provider/azurerm: arm_virtual_machine diagnostics_profile was causing a

panic on the Read func

Fixes #8995

The Diagnostics profile was a badly laid out resource. All we needed to
set was whether it was enabled and the storage account to save the logs
to. The old schema parameter was deprecated and replaced with a much
simplier structure

```
% make testacc TEST=./builtin/providers/azurerm TESTARGS='-run=TestAccAzureRMVirtualMachine_diagnosticsProfile'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2016/09/29 12:21:04 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/azurerm -v
-run=TestAccAzureRMVirtualMachine_diagnosticsProfile -timeout 120m
=== RUN   TestAccAzureRMVirtualMachine_diagnosticsProfile
--- PASS: TestAccAzureRMVirtualMachine_diagnosticsProfile (1066.76s)
PASS
ok
github.com/hashicorp/terraform/builtin/providers/azurerm1066.776s
```

builtin/providers/azurerm/resource_arm_virtual_machine.go

@@ -11,6 +11,7 @@ import (
 	"github.com/Azure/azure-sdk-for-go/arm/compute"
 	"github.com/hashicorp/terraform/helper/hashcode"
 	"github.com/hashicorp/terraform/helper/schema"
+	riviera "github.com/jen20/riviera/azure"
 )
 
 func resourceArmVirtualMachine() *schema.Resource {
@@ -214,13 +215,15 @@ func resourceArmVirtualMachine() *schema.Resource {
 			},
 
 			"diagnostics_profile": {
-				Type:     schema.TypeSet,
+				Type:     schema.TypeList,
 				Optional: true,
 				MaxItems: 1,
+				ConflictsWith: []string{"boot_diagnostics"},
+				Deprecated:    "Use field boot_diagnostics instead",
 				Elem: &schema.Resource{
 					Schema: map[string]*schema.Schema{
 						"boot_diagnostics": {
-							Type:     schema.TypeSet,
+							Type:     schema.TypeList,
 							Required: true,
 							MaxItems: 1,
 							Elem: &schema.Resource{
@@ -241,6 +244,25 @@ func resourceArmVirtualMachine() *schema.Resource {
 				},
 			},
 
+			"boot_diagnostics": {
+				Type:     schema.TypeList,
+				Optional: true,
+				MaxItems: 1,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"enabled": {
+							Type:     schema.TypeBool,
+							Required: true,
+						},
+
+						"storage_uri": {
+							Type:     schema.TypeString,
+							Required: true,
+						},
+					},
+				},
+			},
+
 			"os_profile": {
 				Type:     schema.TypeSet,
 				Required: true,
@@ -455,7 +477,9 @@ func resourceArmVirtualMachineCreate(d *schema.ResourceData, meta interface{}) e
 
 	if _, ok := d.GetOk("diagnostics_profile"); ok {
 		diagnosticsProfile := expandAzureRmVirtualMachineDiagnosticsProfile(d)
-		properties.DiagnosticsProfile = &diagnosticsProfile
+		if diagnosticsProfile != nil {
+			properties.DiagnosticsProfile = diagnosticsProfile
+		}
 	}
 
 	osProfile, err := expandAzureRmVirtualMachineOsProfile(d)
@@ -751,14 +775,20 @@ func flattenAzureRmVirtualMachineImageReference(image *compute.ImageReference) [
 	return []interface{}{result}
 }
 
-func flattenAzureRmVirtualMachineDiagnosticsProfile(profile *compute.DiagnosticsProfile) map[string]interface{} {
+func flattenAzureRmVirtualMachineDiagnosticsProfile(profile *compute.DiagnosticsProfile) []interface{} {
 	result := make(map[string]interface{})
-	bootDiagnostics := make(map[string]interface{})
-	bootDiagnostics["enabled"] = *profile.BootDiagnostics.Enabled
-	bootDiagnostics["storage_uri"] = *profile.BootDiagnostics.StorageURI
+
+	bootDiagnostics := make([]map[string]interface{}, 0)
+
+	diagnostic := make(map[string]interface{})
+	diagnostic["enabled"] = *profile.BootDiagnostics.Enabled
+	diagnostic["storage_uri"] = *profile.BootDiagnostics.StorageURI
+
+	bootDiagnostics = append(bootDiagnostics, diagnostic)
+
 	result["boot_diagnostics"] = bootDiagnostics
 
-	return result
+	return []interface{}{result}
 }
 
 func flattenAzureRmVirtualMachineNetworkInterfaces(profile *compute.NetworkProfile) []string {
@@ -1140,20 +1170,24 @@ func expandAzureRmVirtualMachineDataDisk(d *schema.ResourceData) ([]compute.Data
 	return data_disks, nil
 }
 
-func expandAzureRmVirtualMachineDiagnosticsProfile(d *schema.ResourceData) compute.DiagnosticsProfile {
-	diagnosticsProfiles := d.Get("diagnostics_profile").(*schema.Set).List()
-	diagnosticsProfile := diagnosticsProfiles[0].(map[string]interface{})
-	bootDiagnosticses := diagnosticsProfile["boot_diagnostics"].(*schema.Set).List()
-	bootDiagnostics := bootDiagnosticses[0].(map[string]interface{})
-	enabled := bootDiagnostics["enabled"].(bool)
-	storageURI := bootDiagnostics["storage_uri"].(string)
-
-	return compute.DiagnosticsProfile{
-		BootDiagnostics: &compute.BootDiagnostics{
-			Enabled:    &enabled,
-			StorageURI: &storageURI,
-		},
+func expandAzureRmVirtualMachineDiagnosticsProfile(d *schema.ResourceData) *compute.DiagnosticsProfile {
+	bootDiagnostics := d.Get("boot_diagnostics").([]interface{})
+
+	diagnosticsProfile := &compute.DiagnosticsProfile{}
+	if len(bootDiagnostics) > 0 {
+		bootDiagnostic := bootDiagnostics[0].(map[string]interface{})
+
+		diagnostic := &compute.BootDiagnostics{
+			Enabled:    riviera.Bool(bootDiagnostic["enabled"].(bool)),
+			StorageURI: riviera.String(bootDiagnostic["storage_uri"].(string)),
+		}
+
+		diagnosticsProfile.BootDiagnostics = diagnostic
+
+		return diagnosticsProfile
 	}
+
+	return nil
 }
 
 func expandAzureRmVirtualMachineImageReference(d *schema.ResourceData) (*compute.ImageReference, error) {

builtin/providers/azurerm/resource_arm_virtual_machine_test.go

@@ -1254,6 +1254,13 @@ resource "azurerm_virtual_machine" "test" {
 	admin_password = "Password1234!"
     }
 
+    diagnostics_profile {
+	boot_diagnostics {
+	    enabled = true
+    	    storage_uri = "${azurerm_storage_account.test.primary_blob_endpoint}"
+	}
+    }
+
     os_profile_windows_config {
         winrm {
 	  protocol = "http"