Add signal for exit

cmd/crproxy/main.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/daocloud/crproxy/cmd/crproxy/cluster"
 	csync "github.com/daocloud/crproxy/cmd/crproxy/sync"
+	"github.com/daocloud/crproxy/internal/signals"
 	"github.com/spf13/cobra"
 
 	_ "github.com/daocloud/crproxy/storage/driver/obs"
@@ -26,11 +27,11 @@ var (
 			return cmd.Usage()
 		},
 	}
-	pflag = cmd.Flags()
 )
 
 func main() {
-	err := cmd.Execute()
+	ctx := signals.SetupSignalContext()
+	err := cmd.ExecuteContext(ctx)
 	if err != nil {
 		slog.Error("execute failed", "error", err)
 		os.Exit(1)

internal/signals/signals.go

@@ -0,0 +1,32 @@
+package signals
+
+import (
+	"context"
+	"os"
+	"os/signal"
+)
+
+var (
+	onlyOneSignalHandler = make(chan struct{})
+	shutdownHandler      chan os.Signal
+)
+
+// SetupSignalContext is same as SetupSignalHandler, but a context.Context is returned.
+// Only one of SetupSignalContext and SetupSignalHandler should be called, and only can
+// be called once.
+func SetupSignalContext() context.Context {
+	close(onlyOneSignalHandler) // panics when called twice
+
+	shutdownHandler = make(chan os.Signal, 2)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	signal.Notify(shutdownHandler, shutdownSignals...)
+	go func() {
+		<-shutdownHandler
+		cancel()
+		<-shutdownHandler
+		os.Exit(1) // second signal. Exit directly.
+	}()
+
+	return ctx
+}

internal/signals/signals_other.go

@@ -0,0 +1,10 @@
+//go:build !windows
+
+package signals
+
+import (
+	"os"
+	"syscall"
+)
+
+var shutdownSignals = []os.Signal{os.Interrupt, syscall.SIGTERM}

internal/signals/signals_windows.go

@@ -0,0 +1,9 @@
+//go:build windows
+
+package signals
+
+import (
+	"os"
+)
+
+var shutdownSignals = []os.Signal{os.Interrupt}