Add end-to-end smoke driving the real CLI against the containerized fake

internal/cli/cli.go

@@ -53,6 +53,20 @@ func Run(args []string, stdout, stderr io.Writer) int {
 		fmt.Fprint(stderr, usage)
 		return 1
 	}
+	// Hoist a leading global --config PATH onto the subcommand (the
+	// subcommand flag sets already accept it anywhere).
+	var hoisted []string
+	for len(args) >= 2 && (args[0] == "--config" || args[0] == "-config") {
+		hoisted = append(hoisted, args[0], args[1])
+		args = args[2:]
+	}
+	if len(hoisted) > 0 {
+		if len(args) == 0 {
+			fmt.Fprint(stderr, usage)
+			return 1
+		}
+		args = append(args, hoisted...)
+	}
 	switch args[0] {
 	case "help", "-h", "--help":
 		fmt.Fprint(stdout, usage)