Add ability to turn off subscription key in API Management API

- Fixes hashicorp#4884

azurerm/resource_arm_api_management_api.go

@@ -159,6 +159,21 @@ func resourceArmApiManagementApi() *schema.Resource {
 				},
 			},
 
+			"authentication_settings": {
+				Type:     schema.TypeList,
+				Optional: true,
+				Computed: true,
+				MaxItems: 1,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"subscription_key_required": {
+							Type:     schema.TypeBool,
+							Required: true,
+						},
+					},
+				},
+			},
+
 			"soap_pass_through": {
 				Type:     schema.TypeBool,
 				Optional: true,
@@ -266,6 +281,9 @@ func resourceArmApiManagementApiCreateUpdate(d *schema.ResourceData, meta interf
 	subscriptionKeyParameterNamesRaw := d.Get("subscription_key_parameter_names").([]interface{})
 	subscriptionKeyParameterNames := expandApiManagementApiSubscriptionKeyParamNames(subscriptionKeyParameterNamesRaw)
 
+	authenticationSettingsRaw := d.Get("auhtentication_settings").([]interface{})
+	authenticationSettings := expandApiManagementAuthenticationSettings(authenticationSettingsRaw)
+
 	var apiType apimanagement.APIType
 	soapPassThrough := d.Get("soap_pass_through").(bool)
 	if soapPassThrough {
@@ -284,6 +302,7 @@ func resourceArmApiManagementApiCreateUpdate(d *schema.ResourceData, meta interf
 			ServiceURL:                    utils.String(serviceUrl),
 			SubscriptionKeyParameterNames: subscriptionKeyParameterNames,
 			APIVersion:                    utils.String(version),
+			AuthenticationSettings:        authenticationSettings,
 		},
 	}
 
@@ -363,6 +382,10 @@ func resourceArmApiManagementApiRead(d *schema.ResourceData, meta interface{}) e
 		if err := d.Set("subscription_key_parameter_names", flattenApiManagementApiSubscriptionKeyParamNames(props.SubscriptionKeyParameterNames)); err != nil {
 			return fmt.Errorf("Error setting `subscription_key_parameter_names`: %+v", err)
 		}
+
+		if err := d.Set("authentication_settings", flattenApiManagementAuthenticationSettings(props.AuthenticationSettings)); err != nil {
+			return fmt.Errorf("Error setting `authentication_settings`: %+v", err)
+		}
 	}
 
 	return nil
@@ -454,3 +477,30 @@ func flattenApiManagementApiSubscriptionKeyParamNames(paramNames *apimanagement.
 
 	return []interface{}{result}
 }
+
+func expandApiManagementAuthenticationSettings(input []interface{}) *apimanagement.AuthenticationSettingsContract {
+	if len(input) == 0 {
+		return nil
+	}
+
+	v := input[0].(map[string]interface{})
+	subscriptionKeyRequired := v["subscriptionKeyRequired"].(bool)
+	contract := apimanagement.AuthenticationSettingsContract{
+		SubscriptionKeyRequired: utils.Bool(subscriptionKeyRequired),
+	}
+	return &contract
+}
+
+func flattenApiManagementAuthenticationSettings(paramNames *apimanagement.AuthenticationSettingsContract) []interface{} {
+	if paramNames == nil {
+		return make([]interface{}, 0)
+	}
+
+	result := make(map[string]interface{})
+
+	if paramNames.SubscriptionKeyRequired != nil {
+		result["subscription_key_required"] = *paramNames.SubscriptionKeyRequired
+	}
+
+	return []interface{}{result}
+}

azurerm/resource_arm_api_management_api_test.go

@@ -517,6 +517,10 @@ resource "azurerm_api_management_api" "test" {
     header = "X-Butter-Robot-API-Key"
     query  = "location"
   }
+  
+  authentication_settings {
+	subscription_key_required = false
+ }
 }
 `, template, rInt)
 }

website/docs/d/api_management_api.html.markdown

@@ -58,12 +58,20 @@ output "api_management_api_id" {
 
 * `subscription_key_parameter_names` - A `subscription_key_parameter_names` block as documented below.
 
+* `authentication_settings` - An `authentication_settings` block as documented below.
+
 * `version` - The Version number of this API, if this API is versioned.
 
 * `version_set_id` - The ID of the Version Set which this API is associated with.
 
 ---
 
+An `authentication_settings` block exports the following:
+
+* `subscription_key_required` - Should this API require a subscription key?
+
+---
+
 A `subscription_key_parameter_names` block exports the following:
 
 * `header` - The name of the HTTP Header which should be used for the Subscription Key.