podman unshare keep exit code

In case the command inside the podman unshare env failed podman unshare
always exits with 125 and prints `Error: exit status 125`. This is a
bad user experience and makes it difficult to use in scripts which could
expect certain exit codes.
This commit makes sure podman unshare uses the same exit code as the
command and does not print the useless `exit status X` message.

Also to match podman run/exec it should return 126 for EPERM
and 127 for ENOENT.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/cmd/podman/system/unshare.go b/cmd/podman/system/unshare.go
index f930d8b62..50230609e 100644
--- a/cmd/podman/system/unshare.go
+++ b/cmd/podman/system/unshare.go
@@ -2,6 +2,7 @@ package system
 
 import (
 	"os"
+	"os/exec"
 
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/podman/v3/cmd/podman/registry"
@@ -50,5 +51,23 @@ func unshare(cmd *cobra.Command, args []string) error {
 		args = []string{shell}
 	}
 
-	return registry.ContainerEngine().Unshare(registry.Context(), args, unshareOptions)
+	err := registry.ContainerEngine().Unshare(registry.Context(), args, unshareOptions)
+	if err != nil {
+		if exitError, ok := err.(*exec.ExitError); ok {
+			// the user command inside the unshare env has failed
+			// we set the exit code, do not return the error to the user
+			// otherwise "exit status X" will be printed
+			registry.SetExitCode(exitError.ExitCode())
+			return nil
+		}
+		// cmd.Run() can return fs.ErrNotExist, fs.ErrPermission or exec.ErrNotFound
+		// follow podman run/exec standard with the exit codes
+		if errors.Is(err, os.ErrNotExist) || errors.Is(err, exec.ErrNotFound) {
+			registry.SetExitCode(127)
+		} else if errors.Is(err, os.ErrPermission) {
+			registry.SetExitCode(126)
+		}
+		return err
+	}
+	return nil
 }