billingbudget: make threshold optional

.changelog/6259.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+billingbudget: made `thresholdRules` optional in `google_billing_budget`
+```

google/resource_billing_budget.go

@@ -125,31 +125,6 @@ is "USD", then 1 unit is one US dollar.`,
 				ForceNew:    true,
 				Description: `ID of the billing account to set a budget on.`,
 			},
-			"threshold_rules": {
-				Type:     schema.TypeList,
-				Required: true,
-				Description: `Rules that trigger alerts (notifications of thresholds being
-crossed) when spend exceeds the specified percentages of the
-budget.`,
-				Elem: &schema.Resource{
-					Schema: map[string]*schema.Schema{
-						"threshold_percent": {
-							Type:     schema.TypeFloat,
-							Required: true,
-							Description: `Send an alert when this threshold is exceeded. This is a
-1.0-based percentage, so 0.5 = 50%. Must be >= 0.`,
-						},
-						"spend_basis": {
-							Type:         schema.TypeString,
-							Optional:     true,
-							ValidateFunc: validateEnum([]string{"CURRENT_SPEND", "FORECASTED_SPEND", ""}),
-							Description: `The type of basis used to determine if spend has passed
-the threshold. Default value: "CURRENT_SPEND" Possible values: ["CURRENT_SPEND", "FORECASTED_SPEND"]`,
-							Default: "CURRENT_SPEND",
-						},
-					},
-				},
-			},
 			"all_updates_rule": {
 				Type:     schema.TypeList,
 				Optional: true,
@@ -175,6 +150,7 @@ Account Users IAM roles for the target account.`,
 channel in the form
 projects/{project_id}/notificationChannels/{channel_id}.
 A maximum of 5 channels are allowed.`,
+							MaxItems: 5,
 							Elem: &schema.Schema{
 								Type: schema.TypeString,
 							},
@@ -374,6 +350,31 @@ account and all subaccounts, if they exist.`,
 				Optional:    true,
 				Description: `User data for display name in UI. Must be <= 60 chars.`,
 			},
+			"threshold_rules": {
+				Type:     schema.TypeList,
+				Optional: true,
+				Description: `Rules that trigger alerts (notifications of thresholds being
+crossed) when spend exceeds the specified percentages of the
+budget.`,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"threshold_percent": {
+							Type:     schema.TypeFloat,
+							Required: true,
+							Description: `Send an alert when this threshold is exceeded. This is a
+1.0-based percentage, so 0.5 = 50%. Must be >= 0.`,
+						},
+						"spend_basis": {
+							Type:         schema.TypeString,
+							Optional:     true,
+							ValidateFunc: validateEnum([]string{"CURRENT_SPEND", "FORECASTED_SPEND", ""}),
+							Description: `The type of basis used to determine if spend has passed
+the threshold. Default value: "CURRENT_SPEND" Possible values: ["CURRENT_SPEND", "FORECASTED_SPEND"]`,
+							Default: "CURRENT_SPEND",
+						},
+					},
+				},
+			},
 			"name": {
 				Type:     schema.TypeString,
 				Computed: true,

google/resource_billing_budget_generated_test.go

@@ -343,6 +343,61 @@ resource "google_billing_budget" "budget" {
 `, context)
 }
 
+func TestAccBillingBudget_billingBudgetOptionalExample(t *testing.T) {
+	t.Parallel()
+
+	context := map[string]interface{}{
+		"billing_acct":  getTestBillingAccountFromEnv(t),
+		"random_suffix": randString(t, 10),
+	}
+
+	vcrTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckBillingBudgetDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccBillingBudget_billingBudgetOptionalExample(context),
+			},
+			{
+				ResourceName:            "google_billing_budget.budget",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"billing_account"},
+			},
+		},
+	})
+}
+
+func testAccBillingBudget_billingBudgetOptionalExample(context map[string]interface{}) string {
+	return Nprintf(`
+data "google_billing_account" "account" {
+  billing_account = "%{billing_acct}"
+}
+
+resource "google_billing_budget" "budget" {
+  billing_account = data.google_billing_account.account.id
+  display_name = "Example Billing Budget%{random_suffix}"
+
+  amount {
+    specified_amount {
+      currency_code = "USD"
+      units = "100000"
+    }
+  }
+
+  all_updates_rule {
+    disable_default_iam_recipients = true
+    pubsub_topic = google_pubsub_topic.budget.id
+  }
+}
+
+resource "google_pubsub_topic" "budget" {
+  name = "tf-test-example-topic%{random_suffix}"
+}
+`, context)
+}
+
 func testAccCheckBillingBudgetDestroyProducer(t *testing.T) func(s *terraform.State) error {
 	return func(s *terraform.State) error {
 		for name, rs := range s.RootModule().Resources {

website/docs/r/billing_budget.html.markdown

@@ -238,13 +238,6 @@ The following arguments are supported:
   The budgeted amount for each usage period.
   Structure is [documented below](#nested_amount).
 
-* `threshold_rules` -
-  (Required)
-  Rules that trigger alerts (notifications of thresholds being
-  crossed) when spend exceeds the specified percentages of the
-  budget.
-  Structure is [documented below](#nested_threshold_rules).
-
 * `billing_account` -
   (Required)
   ID of the billing account to set a budget on.
@@ -288,20 +281,6 @@ The following arguments are supported:
   zero. For example $-1.75 is represented as units=-1 and
   nanos=-750,000,000.
 
-<a name="nested_threshold_rules"></a>The `threshold_rules` block supports:
-
-* `threshold_percent` -
-  (Required)
-  Send an alert when this threshold is exceeded. This is a
-  1.0-based percentage, so 0.5 = 50%. Must be >= 0.
-
-* `spend_basis` -
-  (Optional)
-  The type of basis used to determine if spend has passed
-  the threshold.
-  Default value is `CURRENT_SPEND`.
-  Possible values are `CURRENT_SPEND` and `FORECASTED_SPEND`.
-
 - - -
 
 
@@ -315,6 +294,13 @@ The following arguments are supported:
   spend against the budget.
   Structure is [documented below](#nested_budget_filter).
 
+* `threshold_rules` -
+  (Optional)
+  Rules that trigger alerts (notifications of thresholds being
+  crossed) when spend exceeds the specified percentages of the
+  budget.
+  Structure is [documented below](#nested_threshold_rules).
+
 * `all_updates_rule` -
   (Optional)
   Defines notifications that are sent on every update to the
@@ -427,6 +413,20 @@ The following arguments are supported:
   (Required)
   Day of a month. Must be from 1 to 31 and valid for the year and month.
 
+<a name="nested_threshold_rules"></a>The `threshold_rules` block supports:
+
+* `threshold_percent` -
+  (Required)
+  Send an alert when this threshold is exceeded. This is a
+  1.0-based percentage, so 0.5 = 50%. Must be >= 0.
+
+* `spend_basis` -
+  (Optional)
+  The type of basis used to determine if spend has passed
+  the threshold.
+  Default value is `CURRENT_SPEND`.
+  Possible values are `CURRENT_SPEND` and `FORECASTED_SPEND`.
+
 <a name="nested_all_updates_rule"></a>The `all_updates_rule` block supports:
 
 * `pubsub_topic` -