Process group (#8)

* No need to delete namespace in case of kill

We kill the child process, so the Wait will continue and clean
everything properly

* Create the child process in a new process group

This solves the 'stdin not being printed' problem \o/

Author: PouuleT

main.go

@@ -263,7 +263,7 @@ func main() {
 		return
 	}
 
-	log.Debug("Cleaning ...")
+	log.Debug("Exiting properly ...")
 }
 
 func execCmd(cmdString string) error {
@@ -287,14 +287,13 @@ func execCmd(cmdString string) error {
 		return err
 	}
 
-	// TODO: There seems to be a problem if a Signal is catched, stdin is not
-	// printed anymore on the terminal. A `reset` is needed
-	stdin := os.Stdin
-
 	// Pass stdin / stdout / stderr as proc attributes
 	procAttr := os.ProcAttr{
-		Files: []*os.File{stdin, os.Stdout, os.Stderr},
+		Files: []*os.File{os.Stdin, os.Stdout, os.Stderr},
 		Dir:   pwd,
+		Sys: &syscall.SysProcAttr{
+			Setpgid: true,
+		},
 	}
 
 	log.Debugf("Going to run `%s ( %s ) %s`", cmdElmnts[0], bin, strings.Join(cmdElmnts[1:], " "))
@@ -314,7 +313,6 @@ func execCmd(cmdString string) error {
 		if err != nil {
 			log.Warn("Failed to change the namespace: ", err)
 		}
-		stdin.Close()
 
 		// If there is a process, need to kill it
 		if proc != nil {
@@ -328,20 +326,6 @@ func execCmd(cmdString string) error {
 		} else {
 			log.Debugf("No process to kill")
 		}
-
-		// If there is a namespace, need to delete it
-		if namespace != nil {
-			log.Debugf("Deleting the namespace")
-			err := deleteNS(namespace)
-			if err != nil {
-				log.Warnf("error while deleting namespace", err)
-			} else {
-				log.Debugf("Namespace deleted")
-			}
-		} else {
-			log.Debugf("No namespace to delete")
-		}
-		os.Exit(1)
 	}()
 
 	// Start the process
@@ -359,7 +343,6 @@ func execCmd(cmdString string) error {
 	}
 
 	log.Debugf("Result : %s", state)
-	stdin.Close()
 
 	return nil
 }
@@ -415,6 +398,8 @@ func getOriginalNS() (*netns.NsHandle, error) {
 
 // deleteNS will delete the given namespace
 func deleteNS(ns *netns.NsHandle) error {
+	log.Debugf("Deleting namespace")
+
 	// Close the nsHandler
 	err := ns.Close()
 	if err != nil {