From 36d5eb0a479ea0cf090be92c248a62fa31fe772a Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Wed, 19 Sep 2018 11:42:19 -0700
Subject: [PATCH 1/2] pkg/ipnet: Teach IPNet.String() to handle nil receivers

Instead of panicking.  This makes some comparisons easier, as you can
see from the test changes.
---
 pkg/ipnet/ipnet.go      |  9 +++++++++
 pkg/ipnet/ipnet_test.go | 18 +++++++-----------
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/pkg/ipnet/ipnet.go b/pkg/ipnet/ipnet.go
index 48ca01e6706..e6a4c3e4f5e 100644
--- a/pkg/ipnet/ipnet.go
+++ b/pkg/ipnet/ipnet.go
@@ -16,6 +16,15 @@ type IPNet struct {
 	net.IPNet
 }
 
+// String returns a CIDR serialization of the subnet, or an empty
+// string if the subnet is nil.
+func (ipnet *IPNet) String() string {
+	if ipnet == nil {
+		return ""
+	}
+	return ipnet.IPNet.String()
+}
+
 // MarshalJSON interface for an IPNet
 func (ipnet IPNet) MarshalJSON() (data []byte, err error) {
 	if reflect.DeepEqual(ipnet.IPNet, emptyIPNet) {
diff --git a/pkg/ipnet/ipnet_test.go b/pkg/ipnet/ipnet_test.go
index 94b927d6f47..a072a4a907e 100644
--- a/pkg/ipnet/ipnet_test.go
+++ b/pkg/ipnet/ipnet_test.go
@@ -38,23 +38,19 @@ func TestUnmarshal(t *testing.T) {
 			Mask: net.IPv4Mask(255, 255, 255, 0),
 		}},
 	} {
-		data, err := json.Marshal(ipNetIn)
-		if err != nil {
-			t.Fatal(err)
-		}
+		t.Run(ipNetIn.String(), func(t *testing.T) {
+			data, err := json.Marshal(ipNetIn)
+			if err != nil {
+				t.Fatal(err)
+			}
 
-		t.Run(string(data), func(t *testing.T) {
 			var ipNetOut *IPNet
-			err := json.Unmarshal(data, &ipNetOut)
+			err = json.Unmarshal(data, &ipNetOut)
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			if ipNetIn == nil {
-				if ipNetOut != nil {
-					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
-				}
-			} else if ipNetOut.String() != ipNetIn.String() {
+			if ipNetOut.String() != ipNetIn.String() {
 				t.Fatalf("%v != %v", ipNetOut, ipNetIn)
 			}
 		})

From 06739c665e9d3bc9b813ad873bed862a5bde24f1 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Tue, 18 Sep 2018 13:42:00 -0700
Subject: [PATCH 2/2] pkg/ipnet: Add DeepCopy and DeepCopyInto for IPNet

Devan needs DeepCopyInto on IPNet as part of embed our types into
Hive's ClusterDeployment CRD [1].  You could generate these with
deepcopy-gen [2], but setting up automatic code generation is a bit
heavy for just these methods [3], so we're hand-coding for now.

[1]: https://github.com/openshift/installer/issues/256#issue-360875062
[2]: https://godoc.org/k8s.io/gengo/examples/deepcopy-gen
[3]: https://github.com/openshift/installer/pull/276#issuecomment-422871376
---
 pkg/ipnet/ipnet.go      | 20 ++++++++++++++++++++
 pkg/ipnet/ipnet_test.go | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/pkg/ipnet/ipnet.go b/pkg/ipnet/ipnet.go
index e6a4c3e4f5e..fc66cd9360b 100644
--- a/pkg/ipnet/ipnet.go
+++ b/pkg/ipnet/ipnet.go
@@ -25,6 +25,26 @@ func (ipnet *IPNet) String() string {
 	return ipnet.IPNet.String()
 }
 
+// DeepCopyInto copies the receiver into out.  out must be non-nil.
+func (ipnet *IPNet) DeepCopyInto(out *IPNet) {
+	if ipnet == nil {
+		*out = *new(IPNet)
+	} else {
+		*out = *ipnet
+	}
+	return
+}
+
+// DeepCopy copies the receiver, creating a new IPNet.
+func (ipnet *IPNet) DeepCopy() *IPNet {
+	if ipnet == nil {
+		return nil
+	}
+	out := new(IPNet)
+	ipnet.DeepCopyInto(out)
+	return out
+}
+
 // MarshalJSON interface for an IPNet
 func (ipnet IPNet) MarshalJSON() (data []byte, err error) {
 	if reflect.DeepEqual(ipnet.IPNet, emptyIPNet) {
diff --git a/pkg/ipnet/ipnet_test.go b/pkg/ipnet/ipnet_test.go
index a072a4a907e..e12f3abaaef 100644
--- a/pkg/ipnet/ipnet_test.go
+++ b/pkg/ipnet/ipnet_test.go
@@ -56,3 +56,42 @@ func TestUnmarshal(t *testing.T) {
 		})
 	}
 }
+
+func TestDeepCopy(t *testing.T) {
+	for _, ipNetIn := range []*IPNet{
+		{},
+		{IPNet: net.IPNet{
+			IP:   net.IP{192, 168, 0, 10},
+			Mask: net.IPv4Mask(255, 255, 255, 0),
+		}},
+	} {
+		t.Run(ipNetIn.String(), func(t *testing.T) {
+			t.Run("DeepCopyInto", func(t *testing.T) {
+				ipNetOut := &IPNet{IPNet: net.IPNet{
+					IP:   net.IP{10, 0, 0, 0},
+					Mask: net.IPv4Mask(255, 0, 0, 0),
+				}}
+
+				ipNetIn.DeepCopyInto(ipNetOut)
+				if ipNetOut.String() != ipNetIn.String() {
+					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
+				}
+			})
+
+			t.Run("DeepCopy", func(t *testing.T) {
+				ipNetOut := ipNetIn.DeepCopy()
+				if ipNetOut.String() != ipNetIn.String() {
+					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
+				}
+
+				ipNetIn.IPNet = net.IPNet{
+					IP:   net.IP{192, 168, 10, 10},
+					Mask: net.IPv4Mask(255, 255, 255, 255),
+				}
+				if ipNetOut.String() == ipNetIn.String() {
+					t.Fatalf("%v (%q) == %v (%q)", ipNetOut, ipNetOut.String(), ipNetIn, ipNetIn.String())
+				}
+			})
+		})
+	}
+}