fix comments

Signed-off-by: Yijie Qin <qinyijie@amazon.com>

notify/notify.go

@@ -54,6 +54,14 @@ const MinTimeout = 10 * time.Second
 // defaultStatusCodeCategory is the default status code category for numTotalFailedNotifications metric
 const defaultStatusCodeCategory = "5xx"
 
+const (
+	failure4xxCategoryCode = "4xx"
+	failure5xxCategoryCode = "5xx"
+)
+
+// possibleFailureStatusCategory is a list of possible failure status code category
+var possibleFailureStatusCategory = []string{failure4xxCategoryCode, failure5xxCategoryCode}
+
 // Notifier notifies about alerts under constraints of the given context. It
 // returns an error if unsuccessful and a flag whether the error is
 // recoverable. This information is useful for a retry logic.
@@ -300,7 +308,7 @@ func NewMetrics(r prometheus.Registerer) *Metrics {
 		m.numNotificationRequestsFailedTotal.WithLabelValues(integration)
 		m.notificationLatencySeconds.WithLabelValues(integration)
 
-		for _, code := range PossibleFailureStatusCategory {
+		for _, code := range possibleFailureStatusCategory {
 			m.numTotalFailedNotifications.WithLabelValues(integration, code)
 		}
 	}
@@ -672,10 +680,7 @@ func (r RetryStage) Exec(ctx context.Context, l log.Logger, alerts ...*types.Ale
 	statusCodeCategory := defaultStatusCodeCategory
 	if err != nil {
 		if e, ok := errors.Cause(err).(*ErrorWithStatusCode); ok {
-			result, interErr := getFailureStatusCodeCategory(e.StatusCode)
-			if interErr == nil {
-				statusCodeCategory = result
-			}
+			statusCodeCategory = getFailureStatusCodeCategory(e.StatusCode)
 		}
 		r.metrics.numTotalFailedNotifications.WithLabelValues(r.integration.Name(), statusCodeCategory).Inc()
 	}
@@ -890,3 +895,17 @@ func inTimeIntervals(now time.Time, intervals map[string][]timeinterval.TimeInte
 	}
 	return false, nil
 }
+
+// getFailureStatusCodeCategory return the status code category for failure request
+// the status starts with 4 will return 4xx and starts with 5 will return 5xx
+// other than 4xx and 5xx input status will return an 5xx.
+func getFailureStatusCodeCategory(statusCode int) string {
+	if statusCode/100 == 4 {
+		return failure4xxCategoryCode
+	}
+	if statusCode/100 == 5 {
+		return failure5xxCategoryCode
+	}
+
+	return defaultStatusCodeCategory
+}

notify/util.go

@@ -30,18 +30,9 @@ import (
 	"github.com/prometheus/alertmanager/types"
 )
 
-const (
-	failure4xxCategoryCode     = "4xx"
-	failure5xxCategoryCode     = "5xx"
-	failureUnknownCategoryCode = "unknown"
-)
-
 // UserAgentHeader is the default User-Agent for notification requests
 var UserAgentHeader = fmt.Sprintf("Alertmanager/%s", version.Version)
 
-// PossibleFailureStatusCategory is a list of possible failure status code category
-var PossibleFailureStatusCategory = []string{failure4xxCategoryCode, failure5xxCategoryCode, failureUnknownCategoryCode}
-
 // RedactURL removes the URL part from an error of *url.Error type.
 func RedactURL(err error) error {
 	e, ok := err.(*url.Error)
@@ -176,20 +167,6 @@ func readAll(r io.Reader) string {
 	return string(bs)
 }
 
-// getFailureStatusCodeCategory return the status code category for failure request
-// the status starts with 4 will return 4xx and starts with 5 will return 5xx
-// other than 4xx and 5xx input status will return an error.
-func getFailureStatusCodeCategory(statusCode int) (string, error) {
-	if statusCode/100 == 4 {
-		return failure4xxCategoryCode, nil
-	}
-	if statusCode/100 == 5 {
-		return failure5xxCategoryCode, nil
-	}
-
-	return failureUnknownCategoryCode, fmt.Errorf("unexpected status code %v", statusCode)
-}
-
 // Retrier knows when to retry an HTTP request to a receiver. 2xx status codes
 // are successful, anything else is a failure and only 5xx status codes should
 // be retried.