Add support for forecast options in AlertPolicy (#7926) (#14616)

Signed-off-by: Modular Magician <[email protected]>
Co-authored-by: James Edouard <[email protected]>

Author: modular-magician

.changelog/7926.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+monitoring: added `forecast_options` field to `google_monitoring_alert_policy` resource
+```

google/resource_monitoring_alert_policy.go

@@ -672,6 +672,31 @@ resource labels, and metric labels. This
 field may not exceed 2048 Unicode characters
 in length.`,
 									},
+									"forecast_options": {
+										Type:     schema.TypeList,
+										Optional: true,
+										Description: `When this field is present, the 'MetricThreshold'
+condition forecasts whether the time series is
+predicted to violate the threshold within the
+'forecastHorizon'. When this field is not set, the
+'MetricThreshold' tests the current value of the
+timeseries against the threshold.`,
+										MaxItems: 1,
+										Elem: &schema.Resource{
+											Schema: map[string]*schema.Schema{
+												"forecast_horizon": {
+													Type:     schema.TypeString,
+													Required: true,
+													Description: `The length of time into the future to forecast
+whether a timeseries will violate the threshold.
+If the predicted value is found to violate the
+threshold, and the violation is observed in all
+forecasts made for the Configured 'duration',
+then the timeseries is considered to be failing.`,
+												},
+											},
+										},
+									},
 									"threshold_value": {
 										Type:     schema.TypeFloat,
 										Optional: true,
@@ -1518,6 +1543,8 @@ func flattenMonitoringAlertPolicyConditionsConditionThreshold(v interface{}, d *
 		flattenMonitoringAlertPolicyConditionsConditionThresholdDenominatorAggregations(original["denominatorAggregations"], d, config)
 	transformed["duration"] =
 		flattenMonitoringAlertPolicyConditionsConditionThresholdDuration(original["duration"], d, config)
+	transformed["forecast_options"] =
+		flattenMonitoringAlertPolicyConditionsConditionThresholdForecastOptions(original["forecastOptions"], d, config)
 	transformed["comparison"] =
 		flattenMonitoringAlertPolicyConditionsConditionThresholdComparison(original["comparison"], d, config)
 	transformed["trigger"] =
@@ -1579,6 +1606,23 @@ func flattenMonitoringAlertPolicyConditionsConditionThresholdDuration(v interfac
 	return v
 }
 
+func flattenMonitoringAlertPolicyConditionsConditionThresholdForecastOptions(v interface{}, d *schema.ResourceData, config *transport_tpg.Config) interface{} {
+	if v == nil {
+		return nil
+	}
+	original := v.(map[string]interface{})
+	if len(original) == 0 {
+		return nil
+	}
+	transformed := make(map[string]interface{})
+	transformed["forecast_horizon"] =
+		flattenMonitoringAlertPolicyConditionsConditionThresholdForecastOptionsForecastHorizon(original["forecastHorizon"], d, config)
+	return []interface{}{transformed}
+}
+func flattenMonitoringAlertPolicyConditionsConditionThresholdForecastOptionsForecastHorizon(v interface{}, d *schema.ResourceData, config *transport_tpg.Config) interface{} {
+	return v
+}
+
 func flattenMonitoringAlertPolicyConditionsConditionThresholdComparison(v interface{}, d *schema.ResourceData, config *transport_tpg.Config) interface{} {
 	return v
 }
@@ -2124,6 +2168,13 @@ func expandMonitoringAlertPolicyConditionsConditionThreshold(v interface{}, d tp
 		transformed["duration"] = transformedDuration
 	}
 
+	transformedForecastOptions, err := expandMonitoringAlertPolicyConditionsConditionThresholdForecastOptions(original["forecast_options"], d, config)
+	if err != nil {
+		return nil, err
+	} else if val := reflect.ValueOf(transformedForecastOptions); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+		transformed["forecastOptions"] = transformedForecastOptions
+	}
+
 	transformedComparison, err := expandMonitoringAlertPolicyConditionsConditionThresholdComparison(original["comparison"], d, config)
 	if err != nil {
 		return nil, err
@@ -2233,6 +2284,29 @@ func expandMonitoringAlertPolicyConditionsConditionThresholdDuration(v interface
 	return v, nil
 }
 
+func expandMonitoringAlertPolicyConditionsConditionThresholdForecastOptions(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
+	l := v.([]interface{})
+	if len(l) == 0 || l[0] == nil {
+		return nil, nil
+	}
+	raw := l[0]
+	original := raw.(map[string]interface{})
+	transformed := make(map[string]interface{})
+
+	transformedForecastHorizon, err := expandMonitoringAlertPolicyConditionsConditionThresholdForecastOptionsForecastHorizon(original["forecast_horizon"], d, config)
+	if err != nil {
+		return nil, err
+	} else if val := reflect.ValueOf(transformedForecastHorizon); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+		transformed["forecastHorizon"] = transformedForecastHorizon
+	}
+
+	return transformed, nil
+}
+
+func expandMonitoringAlertPolicyConditionsConditionThresholdForecastOptionsForecastHorizon(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
+	return v, nil
+}
+
 func expandMonitoringAlertPolicyConditionsConditionThresholdComparison(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
 	return v, nil
 }

google/resource_monitoring_alert_policy_test.go

@@ -15,11 +15,12 @@ import (
 
 func TestAccMonitoringAlertPolicy(t *testing.T) {
 	testCases := map[string]func(t *testing.T){
-		"basic":  testAccMonitoringAlertPolicy_basic,
-		"full":   testAccMonitoringAlertPolicy_full,
-		"update": testAccMonitoringAlertPolicy_update,
-		"mql":    testAccMonitoringAlertPolicy_mql,
-		"log":    testAccMonitoringAlertPolicy_log,
+		"basic":    testAccMonitoringAlertPolicy_basic,
+		"full":     testAccMonitoringAlertPolicy_full,
+		"update":   testAccMonitoringAlertPolicy_update,
+		"mql":      testAccMonitoringAlertPolicy_mql,
+		"log":      testAccMonitoringAlertPolicy_log,
+		"forecast": testAccMonitoringAlertPolicy_forecast,
 	}
 
 	for name, tc := range testCases {
@@ -181,6 +182,29 @@ func testAccCheckAlertPolicyDestroyProducer(t *testing.T) func(s *terraform.Stat
 	}
 }
 
+func testAccMonitoringAlertPolicy_forecast(t *testing.T) {
+
+	alertName := fmt.Sprintf("tf-test-%s", RandString(t, 10))
+	conditionName := fmt.Sprintf("tf-test-%s", RandString(t, 10))
+	filter := `metric.type=\"compute.googleapis.com/instance/disk/write_bytes_count\" AND resource.type=\"gce_instance\"`
+
+	VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckAlertPolicyDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccMonitoringAlertPolicy_forecastCfg(alertName, conditionName, "ALIGN_RATE", filter),
+			},
+			{
+				ResourceName:      "google_monitoring_alert_policy.forecast",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
 func testAccMonitoringAlertPolicy_basicCfg(alertName, conditionName, aligner, filter string) string {
 	return fmt.Sprintf(`
 resource "google_monitoring_alert_policy" "basic" {
@@ -335,3 +359,32 @@ resource "google_monitoring_alert_policy" "log" {
 }
 `, alertName, conditionName)
 }
+
+func testAccMonitoringAlertPolicy_forecastCfg(alertName, conditionName, aligner, filter string) string {
+	return fmt.Sprintf(`
+resource "google_monitoring_alert_policy" "forecast" {
+  display_name = "%s"
+  enabled      = true
+  combiner     = "OR"
+
+  conditions {
+    display_name = "%s"
+
+    condition_threshold {
+      aggregations {
+        alignment_period   = "60s"
+        per_series_aligner = "%s"
+      }
+
+      duration        = "60s"
+      forecast_options {
+        forecast_horizon = "3600s"
+      }
+      comparison      = "COMPARISON_GT"
+      filter          = "%s"
+      threshold_value = "0.5"
+    }
+  }
+}
+`, alertName, conditionName, aligner, filter)
+}

website/docs/r/monitoring_alert_policy.html.markdown

@@ -83,6 +83,34 @@ resource "google_monitoring_alert_policy" "alert_policy" {
   }
 }
 ```
+## Example Usage - Monitoring Alert Policy Forecast Options
+
+
+```hcl
+resource "google_monitoring_alert_policy" "alert_policy" {
+  display_name = "My Alert Policy"
+  combiner     = "OR"
+  conditions {
+    display_name = "test condition"
+    condition_threshold {
+      filter     = "metric.type=\"compute.googleapis.com/instance/disk/write_bytes_count\" AND resource.type=\"gce_instance\""
+      duration   = "60s"
+      forecast_options {
+        forecast_horizon = "3600s"
+      }
+      comparison = "COMPARISON_GT"
+      aggregations {
+        alignment_period   = "60s"
+        per_series_aligner = "ALIGN_RATE"
+      }
+    }
+  }
+
+  user_labels = {
+    foo = "bar"
+  }
+}
+```
 
 ## Argument Reference
 
@@ -427,6 +455,16 @@ The following arguments are supported:
   that unhealthy states are detected and
   alerted on quickly.
 
+* `forecast_options` -
+  (Optional)
+  When this field is present, the `MetricThreshold`
+  condition forecasts whether the time series is
+  predicted to violate the threshold within the
+  `forecastHorizon`. When this field is not set, the
+  `MetricThreshold` tests the current value of the
+  timeseries against the threshold.
+  Structure is [documented below](#nested_forecast_options).
+
 * `comparison` -
   (Required)
   The comparison to apply between the time
@@ -580,6 +618,17 @@ The following arguments are supported:
   returned.
   Possible values are: `REDUCE_NONE`, `REDUCE_MEAN`, `REDUCE_MIN`, `REDUCE_MAX`, `REDUCE_SUM`, `REDUCE_STDDEV`, `REDUCE_COUNT`, `REDUCE_COUNT_TRUE`, `REDUCE_COUNT_FALSE`, `REDUCE_FRACTION_TRUE`, `REDUCE_PERCENTILE_99`, `REDUCE_PERCENTILE_95`, `REDUCE_PERCENTILE_50`, `REDUCE_PERCENTILE_05`.
 
+<a name="nested_forecast_options"></a>The `forecast_options` block supports:
+
+* `forecast_horizon` -
+  (Required)
+  The length of time into the future to forecast
+  whether a timeseries will violate the threshold.
+  If the predicted value is found to violate the
+  threshold, and the violation is observed in all
+  forecasts made for the Configured `duration`,
+  then the timeseries is considered to be failing.
+
 <a name="nested_trigger"></a>The `trigger` block supports:
 
 * `percent` -