Signal Context (signalcontext) is a Go library for creating Go context's that
cancel on signals. This is very useful for client-side applications that want to cancel operations on user interrupts (e.g. CTRL+C).
-
Small - A very tiny API and less than 50 lines of code.
-
Independent - No external dependencies besides the Go standard library, meaning it won't bloat your project.
-
Flexible - Use native Go contexts and extend/wrap as needed.
Here is an example for gracefully stopping an HTTP server when the user presses CTRL+C in their terminal:
package main
import (
"context"
"log"
"net/http"
"syscall"
"time"
"github.com/sethvargo/go-signalcontext"
)
func main() {
ctx, cancel := signalcontext.OnInterrupt()
defer cancel()
s := &http.Server{
Addr: ":8080",
}
go func() {
if err := s.ListenAndServe(); err != nil {
log.Fatal(err)
}
}()
// Wait for CTRL+C
<-ctx.Done()
// Stop the server
shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
if err := s.Shutdown(shutdownCtx); err != nil {
log.Fatal(err)
}
}You can also use custom signals:
ctx, cancel := signalcontext.On(syscall.SIGUSR1)
defer cancel()And also wrap an existing context:
ctx1, cancel1 := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel1()
ctx2, cancel2 := signalcontext.Wrap(ctx1, syscall.SIGUSR1)
defer cancel2()