From 7906316741eb7deed2d0d7fb90ba50505ba37de3 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 3 Mar 2021 10:30:39 +0200
Subject: [PATCH] lib/promscrape/discovery/kubernetes: properly check for nil
pointer inside interface
See https://mangatmodi.medium.com/go-check-nil-interface-the-right-way-d142776edef1
This fixes a panic when the ScrapeWork is filtered out in swcFunc.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1108
---
lib/promscrape/discovery/kubernetes/api.go | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/promscrape/discovery/kubernetes/api.go b/lib/promscrape/discovery/kubernetes/api.go
index da858bd274..1d319a671a 100644
--- a/lib/promscrape/discovery/kubernetes/api.go
+++ b/lib/promscrape/discovery/kubernetes/api.go
@@ -12,6 +12,7 @@ import (
"net/http"
"net/url"
"os"
+ "reflect"
"strconv"
"strings"
"sync"
@@ -380,7 +381,8 @@ func getScrapeWorkObjectsForLabels(swcFunc ScrapeWorkConstructorFunc, labelss []
swos := make([]interface{}, 0, len(labelss))
for _, labels := range labelss {
swo := swcFunc(labels)
- if swo != nil {
+ // The reflect check is needed because of https://mangatmodi.medium.com/go-check-nil-interface-the-right-way-d142776edef1
+ if swo != nil && !reflect.ValueOf(swo).IsNil() {
swos = append(swos, swo)
}
}