mirror of
https://github.com/optim-enterprises-bv/kubernetes.git
synced 2025-11-03 19:58:17 +00:00
d5067208e4
`golang.org/x/sys/unix`.`Sysinfo` only provide uptime in whole second, which leads to +-1s drifting in the boot time calculation. Reading from /proc/stat is a better option as there's a reliable boot time directly returned from linux kernel.
75 lines
2.1 KiB
Go
75 lines
2.1 KiB
Go
//go:build linux
|
|
// +build linux
|
|
|
|
/*
|
|
Copyright 2018 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package util
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"golang.org/x/sys/unix"
|
|
"k8s.io/klog/v2"
|
|
)
|
|
|
|
// GetBootTime returns the time at which the machine was started, truncated to the nearest second.
|
|
// It uses /proc/stat first, which is more accurate, and falls back to the less accurate
|
|
// unix.Sysinfo if /proc/stat failed.
|
|
func GetBootTime() (time.Time, error) {
|
|
bootTime, err := getBootTimeWithProcStat()
|
|
if err != nil {
|
|
klog.InfoS("Failed to get boot time from /proc/uptime. Will retry with unix.Sysinfo.", "error", err)
|
|
return getBootTimeWithSysinfo()
|
|
}
|
|
return bootTime, nil
|
|
}
|
|
|
|
func getBootTimeWithProcStat() (time.Time, error) {
|
|
raw, err := os.ReadFile("/proc/stat")
|
|
if err != nil {
|
|
return time.Time{}, fmt.Errorf("error getting boot time: %w", err)
|
|
}
|
|
rawFields := strings.Fields(string(raw))
|
|
for i, v := range rawFields {
|
|
if v == "btime" {
|
|
if len(rawFields) > i+1 {
|
|
sec, err := strconv.ParseInt(rawFields[i+1], 10, 64)
|
|
if err != nil {
|
|
return time.Time{}, fmt.Errorf("error parsing boot time %s: %w", rawFields[i+1], err)
|
|
}
|
|
return time.Unix(sec, 0), nil
|
|
}
|
|
break
|
|
}
|
|
}
|
|
|
|
return time.Time{}, fmt.Errorf("can not find btime from /proc/stat: %s", raw)
|
|
}
|
|
|
|
func getBootTimeWithSysinfo() (time.Time, error) {
|
|
currentTime := time.Now()
|
|
var info unix.Sysinfo_t
|
|
if err := unix.Sysinfo(&info); err != nil {
|
|
return time.Time{}, fmt.Errorf("error getting system uptime: %w", err)
|
|
}
|
|
return currentTime.Add(-time.Duration(info.Uptime) * time.Second).Truncate(time.Second), nil
|
|
}
|