Merge pull request #52753 from munnerz/sample-controller

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

sample-controller: add example CRD controller

**What this PR does / why we need it**:

Adds a sample-controller example repository

fixes #52752

**Special notes for your reviewer**:

This is currently based on the sttts:sttts-codegen-scripts branch and should not be merged until that is (ref https://github.com/kubernetes/kubernetes/pull/52186)

**Release note**:

```
Add sample-controller repository
```

/cc @sttts @nikhita @colemickens

Kubernetes-commit: 9a7800f7d2efb88b397674672ac56f898826cf7c

vendor/k8s.io/apimachinery/pkg/util/net/util.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"net"
+	"reflect"
+	"syscall"
+)
+
+// IPNetEqual checks if the two input IPNets are representing the same subnet.
+// For example,
+//	10.0.0.1/24 and 10.0.0.0/24 are the same subnet.
+//	10.0.0.1/24 and 10.0.0.0/25 are not the same subnet.
+func IPNetEqual(ipnet1, ipnet2 *net.IPNet) bool {
+	if ipnet1 == nil || ipnet2 == nil {
+		return false
+	}
+	if reflect.DeepEqual(ipnet1.Mask, ipnet2.Mask) && ipnet1.Contains(ipnet2.IP) && ipnet2.Contains(ipnet1.IP) {
+		return true
+	}
+	return false
+}
+
+// Returns if the given err is "connection reset by peer" error.
+func IsConnectionReset(err error) bool {
+	opErr, ok := err.(*net.OpError)
+	if ok && opErr.Err.Error() == syscall.ECONNRESET.Error() {
+		return true
+	}
+	return false
+}