From 11bcb24e40348dabf83e3641988ee1d6c37dc596 Mon Sep 17 00:00:00 2001
From: Thomas Ferrandiz <thomas.ferrandiz@suse.com>
Date: Fri, 21 Apr 2023 12:41:48 +0000
Subject: [PATCH] ensure that klog verbosity is set to the same level as logrus
 by repeatedly settting it every second during k3s startup

Signed-off-by: Thomas Ferrandiz <thomas.ferrandiz@suse.com>
---
 go.mod                        |  2 +-
 pkg/daemons/executor/embed.go | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/go.mod b/go.mod
index d35c2b067d3e..52533b606e98 100644
--- a/go.mod
+++ b/go.mod
@@ -135,6 +135,7 @@ require (
 	k8s.io/component-helpers v0.25.9
 	k8s.io/cri-api v0.26.0-alpha.3
 	k8s.io/klog v1.0.0
+	k8s.io/klog/v2 v2.80.1
 	k8s.io/kubectl v0.25.9
 	k8s.io/kubernetes v1.25.9
 	k8s.io/utils v0.0.0-20221107191617-1a15be271d1d
@@ -374,7 +375,6 @@ require (
 	k8s.io/controller-manager v0.25.9 // indirect
 	k8s.io/csi-translation-lib v0.0.0 // indirect
 	k8s.io/gengo v0.0.0-20211129171323-c02415ce4185 // indirect
-	k8s.io/klog/v2 v2.80.1 // indirect
 	k8s.io/kube-aggregator v0.25.4 // indirect
 	k8s.io/kube-controller-manager v0.0.0 // indirect
 	k8s.io/kube-openapi v0.0.0-20220803162953-67bda5d908f1 // indirect
diff --git a/pkg/daemons/executor/embed.go b/pkg/daemons/executor/embed.go
index c09dd8277bae..2db37591e788 100644
--- a/pkg/daemons/executor/embed.go
+++ b/pkg/daemons/executor/embed.go
@@ -5,9 +5,12 @@ package executor
 
 import (
 	"context"
+	"flag"
 	"net/http"
 	"runtime"
 	"runtime/debug"
+	"strconv"
+	"time"
 
 	"github.com/k3s-io/k3s/pkg/cli/cmds"
 	daemonconfig "github.com/k3s-io/k3s/pkg/daemons/config"
@@ -31,6 +34,7 @@ import (
 	cloudcontrollerconfig "k8s.io/cloud-provider/app/config"
 	ccmopt "k8s.io/cloud-provider/options"
 	cliflag "k8s.io/component-base/cli/flag"
+	"k8s.io/klog/v2"
 	"k8s.io/kubernetes/cmd/kube-apiserver/app"
 	cmapp "k8s.io/kubernetes/cmd/kube-controller-manager/app"
 	proxy "k8s.io/kubernetes/cmd/kube-proxy/app"
@@ -47,6 +51,26 @@ func init() {
 
 func (e *Embedded) Bootstrap(ctx context.Context, nodeConfig *daemonconfig.Node, cfg cmds.Agent) error {
 	e.nodeConfig = nodeConfig
+
+	go func() {
+		// Ensure that the log verbosity remains set to the configured level by resetting it at 1-second intervals
+		// for the first 2 minutes that K3s is starting up. This is necessary because each of the Kubernetes
+		// components will initialize klog and reset the verbosity flag when they are starting.
+		logCtx, cancel := context.WithTimeout(ctx, time.Second*120)
+		defer cancel()
+
+		klog.InitFlags(nil)
+		for {
+			flag.Set("v", strconv.Itoa(cmds.LogConfig.VLevel))
+
+			select {
+			case <-time.After(time.Second):
+			case <-logCtx.Done():
+				return
+			}
+		}
+	}()
+
 	return nil
 }