From 824fc4ee20b1ebe076f6e25bd8e6ecc89d584498 Mon Sep 17 00:00:00 2001
From: Preetha Appan <preetha@hashicorp.com>
Date: Thu, 3 Aug 2017 14:47:07 -0500
Subject: [PATCH] Unify regex used to identify invalid dns characters

---
 agent/agent.go | 8 ++------
 agent/dns.go   | 4 ++--
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/agent/agent.go b/agent/agent.go
index ebb3228f58..99700f405c 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -13,7 +13,6 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -51,9 +50,6 @@ const (
 		"service, but no reason was provided. This is a default message."
 )
 
-// dnsNameRe checks if a name or tag is dns-compatible.
-var dnsNameRe = regexp.MustCompile(`^[a-zA-Z0-9\-]+$`)
-
 // delegate defines the interface shared by both
 // consul.Client and consul.Server.
 type delegate interface {
@@ -1370,7 +1366,7 @@ func (a *Agent) AddService(service *structs.NodeService, chkTypes []*structs.Che
 	}
 
 	// Warn if the service name is incompatible with DNS
-	if !dnsNameRe.MatchString(service.Service) {
+	if InvalidDnsRe.MatchString(service.Service) {
 		a.logger.Printf("[WARN] Service name %q will not be discoverable "+
 			"via DNS due to invalid characters. Valid characters include "+
 			"all alpha-numerics and dashes.", service.Service)
@@ -1378,7 +1374,7 @@ func (a *Agent) AddService(service *structs.NodeService, chkTypes []*structs.Che
 
 	// Warn if any tags are incompatible with DNS
 	for _, tag := range service.Tags {
-		if !dnsNameRe.MatchString(tag) {
+		if InvalidDnsRe.MatchString(tag) {
 			a.logger.Printf("[DEBUG] Service tag %q will not be discoverable "+
 				"via DNS due to invalid characters. Valid characters include "+
 				"all alpha-numerics and dashes.", tag)
diff --git a/agent/dns.go b/agent/dns.go
index 0678361706..8e458f6668 100644
--- a/agent/dns.go
+++ b/agent/dns.go
@@ -32,7 +32,7 @@ const (
 	defaultMaxUDPSize = 512
 )
 
-var invalidCharsRe = regexp.MustCompile(`[^A-Za-z0-9\\-]+`)
+var InvalidDnsRe = regexp.MustCompile(`[^A-Za-z0-9\\-]+`)
 
 // DNSServer is used to wrap an Agent and expose various
 // service discovery endpoints using a DNS interface.
@@ -691,7 +691,7 @@ func (d *DNSServer) addAuthority(msg *dns.Msg) {
 	serverAddrs := d.agent.delegate.ServerAddrs()
 	for name, addr := range serverAddrs {
 		ipAddrStr := strings.Split(addr, ":")[0]
-		sanitizedName := invalidCharsRe.ReplaceAllString(name, "-") // does some basic sanitization of the name
+		sanitizedName := InvalidDnsRe.ReplaceAllString(name, "-") // does some basic sanitization of the name
 		nsName := "server-" + sanitizedName + "." + d.domain
 		ip := net.ParseIP(ipAddrStr)
 		if ip != nil {