Add a DiffSupress for ipv6 shortening (#1551)

google/resource_dns_record_set.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/terraform/helper/schema"
 	"google.golang.org/api/dns/v1"
+	"net"
 )
 
 func resourceDnsRecordSet() *schema.Resource {
@@ -38,6 +39,12 @@ func resourceDnsRecordSet() *schema.Resource {
 				Required: true,
 				Elem: &schema.Schema{
 					Type: schema.TypeString,
+					DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+						if d.Get("type") == "AAAA" {
+							return ipv6AddressDiffSuppress(k, old, new, d)
+						}
+						return false
+					},
 				},
 				DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
 					return strings.ToLower(strings.Trim(old, `"`)) == strings.ToLower(strings.Trim(new, `"`))
@@ -320,3 +327,10 @@ func rrdata(
 	}
 	return data
 }
+
+func ipv6AddressDiffSuppress(_, old, new string, _ *schema.ResourceData) bool {
+	oldIp := net.ParseIP(old)
+	newIp := net.ParseIP(new)
+
+	return oldIp.Equal(newIp)
+}

google/resource_dns_record_set_test.go

@@ -9,6 +9,31 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
+func TestIpv6AddressDiffSuppress(t *testing.T) {
+	cases := map[string]struct {
+		Old, New       string
+		ShouldSuppress bool
+	}{
+		"compact form should suppress diff": {
+			Old:            "2a03:b0c0:1:e0::29b:8001",
+			New:            "2a03:b0c0:0001:00e0:0000:0000:029b:8001",
+			ShouldSuppress: true,
+		},
+		"different address should not suppress diff": {
+			Old:            "2a03:b0c0:1:e00::29b:8001",
+			New:            "2a03:b0c0:0001:00e0:0000:0000:029b:8001",
+			ShouldSuppress: false,
+		},
+	}
+
+	for tn, tc := range cases {
+		shouldSuppress := ipv6AddressDiffSuppress("", tc.Old, tc.New, nil)
+		if shouldSuppress != tc.ShouldSuppress {
+			t.Errorf("%s: expected %t", tn, tc.ShouldSuppress)
+		}
+	}
+}
+
 func TestAccDnsRecordSet_basic(t *testing.T) {
 	t.Parallel()