Update to work with Terraform 0.12

main.go

@@ -31,7 +31,7 @@ const (
 	recordTemplateStr = `{{- range .Record.Comments }}
 # {{ . }}{{ end }}
 resource "aws_route53_record" "{{ .ResourceID }}" {
-  zone_id = "${aws_route53_zone.{{ .ZoneID }}.zone_id}"
+  zone_id = {{ zoneReference .ZoneID }}
   name    = "{{ .Record.Name }}"
   type    = "{{ .Record.Type }}"
   ttl     = "{{ .Record.TTL }}"
@@ -40,11 +40,41 @@ resource "aws_route53_record" "{{ .ResourceID }}" {
 `
 )
 
-var (
-	zoneTemplate   = template.Must(template.New("zone").Parse(zoneTemplateStr))
-	recordTemplate = template.Must(template.New("record").Funcs(template.FuncMap{"ensureQuoted": ensureQuoted}).Parse(recordTemplateStr))
+type syntaxMode uint8
+
+func (m syntaxMode) String() string {
+	switch m {
+	case Modern:
+		return "modern"
+	case Legacy:
+		return "legacy"
+	default:
+		panic("Unknown syntax")
+	}
+}
+
+const (
+	Modern syntaxMode = iota
+	Legacy
 )
 
+type configGenerator struct {
+	zoneTemplate   *template.Template
+	recordTemplate *template.Template
+
+	syntax syntaxMode
+}
+
+func newConfigGenerator(syntax syntaxMode) *configGenerator {
+	g := &configGenerator{syntax: syntax}
+	g.zoneTemplate = template.Must(template.New("zone").Parse(zoneTemplateStr))
+	g.recordTemplate = template.Must(template.New("record").Funcs(template.FuncMap{
+		"ensureQuoted":  ensureQuoted,
+		"zoneReference": g.zoneReference,
+	}).Parse(recordTemplateStr))
+	return g
+}
+
 type zoneTemplateData struct {
 	ID     string
 	Domain string
@@ -87,6 +117,7 @@ var (
 	domain           = flag.String("domain", "", "Name of domain")
 	zoneFile         = flag.String("zone-file", "", "Path to zone file. Defaults to <domain>.zone in working dir")
 	showVersion      = flag.Bool("version", false, "Show version")
+	legacySyntax     = flag.Bool("legacy-syntax", false, "Generate legacy terraform syntax (versions older than 0.12)")
 )
 
 func main() {
@@ -110,13 +141,20 @@ func main() {
 		log.Fatal(err)
 	}
 
-	generateTerraformForZone(*domain, excludedTypes, fileReader, os.Stdout)
+	var syntax syntaxMode
+	if !*legacySyntax {
+		syntax = Modern
+	} else {
+		syntax = Legacy
+	}
+	g := newConfigGenerator(syntax)
+	g.generateTerraformForZone(*domain, excludedTypes, fileReader, os.Stdout)
 }
 
-func generateTerraformForZone(domain string, excludedTypes map[uint16]bool, zoneReader io.Reader, output io.Writer) {
+func (g *configGenerator) generateTerraformForZone(domain string, excludedTypes map[uint16]bool, zoneReader io.Reader, output io.Writer) {
 	records := readZoneRecords(zoneReader, excludedTypes)
 
-	zoneID, err := generateZoneResource(domain, output)
+	zoneID, err := g.generateZoneResource(domain, output)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -129,7 +167,7 @@ func generateTerraformForZone(domain string, excludedTypes map[uint16]bool, zone
 
 	for _, key := range recordKeys {
 		rec := records[key]
-		err := generateRecordResource(rec, zoneID, output)
+		err := g.generateRecordResource(rec, zoneID, output)
 		if err != nil {
 			log.Printf("Error: %v\n", err)
 			continue
@@ -163,18 +201,18 @@ func readZoneRecords(zoneReader io.Reader, excludedTypes map[uint16]bool) map[re
 	return records
 }
 
-func generateZoneResource(domain string, w io.Writer) (string, error) {
+func (g *configGenerator) generateZoneResource(domain string, w io.Writer) (string, error) {
 	zoneName := strings.TrimRight(domain, ".")
 	data := zoneTemplateData{
 		ID:     strings.Replace(zoneName, ".", "-", -1),
 		Domain: zoneName,
 	}
 
-	err := zoneTemplate.Execute(w, data)
+	err := g.zoneTemplate.Execute(w, data)
 	return data.ID, err
 }
 
-func generateRecordResource(record dnsRecord, zoneID string, w io.Writer) error {
+func (g *configGenerator) generateRecordResource(record dnsRecord, zoneID string, w io.Writer) error {
 	sanitizedName := sanitizeRecordName(record.Name)
 	id := fmt.Sprintf("%s-%s", sanitizedName, record.Type)
 
@@ -184,7 +222,7 @@ func generateRecordResource(record dnsRecord, zoneID string, w io.Writer) error
 		ZoneID:     zoneID,
 	}
 
-	return recordTemplate.Execute(w, data)
+	return g.recordTemplate.Execute(w, data)
 }
 
 func mergeRecords(a, b dnsRecord) dnsRecord {
@@ -267,3 +305,14 @@ func ensureQuoted(s string) string {
 	}
 	return fmt.Sprintf("%q", s)
 }
+
+func (g *configGenerator) zoneReference(zone string) string {
+	switch g.syntax {
+	case Modern:
+		return fmt.Sprintf("aws_route53_zone.%s.zone_id", zone)
+	case Legacy:
+		return fmt.Sprintf(`"${aws_route53_zone.%s.zone_id}"`, zone)
+	default:
+		panic(fmt.Sprintf("Unknown mode %v", g.syntax))
+	}
+}

main_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -11,10 +12,16 @@ import (
 	"github.com/google/go-cmp/cmp"
 )
 
-var diffOpts = cmp.Options{
-	cmp.Transformer("ignoreSurroundingWhitespace", func(in string) string {
-		return strings.TrimSpace(in)
-	}),
+var (
+	diffOpts = cmp.Options{
+		cmp.Transformer("ignoreSurroundingWhitespace", func(in string) string {
+			return strings.TrimSpace(in)
+		}),
+	}
+)
+
+func caseName(name string, syntax syntaxMode) string {
+	return fmt.Sprintf("%s-%v", name, syntax)
 }
 
 func TestGenerateRecordResource(t *testing.T) {
@@ -25,23 +32,49 @@ func TestGenerateRecordResource(t *testing.T) {
 		TTL:      3600,
 		Comments: []string{"This is a test"},
 	}
-	expected := `# This is a test
+
+	cases := []struct {
+		name     string
+		expected map[syntaxMode]string
+	}{
+		{
+			name: "basic",
+			expected: map[syntaxMode]string{
+				Modern: `# This is a test
+resource "aws_route53_record" "foo-bar-A" {
+  zone_id = aws_route53_zone.test-zone.zone_id
+  name    = "foo.bar"
+  type    = "A"
+  ttl     = "3600"
+  records = ["127.0.0.1"]
+}`,
+				Legacy: `# This is a test
 resource "aws_route53_record" "foo-bar-A" {
   zone_id = "${aws_route53_zone.test-zone.zone_id}"
   name    = "foo.bar"
   type    = "A"
   ttl     = "3600"
   records = ["127.0.0.1"]
-}`
-
-	var buf bytes.Buffer
-	err := generateRecordResource(record, "test-zone", &buf)
-	if err != nil {
-		t.Fatal(err)
+}`,
+			},
+		},
 	}
+	for _, tc := range cases {
+		for _, legacySyntax := range []syntaxMode{Modern, Legacy} {
+			t.Run(caseName(tc.name, legacySyntax), func(t *testing.T) {
+				g := newConfigGenerator(legacySyntax)
+
+				var buf bytes.Buffer
+				err := g.generateRecordResource(record, "test-zone", &buf)
+				if err != nil {
+					t.Fatal(err)
+				}
 
-	if diff := cmp.Diff(expected, buf.String(), diffOpts); diff != "" {
-		t.Errorf("Unexpected result from resource generation (-want +got):\n%s", diff)
+				if diff := cmp.Diff(tc.expected[legacySyntax], buf.String(), diffOpts); diff != "" {
+					t.Errorf("Unexpected result from resource generation (-want +got):\n%s", diff)
+				}
+			})
+		}
 	}
 }
 
@@ -74,24 +107,27 @@ func TestAcceptance(t *testing.T) {
 	}
 
 	for _, n := range fileNames {
-		t.Run(n, func(t *testing.T) {
-			file, err := os.Open(n)
-			if err != nil {
-				panic(err)
-			}
-			expected, err := ioutil.ReadFile(strings.Replace(n, ".zone", ".expected", 1))
-			if err != nil {
-				panic(err)
-			}
+		for _, syntax := range []syntaxMode{Modern, Legacy} {
+			t.Run(caseName(n, syntax), func(t *testing.T) {
+				file, err := os.Open(n)
+				if err != nil {
+					panic(err)
+				}
+				expected, err := ioutil.ReadFile(strings.Replace(n, ".zone", fmt.Sprintf(".expected-%v", syntax), 1))
+				if err != nil {
+					panic(err)
+				}
 
-			var buf bytes.Buffer
-			domain := strings.Replace(filepath.Base(n), ".zone", "", 1)
-			excludedTypes := excludedTypesFromString("SOA,NS")
-			generateTerraformForZone(domain, excludedTypes, file, &buf)
+				g := newConfigGenerator(syntax)
+				var buf bytes.Buffer
+				domain := strings.Replace(filepath.Base(n), ".zone", "", 1)
+				excludedTypes := excludedTypesFromString("SOA,NS")
+				g.generateTerraformForZone(domain, excludedTypes, file, &buf)
 
-			if diff := cmp.Diff(string(expected), buf.String(), diffOpts); diff != "" {
-				t.Errorf("Unexpected result from full Terraform output (-want +got):\n%s", diff)
-			}
-		})
+				if diff := cmp.Diff(string(expected), buf.String(), diffOpts); diff != "" {
+					t.Errorf("Unexpected result from full Terraform output (-want +got):\n%s", diff)
+				}
+			})
+		}
 	}
 }

testdata/example.com.expected-modern

@@ -0,0 +1,96 @@
+resource "aws_route53_zone" "example-com" {
+  name = "example.com"
+}
+
+#  wwwtest.example.com is another alias for www.example.com
+resource "aws_route53_record" "wwwtest-example-com-CNAME" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "wwwtest.example.com."
+  type    = "CNAME"
+  ttl     = "3600"
+  records = ["www.example.com."]
+}
+
+#  www.example.com is an alias for example.com
+resource "aws_route53_record" "www-example-com-CNAME" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "www.example.com."
+  type    = "CNAME"
+  ttl     = "3600"
+  records = ["example.com."]
+}
+
+#  IPv6 address for ns.example.com
+resource "aws_route53_record" "ns-example-com-AAAA" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "ns.example.com."
+  type    = "AAAA"
+  ttl     = "3600"
+  records = ["2001:db8:10::2"]
+}
+
+#  IPv4 address for ns.example.com
+resource "aws_route53_record" "ns-example-com-A" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "ns.example.com."
+  type    = "A"
+  ttl     = "3600"
+  records = ["192.0.2.2"]
+}
+
+#  IPv4 address for mail3.example.com
+resource "aws_route53_record" "mail3-example-com-A" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "mail3.example.com."
+  type    = "A"
+  ttl     = "3600"
+  records = ["192.0.2.5"]
+}
+
+#  IPv4 address for mail2.example.com
+resource "aws_route53_record" "mail2-example-com-A" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "mail2.example.com."
+  type    = "A"
+  ttl     = "3600"
+  records = ["192.0.2.4"]
+}
+
+#  IPv4 address for mail.example.com
+resource "aws_route53_record" "mail-example-com-A" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "mail.example.com."
+  type    = "A"
+  ttl     = "3600"
+  records = ["192.0.2.3"]
+}
+
+#  mail.example.com is the mailserver for example.com
+#  equivalent to above line, "@" represents zone origin
+#  equivalent to above line, but using a relative host name
+resource "aws_route53_record" "example-com-MX" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "example.com."
+  type    = "MX"
+  ttl     = "3600"
+  records = ["10 mail.example.com.", "20 mail2.example.com.", "50 mail3.example.com."]
+}
+
+#  IPv6 address for example.com
+resource "aws_route53_record" "example-com-AAAA" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "example.com."
+  type    = "AAAA"
+  ttl     = "3600"
+  records = ["2001:db8:10::1"]
+}
+
+#  IPv4 address for example.com
+resource "aws_route53_record" "example-com-A" {
+  zone_id = aws_route53_zone.example-com.zone_id
+  name    = "example.com."
+  type    = "A"
+  ttl     = "3600"
+  records = ["192.0.2.1"]
+}
+