// ntp is a minimal NTP client for gokrazy. package main import ( "log" "math/rand" "os" "syscall" "time" "github.com/beevik/ntp" ) func set(rtc *os.File) error { r, err := ntp.Query("0.gokrazy.pool.ntp.org") if err != nil { return err } tv := syscall.NsecToTimeval(r.Time.UnixNano()) if err := syscall.Settimeofday(&tv); err != nil { return err } if rtc == nil { return nil } return setRTC(rtc, r.Time.UTC()) } func main() { log.SetFlags(log.LstdFlags | log.Lshortfile) var rtc *os.File var err error if os.Getenv("NTP_PRIVILEGES_DROPPED") == "1" { if os.Getenv("NTP_RTC") == "1" { rtc = os.NewFile(3, "/dev/rtc0") } } else { rtc, err = os.Open("/dev/rtc0") if err != nil && !os.IsNotExist(err) { log.Fatal(err) } } mustDropPrivileges(rtc) for { if err := set(rtc); err != nil { log.Fatalf("setting time failed: %v", err) } time.Sleep(1*time.Hour + time.Duration(rand.Int63n(250))*time.Millisecond) } }