Revert to use a constructor again

Without this, we have no validation of the data in command/signal
reboot.

This was not a problem in the first refactor, as the constructor
was a dummy one, without validation.

However, as we refactoed, we now have code in the root method
that is validation for the reboot command. This can now be
encompassed in the constructor.

Signed-off-by: Jean-Philippe Evrard <open-source@a.spamming.party>

cmd/kured/main.go

@@ -35,7 +35,6 @@ import (
 	"github.com/kubereboot/kured/pkg/reboot"
 	"github.com/kubereboot/kured/pkg/taints"
 	"github.com/kubereboot/kured/pkg/timewindow"
-	"github.com/kubereboot/kured/pkg/util"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
@@ -722,19 +721,14 @@ func root(cmd *cobra.Command, args []string) {
 	}
 	log.Infof("Reboot schedule: %v", window)
 
-	restartCommand, err := shlex.Split(rebootCommand)
-	if err != nil {
-		log.Fatalf("Error parsing provided reboot command: %v", err)
-	}
-
 	var rebooter reboot.Rebooter
 	switch {
 	case rebootMethod == "command":
-		log.Infof("Reboot command: %s", restartCommand)
-		rebooter = reboot.CommandRebooter{RebootCommand: util.PrivilegedHostCommand(1, restartCommand)}
+		log.Infof("Reboot command: %s", rebootCommand)
+		rebooter = reboot.NewCommandRebooter(rebootCommand)
 	case rebootMethod == "signal":
 		log.Infof("Reboot signal: %v", rebootSignal)
-		rebooter = reboot.SignalRebooter{Signal: rebootSignal}
+		rebooter = reboot.NewSignalRebooter(rebootSignal)
 	default:
 		log.Fatalf("Invalid reboot-method configured: %s", rebootMethod)
 	}

pkg/reboot/command.go

@@ -1,11 +1,12 @@
 package reboot
 
 import (
+	"github.com/google/shlex"
 	"github.com/kubereboot/kured/pkg/util"
 	log "github.com/sirupsen/logrus"
 )
 
-// CommandRebooter holds context-information for a command reboot.
+// CommandRebooter holds context-information for a reboot with command
 type CommandRebooter struct {
 	RebootCommand []string
 }
@@ -17,3 +18,15 @@ func (c CommandRebooter) Reboot() {
 		log.Fatalf("Error invoking reboot command: %v", err)
 	}
 }
+
+// NewCommandRebooter is the constructor to create a CommandRebooter from a string not
+// yet shell lexed. You can skip this constructor if you parse the data correctly first
+// when instantiating a CommandRebooter instance.
+func NewCommandRebooter(rebootCommand string) *CommandRebooter {
+	cmd, err := shlex.Split(rebootCommand)
+	if err != nil {
+		log.Fatalf("Error parsing provided reboot command: %v", err)
+	}
+
+	return &CommandRebooter{RebootCommand: util.PrivilegedHostCommand(1, cmd)}
+}

pkg/reboot/signal.go

@@ -28,3 +28,9 @@ func (c SignalRebooter) Reboot() {
 		log.Fatalf("Signal of SIGRTMIN+5 failed: %v", err)
 	}
 }
+
+// NewSignalRebooter is the constructor which sets the signal number.
+// The constructor does not yet validate any input. It should be done in a later commit.
+func NewSignalRebooter(sig int) *SignalRebooter {
+	return &SignalRebooter{Signal: sig}
+}