ipld-eth-beacon-indexer/pkg/gracefulshutdown/gracefulshutdown.go
Abdul Rabbani d1bc6a816f
Capture the head block in the DB entirely. (#27)
* -- Intermediary Commit --

Just want to commit my code over the weekend, in case I spill coffee on my workstation.

* Create DB models ready for write.

* Handle SSE events

* Update ref for stack-orchestrator

* Use env in one place only.

* Boot Application on PR

* Update syntax

* Update syntax

* Correct command

* Use bash instead of sh

* Use until instead of while

* Make linter happy and check sse subscription err

* Handle Reorgs - Untested
2022-05-06 11:03:15 -04:00

73 lines
1.7 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
var (
TimeoutErr = func(timeout string) error {
return fmt.Errorf("The Timeout %s, has been elapsed, the application will forcefully exit", timeout)
}
)
// gracefulShutdown waits for termination syscalls and doing clean up operations after received it
func Shutdown(ctx context.Context, notifierCh chan os.Signal, timeout time.Duration, ops map[string]Operation) (<-chan struct{}, <-chan error) {
waitCh := make(chan struct{})
errCh := make(chan error)
go func() {
// add any other syscalls that you want to be notified with
signal.Notify(notifierCh, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
<-notifierCh
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(TimeoutErr(timeout.String()).Error())
errCh <- TimeoutErr(timeout.String())
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
}