cmd/run: Add --arch flag for container architecture selection

Add the --arch / -a flag to the run command, allowing users to run
commands inside cross-architecture containers by specifying the target
architecture (e.g., toolbox run --arch arm64 uname -m). Can be used
with flags --distro and --release, just as for container creation.

The flag value is resolved through resolveArchitectureID()
(added in [1]) and passed to resolveContainerAndImageNames()
(updated for cross-arch in [1])  so that it resolves to the
architecture-suffixed container name.

[1] containers#1786

containers#1789

Signed-off-by: Dalibor Kricka <dalidalk@seznam.cz>

Author: DaliborKr

src/cmd/run.go

@@ -53,6 +53,7 @@ type entryPointError struct {
 
 var (
 	runFlags struct {
+		arch        string
 		container   string
 		distro      string
 		preserveFDs uint
@@ -74,6 +75,12 @@ func init() {
 	flags := runCmd.Flags()
 	flags.SetInterspersed(false)
 
+	flags.StringVarP(&runFlags.arch,
+		"arch",
+		"a",
+		"",
+		"Run command inside a Toolbx container for a different architecture than the host")
+
 	flags.StringVarP(&runFlags.container,
 		"container",
 		"c",
@@ -142,12 +149,17 @@ func run(cmd *cobra.Command, args []string) error {
 
 	command := args
 
+	archID, err := resolveArchitectureID(runFlags.arch, "")
+	if err != nil {
+		return err
+	}
+
 	container, image, release, err := resolveContainerAndImageNames(runFlags.container,
 		"--container",
 		runFlags.distro,
 		"",
 		runFlags.release,
-		architecture.HostArchID)
+		archID)
 
 	if err != nil {
 		return err