From 64a383f22f5b2a2ad53e8b373f7cbc7468815efb Mon Sep 17 00:00:00 2001
From: Miciah Masters <miciah.masters@gmail.com>
Date: Thu, 26 May 2022 17:44:19 -0400
Subject: [PATCH] UPSTREAM: <carry>: openshift: Revert "Revert "add wildcard
 warnings (#5030)" (#5167)"

This reverts commit 4693f40990cd6fbd798962d6ac15d8aea9c8b737.
---
 plugin/kubernetes/handler.go    | 11 +++++++++++
 plugin/kubernetes/kubernetes.go |  1 +
 plugin/kubernetes/setup.go      | 21 +++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/plugin/kubernetes/handler.go b/plugin/kubernetes/handler.go
index d673a7a40f3b..ddf65b42ac8a 100644
--- a/plugin/kubernetes/handler.go
+++ b/plugin/kubernetes/handler.go
@@ -2,6 +2,8 @@ package kubernetes
 
 import (
 	"context"
+	"strings"
+	"sync/atomic"
 
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/request"
@@ -28,6 +30,10 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 		err       error
 	)
 
+	if wildQuestion(state.Name()) {
+		atomic.AddUint64(&wildCount, 1)
+	}
+
 	switch state.QType() {
 	case dns.TypeA:
 		records, truncated, err = plugin.A(ctx, &k, zone, state, nil, plugin.Options{})
@@ -87,8 +93,13 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 	m.Answer = append(m.Answer, records...)
 	m.Extra = append(m.Extra, extra...)
 	w.WriteMsg(m)
+
 	return dns.RcodeSuccess, nil
 }
 
+func wildQuestion(name string) bool {
+	return strings.HasPrefix(name, "*.") || strings.HasPrefix(name, "any.") || strings.Contains(name, ".*.") || strings.Contains(name, ".any.")
+}
+
 // Name implements the Handler interface.
 func (k Kubernetes) Name() string { return "kubernetes" }
diff --git a/plugin/kubernetes/kubernetes.go b/plugin/kubernetes/kubernetes.go
index 77b44e71e192..01f309d9db50 100644
--- a/plugin/kubernetes/kubernetes.go
+++ b/plugin/kubernetes/kubernetes.go
@@ -90,6 +90,7 @@ var (
 	errNoItems        = errors.New("no items found")
 	errNsNotExposed   = errors.New("namespace is not exposed")
 	errInvalidRequest = errors.New("invalid query name")
+	wildCount         uint64
 )
 
 // Services implements the ServiceBackend interface.
diff --git a/plugin/kubernetes/setup.go b/plugin/kubernetes/setup.go
index 0b988a9a0741..31dba5d41bed 100644
--- a/plugin/kubernetes/setup.go
+++ b/plugin/kubernetes/setup.go
@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"sync/atomic"
+	"time"
 
 	"github.com/coredns/caddy"
 	"github.com/coredns/coredns/core/dnsserver"
@@ -59,6 +61,25 @@ func setup(c *caddy.Controller) error {
 		return nil
 	})
 
+	wildWarner := time.NewTicker(10 * time.Second)
+	c.OnStartup(func() error {
+		go func() {
+			for {
+				select {
+				case <-wildWarner.C:
+					if wc := atomic.SwapUint64(&wildCount, 0); wc > 0 {
+						log.Warningf("%d deprecated wildcard queries received. Wildcard queries will no longer be supported in the next minor release.", wc)
+					}
+				}
+			}
+		}()
+		return nil
+	})
+	c.OnShutdown(func() error {
+		wildWarner.Stop()
+		return nil
+	})
+
 	return nil
 }