IPAddr{}
diff --git a/pkg/ipam/ipam.go b/pkg/ipam/ipam.go
index ab003e5..ceb0cd1 100644
--- a/pkg/ipam/ipam.go
+++ b/pkg/ipam/ipam.go
@@ -292,9 +292,11 @@ func (m *IPManager) CreatePool(ctx context.Context, n *model.Network, pool *mode
 		}
 		members = append(members, z)
 	}
-	_, err = m.redis.Client.ZAdd(usedkey, members...).Result()
-	if err != nil {
-		return err
+	if len(members) != 0 {
+		_, err = m.redis.Client.ZAdd(usedkey, members...).Result()
+		if err != nil {
+			return err
+		}
 	}
 
 	return setPool(m.redis, n, pool)
diff --git a/pkg/ipam/pool_test.go b/pkg/ipam/pool_test.go
index abd5727..ba3412a 100644
--- a/pkg/ipam/pool_test.go
+++ b/pkg/ipam/pool_test.go
@@ -28,8 +28,12 @@ func Test_getPools(t *testing.T) {
 		Status: model.Network_AVAILABLE,
 	}
 
-	_ = m.CreateNetwork(ctx, n)
-	_ = m.CreatePool(ctx, n, pool)
+	if err := m.CreateNetwork(ctx, n); err != nil {
+		t.Fatalf("CreateNetwork returns error %v; want success", err)
+	}
+	if err := m.CreatePool(ctx, n, pool); err != nil {
+		t.Fatalf("CreatePool returns error %v; want success", err)
+	}
 
 	pools, err := getPoolsInNetwork(r, n)
 	if err != nil {