/* Copyright 2023 The Dapr Authors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package signals import ( "context" "errors" "os" "os/signal" "github.com/dapr/kit/logger" ) var ( log = logger.NewLogger("dapr.signals") // Inspired by // https://github.com/kubernetes-sigs/controller-runtime/blob/8499b67e316a03b260c73f92d0380de8cd2e97a1/pkg/manager/signals/signal.go#L25 onlyOneSignalHandler = make(chan struct{}) ) // Context returns a context which will be canceled when either the SIGINT // (windows and non windows) or SIGTERM (non windows) signal is caught. If // either signal is caught a second time, the program is terminated immediately // with exit code 1. func Context() context.Context { // panics when called twice close(onlyOneSignalHandler) ctx, cancel := context.WithCancelCause(context.Background()) sigCh := make(chan os.Signal, 1) signal.Notify(sigCh, shutdownSignals...) go func() { sig := <-sigCh log.Infof(`Received signal '%s'; beginning shutdown`, sig) //nolint:err113 cancel(errors.New("cancelling context, received signal " + sig.String())) sig = <-sigCh log.Fatalf( `Received signal '%s' during shutdown; exiting immediately`, sig, ) }() return ctx }