From 6833f5150df173ece62674712a3a82eb2d34d1c0 Mon Sep 17 00:00:00 2001
From: Ivan Hamilton <ivan@section.io>
Date: Fri, 18 Oct 2019 09:53:48 +1100
Subject: [PATCH 1/3] Update moved package name

---
 setup.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/setup.go b/setup.go
index 9fb7b66..d5fd11d 100644
--- a/setup.go
+++ b/setup.go
@@ -4,7 +4,7 @@ import (
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/plugin"
 
-	"github.com/mholt/caddy"
+	"github.com/caddyserver/caddy"
 )
 
 func init() {

From 6d09a7448ceb55e5f4e9fb50520328985a2cd7b6 Mon Sep 17 00:00:00 2001
From: Ivan Hamilton <ivan@section.io>
Date: Fri, 18 Oct 2019 09:58:31 +1100
Subject: [PATCH 2/3] Add go.mod Mimic replace config from coredns (v1.6.4 -
 b139ba3)

---
 go.mod | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 go.mod

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..f06cfd0
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,16 @@
+module github.com/serverwentdown/alias
+
+go 1.13
+
+require (
+	github.com/caddyserver/caddy v1.0.3
+	github.com/coredns/coredns v1.6.4
+	github.com/miekg/dns v1.1.17
+	golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297
+)
+
+replace (
+	github.com/Azure/go-autorest => github.com/Azure/go-autorest v13.0.0+incompatible
+	github.com/miekg/dns v1.1.3 => github.com/miekg/dns v1.1.17
+	golang.org/x/net v0.0.0-20190813000000-74dc4d7220e7 => golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297
+)

From f4d7207770d52fd8588f30b9a59178f25c6033a5 Mon Sep 17 00:00:00 2001
From: Ivan Hamilton <ivan@section.io>
Date: Fri, 18 Oct 2019 15:45:39 +1100
Subject: [PATCH 3/3] Flatten CNAME records beyond first

---
 alias.go | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/alias.go b/alias.go
index 3b8db63..ed375ad 100644
--- a/alias.go
+++ b/alias.go
@@ -4,6 +4,7 @@ import (
 	"github.com/coredns/coredns/plugin"
 
 	"github.com/miekg/dns"
+	"math"
 
 	"golang.org/x/net/context"
 )
@@ -33,6 +34,13 @@ func NewResponseModifier(w dns.ResponseWriter) *ResponseModifier {
 	}
 }
 
+func min(a, b uint32) uint32 {
+	if a < b {
+		return a
+	}
+	return b
+}
+
 // WriteMsg records the status code and calls the
 // underlying ResponseWriter's WriteMsg method.
 func (r *ResponseModifier) WriteMsg(res *dns.Msg) error {
@@ -46,24 +54,26 @@ func (r *ResponseModifier) WriteMsg(res *dns.Msg) error {
 
 	// Find and delete CNAME record on that zone, storing the canonical name.
 	var (
-		cname string
-		ttl   uint32
+		cname string = zone
+		ttl   uint32 = math.MaxUint32
 	)
-	for i, rr := range res.Answer {
-		if rr.Header().Rrtype == dns.TypeCNAME && rr.Header().Name == zone {
+	for i := 0; i < len(res.Answer); {
+		rr := res.Answer[i]
+		if rr.Header().Rrtype == dns.TypeCNAME && rr.Header().Name == cname {
 			cname = rr.(*dns.CNAME).Target
-			ttl = rr.(*dns.CNAME).Header().Ttl
+			ttl = min(ttl, rr.(*dns.CNAME).Header().Ttl)
 			// Remove the CNAME record
 			res.Answer = append(res.Answer[:i], res.Answer[i+1:]...)
-			break
+			continue
 		}
+		i++
 	}
 
 	// Rename all the records with the above canonical name to the zone name
 	for _, rr := range res.Answer {
 		if rr.Header().Name == cname {
 			rr.Header().Name = zone
-			rr.Header().Ttl = ttl
+			rr.Header().Ttl = min(ttl, rr.Header().Ttl)
 		}
 	}