// TrapSignals tells the process to trap incoming process signals.
func TrapSignals(ctx apitypes.Context) {
context.RegisterCustomKey(signalContextKey, context.CustomLoggerKey)
sigc := make(chan os.Signal, 1)
signal.Notify(sigc)
go func() {
for s := range sigc {
ctx := ctx.WithValue(signalContextKey, s.String())
if ok, graceful := IsExitSignal(s); ok && !graceful {
ctx.Error("received signal; aborting")
os.Exit(1)
}
func() {
sigHandlersRWL.RLock()
defer sigHandlersRWL.RUnlock()
// execute the signal handlers in reverse order. the first
// one registered should be executed last as it was registered
// the earliest
for i := len(sigHandlers) - 1; i >= 0; i-- {
sigHandlers[i](ctx, s)
}
}()
if ok, graceful := IsExitSignal(s); ok && graceful {
ctx.Error("received signal; shutting down")
os.Exit(0)
}
}
}()
}
func init() {
context.RegisterCustomKey(transactionHeaderKey, context.CustomHeaderKey)
context.RegisterCustomKey(instanceIDHeaderKey, context.CustomHeaderKey)
context.RegisterCustomKey(localDevicesHeaderKey, context.CustomHeaderKey)
}