settings file is not required

builtin/providers/azure/provider.go

@@ -17,7 +17,7 @@ func Provider() terraform.ResourceProvider {
 		Schema: map[string]*schema.Schema{
 			"settings_file": &schema.Schema{
 				Type:         schema.TypeString,
-				Required:     true,
+				Optional:     true,
 				DefaultFunc:  schema.EnvDefaultFunc("AZURE_SETTINGS_FILE", nil),
 				ValidateFunc: validateSettingsFile,
 			},

website/source/docs/providers/azure/index.html.markdown

@@ -33,7 +33,7 @@ resource "azure_instance" "web" {
 
 The following arguments are supported:
 
-* `settings_file` - (Required) Contents of a valid `publishsettings` file, used to
+* `settings_file` - (Optional) Contents of a valid `publishsettings` file, used to
   authenticate with the Azure API. You can download the settings file here:
   https://manage.windowsazure.com/publishsettings. You must either provide
   (or source from the `AZURE_SETTINGS_FILE` environment variable) a settings