Merge pull request #54094 from juanvallejo/jvallejo/exit-plugin-cmd-w…

…-correct-exit-code

Automatic merge from submit-queue (batch tested with PRs 54107, 54184, 54377, 54094, 54111). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

exit with correct exit code on plugin failure

**Release note**:
```release-note
NONE
```

Correctly exits after a plugin command execution failure with the correct exit code.
Related downstream bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1501756

**Before**
```
$ kubectl plugin will-fail-plugin
ls: cannot access 'does-not-exist': No such file or directory
error: exit status 2

$ echo $?
1
```

**After**
```
$ kubectl plugin will-fail-plugin
ls: cannot access 'does-not-exist': No such file or directory
error: exit status 2

$ echo $?
2
```

cc @fabianofranz

pkg/kubectl/cmd/plugin.go

@@ -19,6 +19,9 @@ package cmd
 import (
 	"fmt"
 	"io"
+	"os"
+	"os/exec"
+	"syscall"
 
 	"github.com/golang/glog"
 	"github.com/spf13/cobra"
@@ -109,6 +112,15 @@ func NewCmdForPlugin(f cmdutil.Factory, plugin *plugins.Plugin, runner plugins.P
 			}
 
 			if err := runner.Run(plugin, runningContext); err != nil {
+				if exiterr, ok := err.(*exec.ExitError); ok {
+					// check for (and exit with) the correct exit code
+					// from a failed plugin command execution
+					if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
+						fmt.Fprintf(errout, "error: %v\n", err)
+						os.Exit(status.ExitStatus())
+					}
+				}
+
 				cmdutil.CheckErr(err)
 			}
 		},