Fix shutdown hang: add timeout to discovery entry deletion

cmd/dmsg/commands/root.go

@@ -3,6 +3,9 @@ package commands
 
 import (
 	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/skycoin/skywire/pkg/skywire-utilities/pkg/buildinfo"
 	"github.com/skycoin/skywire/pkg/skywire-utilities/pkg/calvin"
@@ -24,8 +27,9 @@ import (
 )
 
 var (
-	bv  bool
-	dbi bool
+	bv       bool
+	dbi      bool
+	withKill bool
 )
 
 func init() {
@@ -63,6 +67,8 @@ func init() {
 	di.RootCmd.Use = "ip"
 
 	modifySubcommands(RootCmd)
+	RootCmd.PersistentFlags().BoolVar(&withKill, "with-kill", false, "force exit after 3 interrupt signals")
+	RootCmd.PersistentFlags().MarkHidden("with-kill") //nolint:errcheck,gosec
 	if fmt.Sprintf("%v", buildinfo.DebugBuildInfo()) != "" {
 		RootCmd.Flags().BoolVarP(&dbi, "info", "d", false, "print runtime/debug.BuildInfo")
 	}
@@ -98,6 +104,21 @@ var RootCmd = &cobra.Command{
 		}
 		return ret
 	}(),
+	PersistentPreRun: func(_ *cobra.Command, _ []string) {
+		if withKill {
+			c := make(chan os.Signal, 1)
+			signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+			go func() {
+				sigCount := 0
+				for range c {
+					sigCount++
+					if sigCount >= 3 {
+						os.Exit(1)
+					}
+				}
+			}()
+		}
+	},
 	SilenceErrors:         true,
 	SilenceUsage:          true,
 	DisableSuggestions:    true,

pkg/dmsg/client.go

@@ -377,7 +377,12 @@ func (ce *Client) Close() error {
 		ce.sessionsMx.Unlock()
 		ce.porter.CloseAll(ce.log)
 		ce.wg.Wait()
-		err = ce.EntityCommon.delEntry(context.Background())
+		// Use a short timeout for discovery cleanup — if the discovery
+		// server is accessed over dmsg (which we just closed), this
+		// request would hang forever with context.Background().
+		delCtx, delCancel := context.WithTimeout(context.Background(), 5*time.Second)
+		err = ce.EntityCommon.delEntry(delCtx)
+		delCancel()
 	})
 	return err
 }