/
main.go
126 lines (106 loc) · 2.8 KB
/
main.go
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package main
import (
"flag"
"fmt"
"log"
"net/http"
"os"
"os/signal"
"strconv"
"strings"
"syscall"
"time"
"github.com/gokrazy/gokrazy"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
_ "net/http/pprof"
)
var (
listen = flag.String("listen",
":8014",
"[host]:port to listen on (for prometheus HTTP exports)")
lastSuccessPath = flag.String("last_success_path",
"/perm/dr-last-success.txt",
"path to a file in which to load/store the last success timestamp")
opportunisticBackupHosts = flag.String("opportunistic_backup_hosts",
"verkaufg9",
"Comma-separated list of hosts to back up when they become reachable")
)
var lastSuccess = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "last_success",
Help: "Timestamp of the last success",
})
func init() {
prometheus.MustRegister(lastSuccess)
}
func loadLastSuccess() error {
b, err := os.ReadFile(*lastSuccessPath)
if err != nil {
return err
}
i, err := strconv.ParseInt(strings.TrimSpace(string(b)), 0, 64)
if err != nil {
return err
}
lastSuccess.Set(float64(i))
return nil
}
func main() {
gokrazy.WaitForClock()
if err := loadLastSuccess(); err != nil {
log.Printf("could not load last success timestamp from disk: %v", err)
}
http.Handle("/metrics", promhttp.Handler())
go http.ListenAndServe(*listen, nil)
runCh := make(chan struct{})
go func() {
// Run forever, trigger a run at 10:00 each Monday through Friday.
for {
now := time.Now()
runToday := now.Hour() < 10 &&
now.Weekday() != time.Saturday &&
now.Weekday() != time.Sunday
today := now.Day()
log.Printf("now = %v, runToday = %v", now, runToday)
for {
if time.Now().Day() != today {
// Day changed, re-evaluate whether to run today.
break
}
nextHour := time.Now().Truncate(time.Hour).Add(1 * time.Hour)
log.Printf("today = %d, runToday = %v, next hour: %v", today, runToday, nextHour)
time.Sleep(time.Until(nextHour))
if time.Now().Hour() >= 10 && runToday {
runToday = false
runCh <- struct{}{}
}
}
}
}()
go func() {
c := make(chan os.Signal, 1)
signal.Notify(c, syscall.SIGUSR1)
for range c {
log.Printf("received SIGUSR1, starting run")
runCh <- struct{}{}
}
}()
// Subscribe to MQTT, listen for suspendnas command
go func() {
if err := runMQTT(); err != nil {
log.Printf("MQTT: %v", err)
}
}()
go runOpportunisticBackups(*opportunisticBackupHosts)
for range runCh {
log.Println("Running dornröschen")
if err := run(); err != nil {
log.Printf("failed: %v", err)
}
unix := time.Now().Unix()
lastSuccess.Set(float64(unix))
if err := os.WriteFile(*lastSuccessPath, []byte(fmt.Sprintf("%d", unix)), 0600); err != nil {
log.Printf("could not persist last success timestamp to disk: %v", err)
}
}
}