johngmyers review: use sprig, fix ipv4 check

go.mod

@@ -30,6 +30,7 @@ require (
 	github.com/ffledgling/pdns-go v0.0.0-20180219074714-524e7daccd99
 	github.com/go-gandi/go-gandi v0.7.0
 	github.com/go-logr/logr v1.4.2
+	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572
 	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.6.0
 	github.com/gophercloud/gophercloud v1.12.0

go.sum

@@ -433,6 +433,7 @@ github.com/go-sql-driver/mysql v1.4.1/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
 github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 h1:tfuBGBXKqDEevZMzYi5KSi8KkcZtzBcTgAUUtapy0OI=
+github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572/go.mod h1:9Pwr4B2jHnOSGXyyzV8ROjYa2ojvAY6HCGYYfMoC3Ls=
 github.com/go-task/slim-sprig/v3 v3.0.0 h1:sUs3vkvUymDpBKi3qH1YSqBQk9+9D/8M2mN1vB6EwHI=
 github.com/go-task/slim-sprig/v3 v3.0.0/go.mod h1:W848ghGpv3Qj3dhTPRyJypKRiqCdHZiAzKg9hl15HA8=
 github.com/gobs/pretty v0.0.0-20180724170744-09732c25a95b h1:/vQ+oYKu+JoyaMPDsv5FzwuL2wwWBgBbtj/YLCi4LuA=

source/source.go

@@ -29,6 +29,7 @@ import (
 	"time"
 	"unicode"
 
+	sprig "github.com/go-task/slim-sprig"
 	log "github.com/sirupsen/logrus"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
@@ -147,12 +148,11 @@ func parseTemplate(fqdnTemplate string) (tmpl *template.Template, err error) {
 	if fqdnTemplate == "" {
 		return nil, nil
 	}
-	funcs := template.FuncMap{
-		"trimPrefix": strings.TrimPrefix,
-		"replaceAll": strings.ReplaceAll,
-		"isIPv6":     isIPv6String,
-		"isIPv4":     isIPv4String,
-	}
+
+	funcs := sprig.HermeticTxtFuncMap()
+	funcs["isIPv6"] = isIPv6String
+	funcs["isIPv4"] = isIPv4String
+
 	return template.New("endpoint").Funcs(funcs).Parse(fqdnTemplate)
 }
 
@@ -399,5 +399,5 @@ func isIPv6String(ip string) bool {
 
 func isIPv4String(input string) bool {
 	netIP := net.ParseIP(input)
-	return netIP != nil && netIP.To4() != nil
+	return netIP != nil && netIP.To4() != nil && !strings.Contains(input, ":")
 }