ipld-eth-beacon-indexer/pkg/gracefulshutdown/gracefulshutdown.go

68 lines
1.6 KiB
Go

package gracefulshutdown
import (
"context"
"fmt"
"os"
"os/signal"
"sync"
"syscall"
"time"
log "github.com/sirupsen/logrus"
"github.com/vulcanize/ipld-ethcl-indexer/pkg/loghelper"
)
// operation is a clean up function on shutting down
type Operation func(ctx context.Context) error
// gracefulShutdown waits for termination syscalls and doing clean up operations after received it
func Shutdown(ctx context.Context, timeout time.Duration, ops map[string]Operation) (<-chan struct{}, <-chan error) {
waitCh := make(chan struct{})
errCh := make(chan error)
go func() {
s := make(chan os.Signal, 1)
// add any other syscalls that you want to be notified with
signal.Notify(s, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
<-s
log.Info("Shutting Down your application")
// set timeout for the ops to be done to prevent system hang
timeoutFunc := time.AfterFunc(timeout, func() {
log.Warnf("timeout %d ms has been elapsed, force exit", timeout.Milliseconds())
errCh <- fmt.Errorf("Application shutdown took too long.")
return
})
defer timeoutFunc.Stop()
var wg sync.WaitGroup
// Do the operations asynchronously to save time
for key, op := range ops {
wg.Add(1)
innerOp := op
innerKey := key
go func() {
defer wg.Done()
log.Infof("cleaning up: %s", innerKey)
if err := innerOp(ctx); err != nil {
loghelper.LogError(err).Errorf("%s: clean up failed: %s", innerKey, err.Error())
return
}
log.Infof("%s was shutdown gracefully", innerKey)
}()
}
wg.Wait()
close(waitCh)
}()
return waitCh, errCh
}