feat(alerting): Add RESULT_CONDITIONS in custom alert to have more information on an alert while using custom alerting module

Author: aalmenar

README.md

@@ -1555,7 +1555,8 @@ Furthermore, you may use the following placeholders in the body (`alerting.custo
 - `[ENDPOINT_GROUP]` (resolved from `endpoints[].group`)
 - `[ENDPOINT_URL]` (resolved from `endpoints[].url`)
 - `[RESULT_ERRORS]` (resolved from the health evaluation of a given health check)
-
+- `[RESULT_CONDITIONS]` (condition results from the health evaluation of a given health check)
+-
 If you have an alert using the `custom` provider with `send-on-resolved` set to `true`, you can use the
 `[ALERT_TRIGGERED_OR_RESOLVED]` placeholder to differentiate the notifications.
 The aforementioned placeholder will be replaced by `TRIGGERED` or `RESOLVED` accordingly, though it can be modified

alerting/provider/custom/custom.go

@@ -111,6 +111,26 @@ func (provider *AlertProvider) buildHTTPRequest(cfg *Config, ep *endpoint.Endpoi
 	resultErrors := strings.ReplaceAll(strings.Join(result.Errors, ","), "\"", "\\\"")
 	body = strings.ReplaceAll(body, "[RESULT_ERRORS]", resultErrors)
 	url = strings.ReplaceAll(url, "[RESULT_ERRORS]", resultErrors)
+
+	var formattedConditionResults string
+	if len(result.ConditionResults) > 0 {
+		for index, conditionResult := range result.ConditionResults {
+			var prefix string
+			if conditionResult.Success {
+				prefix = "✅"
+			} else {
+				prefix = "❌"
+			}
+			formattedConditionResults += fmt.Sprintf("%s - `%s`", prefix, conditionResult.Condition)
+			if index < len(result.ConditionResults)-1 {
+				formattedConditionResults += ", "
+			}
+		}
+	}
+
+	body = strings.ReplaceAll(body, "[RESULT_CONDITIONS]", formattedConditionResults)
+	url = strings.ReplaceAll(url, "[RESULT_CONDITIONS]", formattedConditionResults)
+
 	if resolved {
 		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))
 		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))