From 65bca041906e45ef3c3da21efae81a9ecc926b0b Mon Sep 17 00:00:00 2001
From: Ujjwal Kumar <Ujjwal.Kumar1@ibm.com>
Date: Fri, 22 Sep 2023 15:56:05 +0530
Subject: [PATCH] list to set

---
 ibm/service/vpc/resource_ibm_is_vpc.go      | 17 ++++++++++++++---
 ibm/service/vpc/resource_ibm_is_vpc_test.go |  2 --
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/ibm/service/vpc/resource_ibm_is_vpc.go b/ibm/service/vpc/resource_ibm_is_vpc.go
index 416284b616..c3df4dcceb 100644
--- a/ibm/service/vpc/resource_ibm_is_vpc.go
+++ b/ibm/service/vpc/resource_ibm_is_vpc.go
@@ -4,6 +4,7 @@
 package vpc
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"log"
@@ -18,6 +19,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 
+	"github.com/IBM-Cloud/terraform-provider-ibm/ibm/conns"
 	"github.com/IBM-Cloud/terraform-provider-ibm/ibm/flex"
 	"github.com/IBM-Cloud/terraform-provider-ibm/ibm/validate"
 )
@@ -220,9 +222,10 @@ func ResourceIBMISVPC() *schema.Resource {
 									},
 
 									isVPCDnsResolverManualServers: &schema.Schema{
-										Type:        schema.TypeList,
+										Type:        schema.TypeSet,
 										Optional:    true,
 										Computed:    true,
+										Set:         hashManualServersList,
 										Description: "The manually specified DNS servers for this VPC.",
 										Elem: &schema.Resource{
 											Schema: map[string]*schema.Schema{
@@ -1221,7 +1224,7 @@ func vpcUpdate(d *schema.ResourceData, meta interface{}, id, name string, hasCha
 
 					if newResolverManualServers != nil {
 						manualServers := []vpcv1.DnsServerPrototype{}
-						for _, manualServersItem := range newResolverManualServers.([]interface{}) {
+						for _, manualServersItem := range newResolverManualServers.(*schema.Set).List() {
 							manualServersItemModel, err := resourceIBMIsVPCMapToDnsServerPrototype(manualServersItem.(map[string]interface{}))
 							if err != nil {
 								return err
@@ -1513,6 +1516,14 @@ func suppressNullVPC(k, old, new string, d *schema.ResourceData) bool {
 	return false
 }
 
+func hashManualServersList(v interface{}) int {
+	var buf bytes.Buffer
+	a := v.(map[string]interface{})
+	buf.WriteString(fmt.Sprintf("%s-", a["address"].(string)))
+	buf.WriteString(fmt.Sprintf("%s-", a["zone_affinity"].(string)))
+	return conns.String(buf.String())
+}
+
 // for create dns
 func resourceIBMIsVPCMapToVpcdnsPrototype(modelMap map[string]interface{}) (*vpcv1.VpcdnsPrototype, error) {
 	model := &vpcv1.VpcdnsPrototype{}
@@ -1537,7 +1548,7 @@ func resourceIBMIsVPCMapToVpcdnsResolverPrototype(modelMap map[string]interface{
 	if modelMap["manual_servers"] != nil {
 		model.Type = core.StringPtr("manual")
 		manualServers := []vpcv1.DnsServerPrototype{}
-		for _, manualServersItem := range modelMap["manual_servers"].([]interface{}) {
+		for _, manualServersItem := range modelMap["manual_servers"].(*schema.Set).List() {
 			manualServersItemModel, err := resourceIBMIsVPCMapToDnsServerPrototype(manualServersItem.(map[string]interface{}))
 			if err != nil {
 				return model, err
diff --git a/ibm/service/vpc/resource_ibm_is_vpc_test.go b/ibm/service/vpc/resource_ibm_is_vpc_test.go
index cb84d99271..6f9cc88a66 100644
--- a/ibm/service/vpc/resource_ibm_is_vpc_test.go
+++ b/ibm/service/vpc/resource_ibm_is_vpc_test.go
@@ -97,8 +97,6 @@ func TestAccIBMISVPC_dns_manual(t *testing.T) {
 						"ibm_is_vpc.testacc_vpc1", "dns.0.resolver.0.servers.#"),
 					resource.TestCheckResourceAttr(
 						"ibm_is_vpc.testacc_vpc1", "dns.0.resolver.0.servers.#", "1"),
-					resource.TestCheckResourceAttr(
-						"ibm_is_vpc.testacc_vpc1", "dns.0.resolver.0.manual_servers.0.address", server1Add),
 				),
 			},
 			{