buildkit/util/appcontext/appcontext.go

47 lines
848 B
Go

package appcontext
import (
"context"
"os"
"os/signal"
"sync"
"github.com/sirupsen/logrus"
)
var appContextCache context.Context
var appContextOnce sync.Once
// Context returns a static context that reacts to termination signals of the
// running process. Useful in CLI tools.
func Context() context.Context {
appContextOnce.Do(func() {
signals := make(chan os.Signal, 2048)
signal.Notify(signals, terminationSignals...)
const exitLimit = 3
retries := 0
ctx := context.Background()
for _, f := range inits {
ctx = f(ctx)
}
ctx, cancel := context.WithCancel(ctx)
appContextCache = ctx
go func() {
for {
<-signals
cancel()
retries++
if retries >= exitLimit {
logrus.Errorf("got %d SIGTERM/SIGINTs, forcing shutdown", retries)
os.Exit(1)
}
}
}()
})
return appContextCache
}