fix: Improve error message when networking peering reaches a failed status

.changelog/2766.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/mongodbatlas_network_peering: Improve error message when networking peering reaches a failed status
+```

internal/service/networkpeering/resource_network_peering.go

@@ -247,7 +247,7 @@ func resourceCreate(ctx context.Context, d *schema.ResourceData, meta any) diag.
 
 	stateConf := &retry.StateChangeConf{
 		Pending:    []string{"INITIATING", "FINALIZING", "ADDING_PEER", "WAITING_FOR_USER"},
-		Target:     []string{"AVAILABLE", "PENDING_ACCEPTANCE"},
+		Target:     []string{"FAILED", "AVAILABLE", "PENDING_ACCEPTANCE"},
 		Refresh:    resourceRefreshFunc(ctx, peer.GetId(), projectID, peerRequest.GetContainerId(), conn.NetworkPeeringApi),
 		Timeout:    1 * time.Hour,
 		MinTimeout: 10 * time.Second,
@@ -313,7 +313,24 @@ func resourceRead(ctx context.Context, d *schema.ResourceData, meta any) diag.Di
 	if err != nil {
 		return diag.FromErr(err)
 	}
-	return setCommonFields(d, peer, peerID, accepterRegionName)
+
+	diags := setCommonFields(d, peer, peerID, accepterRegionName)
+
+	failedStatusDiag := errorIfFailedStatusIsPresent(peer)
+
+	return append(diags, failedStatusDiag...)
+}
+
+func errorIfFailedStatusIsPresent(peer *admin.BaseNetworkPeeringConnectionSettings) diag.Diagnostics {
+	// for Azure/GCP "status" and "errorState" is returned, for AWS "statusName" and "errorStateName" :-/
+	if peer.GetStatus() == "FAILED" || peer.GetStatusName() == "FAILED" {
+		errorState := peer.GetErrorState()
+		if peer.GetErrorStateName() != "" {
+			errorState = peer.GetErrorStateName()
+		}
+		return diag.FromErr(fmt.Errorf("peer networking is in a failed state: %s", errorState))
+	}
+	return nil
 }
 
 func setCommonFields(d *schema.ResourceData, peer *admin.BaseNetworkPeeringConnectionSettings, peerID, accepterRegionName string) diag.Diagnostics {
@@ -440,7 +457,7 @@ func resourceUpdate(ctx context.Context, d *schema.ResourceData, meta any) diag.
 
 	stateConf := &retry.StateChangeConf{
 		Pending:    []string{"INITIATING", "FINALIZING", "ADDING_PEER", "WAITING_FOR_USER"},
-		Target:     []string{"AVAILABLE", "PENDING_ACCEPTANCE"},
+		Target:     []string{"FAILED", "AVAILABLE", "PENDING_ACCEPTANCE"},
 		Refresh:    resourceRefreshFunc(ctx, peerID, projectID, "", conn.NetworkPeeringApi),
 		Timeout:    d.Timeout(schema.TimeoutCreate),
 		MinTimeout: 30 * time.Second,

internal/service/networkpeering/resource_network_peering_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -74,6 +75,28 @@ func TestAccNetworkRSNetworkPeering_Azure(t *testing.T) {
 	})
 }
 
+func TestAccNetworkRSNetworkPeering_AzureFailedStatus(t *testing.T) {
+	var (
+		directoryID       = os.Getenv("AZURE_DIRECTORY_ID")
+		subscriptionID    = os.Getenv("AZURE_SUBSCRIPTION_ID")
+		resourceGroupName = os.Getenv("AZURE_RESOURCE_GROUP_NAME")
+		vNetName          = os.Getenv("AZURE_VNET_NAME")
+		providerName      = "AZURE"
+	)
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:                 func() { acc.PreCheckBasic(t); acc.PreCheckPeeringEnvAzure(t) },
+		ProtoV6ProviderFactories: acc.TestAccProviderV6Factories,
+		CheckDestroy:             acc.CheckDestroyNetworkPeering,
+		Steps: []resource.TestStep{
+			{
+				Config:      configAzureTwoPeeringSameCIDR(providerName, directoryID, subscriptionID, resourceGroupName, vNetName),
+				ExpectError: regexp.MustCompile("peer networking is in a failed state:"),
+			},
+		},
+	})
+}
+
 func TestAccNetworkRSNetworkPeering_GCP(t *testing.T) {
 	acc.SkipTestForCI(t) // needs GCP configuration
 
@@ -312,6 +335,45 @@ func configAzure(projectID, providerName, directoryID, subscriptionID, resourceG
 	`, projectID, providerName, directoryID, subscriptionID, resourceGroupName, vNetName)
 }
 
+func configAzureTwoPeeringSameCIDR(providerName, directoryID, subscriptionID, resourceGroupName, vNetName string) string {
+	orgID := os.Getenv("MONGODB_ATLAS_ORG_ID")
+	firstProjName := acc.RandomProjectName()
+	secondProjName := acc.RandomProjectName()
+	cidrBlock := "172.16.0.0/21" // failure expected as 2 peering connections use same cidr block range in same azure account
+	firstAzureConfig := configAzureWithProject("first", orgID, firstProjName, cidrBlock, providerName, directoryID, subscriptionID, resourceGroupName, vNetName)
+	secondAzureConfig := configAzureWithProject("second", orgID, secondProjName, cidrBlock, providerName, directoryID, subscriptionID, resourceGroupName, vNetName)
+	return fmt.Sprintf(`
+		%[1]s
+		%[2]s
+	`, firstAzureConfig, secondAzureConfig)
+}
+
+func configAzureWithProject(rsName, orgID, projectName, cidrBlock, providerName, directoryID, subscriptionID, resourceGroupName, vNetName string) string {
+	return fmt.Sprintf(`
+		resource "mongodbatlas_project" "%[8]s" {
+			org_id 			 = %[1]q
+			name   			 = %[2]q
+		}
+
+		resource "mongodbatlas_network_container" "%[8]s" {
+			project_id   		  = mongodbatlas_project.%[8]s.id
+			atlas_cidr_block  = %[9]q
+			provider_name		  = %[3]q
+			region    			  = "US_EAST_2"
+		}
+
+		resource "mongodbatlas_network_peering" "%[8]s" {
+			project_id   		  = mongodbatlas_project.%[8]s.id
+			container_id          = mongodbatlas_network_container.%[8]s.container_id
+			provider_name         = %[3]q
+			azure_directory_id    = %[4]q
+			azure_subscription_id = %[5]q
+			resource_group_name   = %[6]q
+			vnet_name	          = %[7]q
+		}
+	`, orgID, projectName, providerName, directoryID, subscriptionID, resourceGroupName, vNetName, rsName, cidrBlock)
+}
+
 func configGCP(projectID, providerName, gcpProjectID, networkName string) string {
 	return fmt.Sprintf(`
 		resource "mongodbatlas_network_container" "test" {