provider/azurerm: VM Scale Sets - import support + fixes (#13464)

* Ensuring we base64 decode the custom data if it's base64 encoded

* Import support for VM Scale Sets

* Updating the docs to mention Import support

* Fixes #13009, where the SSH Keys would be set at the incorrect index

(leaving a null entry at the start, causing a crash on the second apply)

* Adding tests to cover the updating use-case

* Adding an import linux test

* Storing the base64 encoded value
Making custom_data a force new, since it an't be updated

* Updating the docs

builtin/providers/azurerm/import_arm_virtual_machine_scale_set_test.go

@@ -0,0 +1,135 @@
+package azurerm
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/terraform/helper/acctest"
+	"github.com/hashicorp/terraform/helper/resource"
+)
+
+func TestAccAzureRMVirtualMachineScaleSet_importBasic(t *testing.T) {
+	resourceName := "azurerm_virtual_machine_scale_set.test"
+
+	ri := acctest.RandInt()
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSet_basic, ri, ri, ri, ri, ri, ri, ri, ri)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+			},
+			{
+				ResourceName:      resourceName,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
+func TestAccAzureRMVirtualMachineScaleSet_importLinux(t *testing.T) {
+	resourceName := "azurerm_virtual_machine_scale_set.test"
+
+	ri := acctest.RandInt()
+	config := testAccAzureRMVirtualMachineScaleSet_linux(ri)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+			},
+			{
+				ResourceName:      resourceName,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
+func TestAccAzureRMVirtualMachineScaleSet_importLoadBalancer(t *testing.T) {
+	resourceName := "azurerm_virtual_machine_scale_set.test"
+
+	ri := acctest.RandInt()
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSetLoadbalancerTemplate, ri, ri, ri, ri, ri, ri, ri)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+			},
+			{
+				ResourceName:      resourceName,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
+func TestAccAzureRMVirtualMachineScaleSet_importOverProvision(t *testing.T) {
+	ri := acctest.RandInt()
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSetOverprovisionTemplate, ri, ri, ri, ri, ri, ri)
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMVirtualMachineScaleSetExists("azurerm_virtual_machine_scale_set.test"),
+					testCheckAzureRMVirtualMachineScaleSetOverprovision("azurerm_virtual_machine_scale_set.test"),
+				),
+			},
+		},
+	})
+}
+
+func TestAccAzureRMVirtualMachineScaleSet_importExtension(t *testing.T) {
+	ri := acctest.RandInt()
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSetExtensionTemplate, ri, ri, ri, ri, ri, ri)
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMVirtualMachineScaleSetExists("azurerm_virtual_machine_scale_set.test"),
+					testCheckAzureRMVirtualMachineScaleSetExtension("azurerm_virtual_machine_scale_set.test"),
+				),
+			},
+		},
+	})
+}
+
+func TestAccAzureRMVirtualMachineScaleSet_importMultipleExtensions(t *testing.T) {
+	ri := acctest.RandInt()
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSetMultipleExtensionsTemplate, ri, ri, ri, ri, ri, ri)
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMVirtualMachineScaleSetExists("azurerm_virtual_machine_scale_set.test"),
+					testCheckAzureRMVirtualMachineScaleSetExtension("azurerm_virtual_machine_scale_set.test"),
+				),
+			},
+		},
+	})
+}

builtin/providers/azurerm/provider.go

@@ -346,7 +346,7 @@ func userDataStateFunc(v interface{}) string {
 	}
 }
 
-// Base64Encode encodes data if the input isn't already encoded using
+// base64Encode encodes data if the input isn't already encoded using
 // base64.StdEncoding.EncodeToString. If the input is already base64 encoded,
 // return the original input unchanged.
 func base64Encode(data string) string {

builtin/providers/azurerm/resource_arm_virtual_machine_scale_set.go

@@ -19,6 +19,9 @@ func resourceArmVirtualMachineScaleSet() *schema.Resource {
 		Read:   resourceArmVirtualMachineScaleSetRead,
 		Update: resourceArmVirtualMachineScaleSetCreate,
 		Delete: resourceArmVirtualMachineScaleSetDelete,
+		Importer: &schema.ResourceImporter{
+			State: schema.ImportStatePassthrough,
+		},
 
 		Schema: map[string]*schema.Schema{
 			"name": {
@@ -96,6 +99,7 @@ func resourceArmVirtualMachineScaleSet() *schema.Resource {
 						"custom_data": {
 							Type:      schema.TypeString,
 							Optional:  true,
+							ForceNew:  true,
 							StateFunc: userDataStateFunc,
 						},
 					},
@@ -497,8 +501,9 @@ func resourceArmVirtualMachineScaleSetRead(d *schema.ResourceData, meta interfac
 		return fmt.Errorf("Error making Read request on Azure Virtual Machine Scale Set %s: %s", name, err)
 	}
 
-	d.Set("location", resp.Location)
 	d.Set("name", resp.Name)
+	d.Set("resource_group_name", resGroup)
+	d.Set("location", azureRMNormalizeLocation(*resp.Location))
 
 	if err := d.Set("sku", flattenAzureRmVirtualMachineScaleSetSku(resp.Sku)); err != nil {
 		return fmt.Errorf("[DEBUG] Error setting Virtual Machine Scale Set Sku error: %#v", err)
@@ -509,7 +514,12 @@ func resourceArmVirtualMachineScaleSetRead(d *schema.ResourceData, meta interfac
 	d.Set("upgrade_policy_mode", properties.UpgradePolicy.Mode)
 	d.Set("overprovision", properties.Overprovision)
 
-	if err := d.Set("os_profile", flattenAzureRMVirtualMachineScaleSetOsProfile(properties.VirtualMachineProfile.OsProfile)); err != nil {
+	osProfile, err := flattenAzureRMVirtualMachineScaleSetOsProfile(properties.VirtualMachineProfile.OsProfile)
+	if err != nil {
+		return fmt.Errorf("[DEBUG] Error flattening Virtual Machine Scale Set OS Profile. Error: %#v", err)
+	}
+
+	if err := d.Set("os_profile", osProfile); err != nil {
 		return fmt.Errorf("[DEBUG] Error setting Virtual Machine Scale Set OS Profile error: %#v", err)
 	}
 
@@ -578,7 +588,7 @@ func flattenAzureRmVirtualMachineScaleSetOsProfileLinuxConfig(config *compute.Li
 	result["disable_password_authentication"] = *config.DisablePasswordAuthentication
 
 	if config.SSH != nil && len(*config.SSH.PublicKeys) > 0 {
-		ssh_keys := make([]map[string]interface{}, len(*config.SSH.PublicKeys))
+		ssh_keys := make([]map[string]interface{}, 0, len(*config.SSH.PublicKeys))
 		for _, i := range *config.SSH.PublicKeys {
 			key := make(map[string]interface{})
 			key["path"] = *i.Path
@@ -710,7 +720,7 @@ func flattenAzureRmVirtualMachineScaleSetNetworkProfile(profile *compute.Virtual
 	return result
 }
 
-func flattenAzureRMVirtualMachineScaleSetOsProfile(profile *compute.VirtualMachineScaleSetOSProfile) []interface{} {
+func flattenAzureRMVirtualMachineScaleSetOsProfile(profile *compute.VirtualMachineScaleSetOSProfile) ([]interface{}, error) {
 	result := make(map[string]interface{})
 
 	result["computer_name_prefix"] = *profile.ComputerNamePrefix
@@ -720,7 +730,7 @@ func flattenAzureRMVirtualMachineScaleSetOsProfile(profile *compute.VirtualMachi
 		result["custom_data"] = *profile.CustomData
 	}
 
-	return []interface{}{result}
+	return []interface{}{result}, nil
 }
 
 func flattenAzureRmVirtualMachineScaleSetStorageProfileOSDisk(profile *compute.VirtualMachineScaleSetOSDisk) []interface{} {
@@ -849,7 +859,11 @@ func resourceArmVirtualMachineScaleSetsOsProfileHash(v interface{}) int {
 	buf.WriteString(fmt.Sprintf("%s-", m["computer_name_prefix"].(string)))
 	buf.WriteString(fmt.Sprintf("%s-", m["admin_username"].(string)))
 	if m["custom_data"] != nil {
-		buf.WriteString(fmt.Sprintf("%s-", m["custom_data"].(string)))
+		customData := m["custom_data"].(string)
+		if !isBase64Encoded(customData) {
+			customData = base64Encode(customData)
+		}
+		buf.WriteString(fmt.Sprintf("%s-", customData))
 	}
 	return hashcode.String(buf.String())
 }
@@ -1076,12 +1090,12 @@ func expandAzureRmVirtualMachineScaleSetOsProfileLinuxConfig(d *schema.ResourceD
 	linuxConfig := osProfilesLinuxConfig[0].(map[string]interface{})
 	disablePasswordAuth := linuxConfig["disable_password_authentication"].(bool)
 
-	config := &compute.LinuxConfiguration{
-		DisablePasswordAuthentication: &disablePasswordAuth,
-	}
 	linuxKeys := linuxConfig["ssh_keys"].([]interface{})
 	sshPublicKeys := make([]compute.SSHPublicKey, 0, len(linuxKeys))
 	for _, key := range linuxKeys {
+		if key == nil {
+			continue
+		}
 		sshKey := key.(map[string]interface{})
 		path := sshKey["path"].(string)
 		keyData := sshKey["key_data"].(string)
@@ -1094,8 +1108,11 @@ func expandAzureRmVirtualMachineScaleSetOsProfileLinuxConfig(d *schema.ResourceD
 		sshPublicKeys = append(sshPublicKeys, sshPublicKey)
 	}
 
-	config.SSH = &compute.SSHConfiguration{
+	config := &compute.LinuxConfiguration{
+		DisablePasswordAuthentication: &disablePasswordAuth,
+		SSH: &compute.SSHConfiguration{
 			PublicKeys: &sshPublicKeys,
+		},
 	}
 
 	return config, nil

builtin/providers/azurerm/resource_arm_virtual_machine_scale_set_test.go

@@ -10,9 +10,9 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
-func TestAccAzureRMVirtualMachineScaleSet_basicLinux(t *testing.T) {
+func TestAccAzureRMVirtualMachineScaleSet_basic(t *testing.T) {
 	ri := acctest.RandInt()
-	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSet_basicLinux, ri, ri, ri, ri, ri, ri, ri, ri)
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSet_basic, ri, ri, ri, ri, ri, ri, ri, ri)
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
@@ -28,9 +28,36 @@ func TestAccAzureRMVirtualMachineScaleSet_basicLinux(t *testing.T) {
 	})
 }
 
+func TestAccAzureRMVirtualMachineScaleSet_linuxUpdated(t *testing.T) {
+	resourceName := "azurerm_virtual_machine_scale_set.test"
+	ri := acctest.RandInt()
+	config := testAccAzureRMVirtualMachineScaleSet_linux(ri)
+	updatedConfig := testAccAzureRMVirtualMachineScaleSet_linuxUpdated(ri)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testCheckAzureRMVirtualMachineScaleSetDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: config,
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMVirtualMachineScaleSetExists(resourceName),
+				),
+			},
+			{
+				Config: updatedConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMVirtualMachineScaleSetExists(resourceName),
+				),
+			},
+		},
+	})
+}
+
 func TestAccAzureRMVirtualMachineScaleSet_basicLinux_disappears(t *testing.T) {
 	ri := acctest.RandInt()
-	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSet_basicLinux, ri, ri, ri, ri, ri, ri, ri, ri)
+	config := fmt.Sprintf(testAccAzureRMVirtualMachineScaleSet_basic, ri, ri, ri, ri, ri, ri, ri, ri)
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
@@ -311,7 +338,7 @@ func testCheckAzureRMVirtualMachineScaleSetExtension(name string) resource.TestC
 	}
 }
 
-var testAccAzureRMVirtualMachineScaleSet_basicLinux = `
+var testAccAzureRMVirtualMachineScaleSet_basic = `
 resource "azurerm_resource_group" "test" {
   name     = "acctestRG-%d"
   location = "West US"
@@ -382,6 +409,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
   network_profile {
     name    = "TestNetworkProfile-%d"
     primary = true
+
     ip_configuration {
       name      = "TestIPConfiguration"
       subnet_id = "${azurerm_subnet.test.id}"
@@ -404,6 +432,244 @@ resource "azurerm_virtual_machine_scale_set" "test" {
 }
 `
 
+func testAccAzureRMVirtualMachineScaleSet_linux(rInt int) string {
+	return fmt.Sprintf(`
+	resource "azurerm_resource_group" "test" {
+  name     = "acctestrg-%d"
+  location = "West Europe"
+}
+
+resource "azurerm_virtual_network" "test" {
+  name                = "acctestvn-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  address_space       = ["10.0.0.0/8"]
+}
+
+resource "azurerm_subnet" "test" {
+  name                 = "acctestsn-%d"
+  resource_group_name  = "${azurerm_resource_group.test.name}"
+  virtual_network_name = "${azurerm_virtual_network.test.name}"
+  address_prefix       = "10.0.1.0/24"
+}
+
+resource "azurerm_storage_account" "test" {
+  name                = "accsa%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  account_type        = "Standard_LRS"
+}
+
+resource "azurerm_storage_container" "test" {
+  name                  = "acctestsc-%d"
+  resource_group_name   = "${azurerm_resource_group.test.name}"
+  storage_account_name  = "${azurerm_storage_account.test.name}"
+  container_access_type = "private"
+}
+
+resource "azurerm_public_ip" "test" {
+  name                         = "acctestpip-%d"
+  resource_group_name          = "${azurerm_resource_group.test.name}"
+  location                     = "${azurerm_resource_group.test.location}"
+  public_ip_address_allocation = "static"
+}
+
+resource "azurerm_lb" "test" {
+  name                = "acctestlb-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+
+  frontend_ip_configuration {
+    name                 = "ip-address"
+    public_ip_address_id = "${azurerm_public_ip.test.id}"
+  }
+}
+
+resource "azurerm_lb_backend_address_pool" "test" {
+  name                = "acctestbap-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  loadbalancer_id     = "${azurerm_lb.test.id}"
+}
+
+resource "azurerm_virtual_machine_scale_set" "test" {
+  name                = "acctestvmss-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  upgrade_policy_mode = "Automatic"
+
+  sku {
+    name     = "Standard_A0"
+    tier     = "Standard"
+    capacity = "1"
+  }
+
+  os_profile {
+    computer_name_prefix = "prefix"
+    admin_username       = "ubuntu"
+    admin_password       = "password"
+    custom_data          = "custom data!"
+  }
+
+  os_profile_linux_config {
+    disable_password_authentication = true
+
+    ssh_keys {
+      path     = "/home/ubuntu/.ssh/authorized_keys"
+      key_data = "ssh-rsa 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 hello@world.com"
+    }
+  }
+
+  network_profile {
+    name    = "TestNetworkProfile"
+    primary = true
+
+    ip_configuration {
+      name                                   = "TestIPConfiguration"
+      subnet_id                              = "${azurerm_subnet.test.id}"
+      load_balancer_backend_address_pool_ids = ["${azurerm_lb_backend_address_pool.test.id}"]
+    }
+  }
+
+  storage_profile_os_disk {
+    name           = "osDiskProfile"
+    caching        = "ReadWrite"
+    create_option  = "FromImage"
+    os_type        = "linux"
+    vhd_containers = ["${azurerm_storage_account.test.primary_blob_endpoint}${azurerm_storage_container.test.name}"]
+  }
+
+  storage_profile_image_reference {
+    publisher = "Canonical"
+    offer     = "UbuntuServer"
+    sku       = "14.04.2-LTS"
+    version   = "latest"
+  }
+}
+
+`, rInt, rInt, rInt, rInt, rInt, rInt, rInt, rInt, rInt)
+}
+
+func testAccAzureRMVirtualMachineScaleSet_linuxUpdated(rInt int) string {
+	return fmt.Sprintf(`
+	resource "azurerm_resource_group" "test" {
+  name     = "acctestrg-%d"
+  location = "West Europe"
+}
+
+resource "azurerm_virtual_network" "test" {
+  name                = "acctestvn-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  address_space       = ["10.0.0.0/8"]
+}
+
+resource "azurerm_subnet" "test" {
+  name                 = "acctestsn-%d"
+  resource_group_name  = "${azurerm_resource_group.test.name}"
+  virtual_network_name = "${azurerm_virtual_network.test.name}"
+  address_prefix       = "10.0.1.0/24"
+}
+
+resource "azurerm_storage_account" "test" {
+  name                = "accsa%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  account_type        = "Standard_LRS"
+}
+
+resource "azurerm_storage_container" "test" {
+  name                  = "acctestsc-%d"
+  resource_group_name   = "${azurerm_resource_group.test.name}"
+  storage_account_name  = "${azurerm_storage_account.test.name}"
+  container_access_type = "private"
+}
+
+resource "azurerm_public_ip" "test" {
+  name                         = "acctestpip-%d"
+  resource_group_name          = "${azurerm_resource_group.test.name}"
+  location                     = "${azurerm_resource_group.test.location}"
+  public_ip_address_allocation = "static"
+}
+
+resource "azurerm_lb" "test" {
+  name                = "acctestlb-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+
+  frontend_ip_configuration {
+    name                 = "ip-address"
+    public_ip_address_id = "${azurerm_public_ip.test.id}"
+  }
+}
+
+resource "azurerm_lb_backend_address_pool" "test" {
+  name                = "acctestbap-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  loadbalancer_id     = "${azurerm_lb.test.id}"
+}
+
+resource "azurerm_virtual_machine_scale_set" "test" {
+  name                = "acctestvmss-%d"
+  resource_group_name = "${azurerm_resource_group.test.name}"
+  location            = "${azurerm_resource_group.test.location}"
+  upgrade_policy_mode = "Automatic"
+
+  sku {
+    name     = "Standard_A0"
+    tier     = "Standard"
+    capacity = "1"
+  }
+
+  os_profile {
+    computer_name_prefix = "prefix"
+    admin_username       = "ubuntu"
+    admin_password       = "password"
+    custom_data          = "custom data!"
+  }
+
+  os_profile_linux_config {
+    disable_password_authentication = true
+
+    ssh_keys {
+      path     = "/home/ubuntu/.ssh/authorized_keys"
+      key_data = "ssh-rsa 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 hello@world.com"
+    }
+  }
+
+  network_profile {
+    name    = "TestNetworkProfile"
+    primary = true
+
+    ip_configuration {
+      name                                   = "TestIPConfiguration"
+      subnet_id                              = "${azurerm_subnet.test.id}"
+      load_balancer_backend_address_pool_ids = ["${azurerm_lb_backend_address_pool.test.id}"]
+    }
+  }
+
+  storage_profile_os_disk {
+    name           = "osDiskProfile"
+    caching        = "ReadWrite"
+    create_option  = "FromImage"
+    os_type        = "linux"
+    vhd_containers = ["${azurerm_storage_account.test.primary_blob_endpoint}${azurerm_storage_container.test.name}"]
+  }
+
+  storage_profile_image_reference {
+    publisher = "Canonical"
+    offer     = "UbuntuServer"
+    sku       = "14.04.2-LTS"
+    version   = "latest"
+  }
+
+  tags {
+    ThisIs = "a test"
+  }
+}
+
+`, rInt, rInt, rInt, rInt, rInt, rInt, rInt, rInt, rInt)
+}
+
 var testAccAzureRMVirtualMachineScaleSetLoadbalancerTemplate = `
 resource "azurerm_resource_group" "test" {
   name     = "acctestrg-%d"
@@ -478,6 +744,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
   network_profile {
     name    = "TestNetworkProfile"
     primary = true
+
     ip_configuration {
       name                                   = "TestIPConfiguration"
       subnet_id                              = "${azurerm_subnet.test.id}"
@@ -557,6 +824,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
   network_profile {
     name    = "TestNetworkProfile"
     primary = true
+
     ip_configuration {
       name      = "TestIPConfiguration"
       subnet_id = "${azurerm_subnet.test.id}"
@@ -635,6 +903,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
   network_profile {
     name    = "TestNetworkProfile"
     primary = true
+
     ip_configuration {
       name      = "TestIPConfiguration"
       subnet_id = "${azurerm_subnet.test.id}"
@@ -661,6 +930,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
     type                       = "CustomScript"
     type_handler_version       = "2.0"
     auto_upgrade_minor_version = true
+
     settings = <<SETTINGS
 		{
 			"commandToExecute": "echo $HOSTNAME"
@@ -675,6 +945,7 @@ SETTINGS
 SETTINGS
   }
 }
+
 `
 
 var testAccAzureRMVirtualMachineScaleSetMultipleExtensionsTemplate = `
@@ -733,6 +1004,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
   network_profile {
     name    = "TestNetworkProfile"
     primary = true
+
     ip_configuration {
       name      = "TestIPConfiguration"
       subnet_id = "${azurerm_subnet.test.id}"
@@ -759,6 +1031,7 @@ resource "azurerm_virtual_machine_scale_set" "test" {
     type                       = "CustomScript"
     type_handler_version       = "2.0"
     auto_upgrade_minor_version = true
+
     settings = <<SETTINGS
 		{
 			"commandToExecute": "echo $HOSTNAME"

website/source/docs/providers/azurerm/r/virtual_machine_scale_sets.html.markdown

@@ -140,7 +140,7 @@ The following arguments are supported:
 * `computer_name_prefix` - (Required) Specifies the computer name prefix for all of the virtual machines in the scale set. Computer name prefixes must be 1 to 15 characters long.
 * `admin_username` - (Required) Specifies the administrator account name to use for all the instances of virtual machines in the scale set.
 * `admin_password` - (Required) Specifies the administrator password to use for all the instances of virtual machines in a scale set..
-* `custom_data` - (Optional) Specifies custom data to supply to the machine. On linux-based systems, this can be used as a cloud-init script. On other systems, this will be copied as a file on disk. Internally, Terraform will base64 encode this value before sending it to the API. The maximum length of the binary array is 65535 bytes.
+* `custom_data` - (Optional) Specifies custom data to supply to the machine. On linux-based systems, this can be used as a cloud-init script. On other systems, this will be copied as a file on disk. Internally, Terraform will base64 encode this value before sending it to the API. The maximum length of the binary array is 65535 bytes. Changing this forces a new resource to be created.
 
 `os_profile_secrets` supports the following:
 
@@ -177,7 +177,7 @@ The following arguments are supported:
 * `disable_password_authentication` - (Required) Specifies whether password authentication should be disabled.
 * `ssh_keys` - (Optional) Specifies a collection of `path` and `key_data` to be placed on the virtual machine.
 
-~> **Note:** Please note that the only allowed `path` is `/home/<username>/.ssh/authorized_keys` due to a limitation of Azure_
+~> _**Note:** Please note that the only allowed `path` is `/home/<username>/.ssh/authorized_keys` due to a limitation of Azure_
 
 
 `network_profile` supports the following:
@@ -225,3 +225,12 @@ The following arguments are supported:
 The following attributes are exported:
 
 * `id` - The virtual machine scale set ID.
+
+
+## Import
+
+Virtual Machine Scale Sets can be imported using the `resource id`, e.g.
+
+```
+terraform import azurerm_virtual_machine_scale_set.scaleset1 /subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/mygroup1/providers/Microsoft.Compute/virtualMachineScaleSets/scaleset1
+```