Addressing the final PR comments.

Author: adcoelho

docs/resources/kibana_alerting_rule.md

@@ -63,11 +63,11 @@ Could not create API key - Unsupported scheme "ApiKey" for granting API Key
 - `actions` (Block List) An action that runs under defined conditions. (see [below for nested schema](#nestedblock--actions))
 - `alert_delay` (Number) A number that indicates how many consecutive runs need to meet the rule conditions for an alert to occur.
 - `enabled` (Boolean) Indicates if you want to run the rule on an interval basis.
-- `notify_when` (String) Deprecated in 8.13.0. Use the `notify_when` property in the action `frequency` object instead. Defines how often alerts generate actions. Valid values include: `onActionGroupChange`: Actions run when the alert status changes; `onActiveAlert`: Actions run when the alert becomes active and at each check interval while the rule conditions are met; `onThrottleInterval`: Actions run when the alert becomes active and at the interval specified in the throttle property while the rule conditions are met. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `notify_when` values.
+- `notify_when` (String) Required until v8.6.0. Deprecated in v8.13.0. Use the `notify_when` property in the action `frequency` object instead. Defines how often alerts generate actions. Valid values include: `onActionGroupChange`: Actions run when the alert status changes; `onActiveAlert`: Actions run when the alert becomes active and at each check interval while the rule conditions are met; `onThrottleInterval`: Actions run when the alert becomes active and at the interval specified in the throttle property while the rule conditions are met. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `notify_when` values.
 - `rule_id` (String) A UUID v1 or v4 to use instead of a randomly generated ID.
 - `space_id` (String) An identifier for the space. If space_id is not provided, the default space is used.
 - `tags` (List of String) A list of tag names that are applied to the rule.
-- `throttle` (String) Defines how often an alert generates repeated actions. This custom action interval must be specified in seconds, minutes, hours, or days. For example, 10m or 1h. This property is applicable only if `notify_when` is `onThrottleInterval`. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `throttle` values.
+- `throttle` (String) Required until v8.6.0. Deprecated in 8.13.0. Defines how often an alert generates repeated actions. This custom action interval must be specified in seconds, minutes, hours, or days. For example, 10m or 1h. This property is applicable only if `notify_when` is `onThrottleInterval`. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `throttle` values.
 
 ### Read-Only
 

internal/kibana/alerting.go

@@ -17,6 +17,8 @@ import (
 )
 
 var alertDelayMinSupportedVersion = version.Must(version.NewVersion("8.13.0"))
+
+// when notify_when and throttle became optional
 var frequencyMinSupportedVersion = version.Must(version.NewVersion("8.6.0"))
 
 func ResourceAlertingRule() *schema.Resource {
@@ -47,7 +49,7 @@ func ResourceAlertingRule() *schema.Resource {
 			ForceNew:    true,
 		},
 		"notify_when": {
-			Description:  "Deprecated in 8.13.0. Use the `notify_when` property in the action `frequency` object instead. Defines how often alerts generate actions. Valid values include: `onActionGroupChange`: Actions run when the alert status changes; `onActiveAlert`: Actions run when the alert becomes active and at each check interval while the rule conditions are met; `onThrottleInterval`: Actions run when the alert becomes active and at the interval specified in the throttle property while the rule conditions are met. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `notify_when` values.",
+			Description:  "Required until v8.6.0. Deprecated in v8.13.0. Use the `notify_when` property in the action `frequency` object instead. Defines how often alerts generate actions. Valid values include: `onActionGroupChange`: Actions run when the alert status changes; `onActiveAlert`: Actions run when the alert becomes active and at each check interval while the rule conditions are met; `onThrottleInterval`: Actions run when the alert becomes active and at the interval specified in the throttle property while the rule conditions are met. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `notify_when` values.",
 			Type:         schema.TypeString,
 			Optional:     true,
 			ValidateFunc: validation.StringInSlice([]string{"onActionGroupChange", "onActiveAlert", "onThrottleInterval"}, false),
@@ -140,7 +142,7 @@ func ResourceAlertingRule() *schema.Resource {
 			},
 		},
 		"throttle": {
-			Description:  "Defines how often an alert generates repeated actions. This custom action interval must be specified in seconds, minutes, hours, or days. For example, 10m or 1h. This property is applicable only if `notify_when` is `onThrottleInterval`. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `throttle` values.",
+			Description:  "Required until v8.6.0. Deprecated in 8.13.0. Defines how often an alert generates repeated actions. This custom action interval must be specified in seconds, minutes, hours, or days. For example, 10m or 1h. This property is applicable only if `notify_when` is `onThrottleInterval`. NOTE: This is a rule level property; if you update the rule in Kibana, it is automatically changed to use action-specific `throttle` values.",
 			Type:         schema.TypeString,
 			Optional:     true,
 			ValidateFunc: utils.StringIsDuration,
@@ -215,10 +217,30 @@ func getAlertingRuleFromResourceData(d *schema.ResourceData, serverVersion *vers
 	if v, ok := d.GetOk("throttle"); ok {
 		t := v.(string)
 		rule.Throttle = &t
+	} else {
+		if serverVersion.LessThan(frequencyMinSupportedVersion) {
+			return models.AlertingRule{}, diag.Diagnostics{
+				diag.Diagnostic{
+					Severity: diag.Error,
+					Summary:  "throttle is required until v8.6",
+					Detail:   "throttle is required until v8.6",
+				},
+			}
+		}
 	}
 
 	if v, ok := d.GetOk("notify_when"); ok {
 		rule.NotifyWhen = utils.Pointer(v.(string))
+	} else {
+		if serverVersion.LessThan(frequencyMinSupportedVersion) {
+			return models.AlertingRule{}, diag.Diagnostics{
+				diag.Diagnostic{
+					Severity: diag.Error,
+					Summary:  "notify_when is required until v8.6",
+					Detail:   "notify_when is required until v8.6",
+				},
+			}
+		}
 	}
 
 	if v, ok := d.GetOk("alert_delay"); ok {
@@ -230,7 +252,6 @@ func getAlertingRuleFromResourceData(d *schema.ResourceData, serverVersion *vers
 					Detail:   "alert_delay is only supported for Elasticsearch v8.13 or higher",
 				},
 			}
-
 		}
 
 		rule.AlertDelay = utils.Pointer(float32(v.(float64)))