nixos/test: Add copy_from_host and copy_from_host_via_shell to python

test driver

nixos/lib/test-driver/test-driver.py

@@ -1,13 +1,17 @@
 #! /somewhere/python3
 from contextlib import contextmanager, _GeneratorContextManager
+from queue import Queue, Empty
+from typing import Tuple, Any, Callable, Dict, Iterator, Optional, List
 from xml.sax.saxutils import XMLGenerator
 import _thread
 import atexit
+import base64
 import os
+import pathlib
 import ptpython.repl
 import pty
-from queue import Queue, Empty
 import re
+import shlex
 import shutil
 import socket
 import subprocess
@@ -15,9 +19,6 @@ import sys
 import tempfile
 import time
 import unicodedata
-from typing import Tuple, Any, Callable, Dict, Iterator, Optional, List
-import shlex
-import pathlib
 
 CHAR_TO_KEY = {
     "A": "shift-a",
@@ -566,6 +567,41 @@ class Machine:
             if ret.returncode != 0:
                 raise Exception("Cannot convert screenshot")
 
+    def copy_from_host_via_shell(self, source: str, target: str) -> None:
+        """Copy a file from the host into the guest by piping it over the
+        shell into the destination file. Works without host-guest shared folder.
+        Prefer copy_from_host for whenever possible.
+        """
+        with open(source, "rb") as fh:
+            content_b64 = base64.b64encode(fh.read()).decode()
+            self.succeed(
+                f"mkdir -p $(dirname {target})",
+                f"echo -n {content_b64} | base64 -d > {target}",
+            )
+
+    def copy_from_host(self, source: str, target: str) -> None:
+        """Copy a file from the host into the guest via the `shared_dir` shared
+        among all the VMs (using a temporary directory).
+        """
+        host_src = pathlib.Path(source)
+        vm_target = pathlib.Path(target)
+        with tempfile.TemporaryDirectory(dir=self.shared_dir) as shared_td:
+            shared_temp = pathlib.Path(shared_td)
+            host_intermediate = shared_temp / host_src.name
+            vm_shared_temp = pathlib.Path("/tmp/shared") / shared_temp.name
+            vm_intermediate = vm_shared_temp / host_src.name
+
+            self.succeed(make_command(["mkdir", "-p", vm_shared_temp]))
+            if host_src.is_dir():
+                shutil.copytree(host_src, host_intermediate)
+            else:
+                shutil.copy(host_src, host_intermediate)
+            self.succeed("sync")
+            self.succeed(make_command(["mkdir", "-p", vm_target.parent]))
+            self.succeed(make_command(["cp", "-r", vm_intermediate, vm_target]))
+        # Make sure the cleanup is synced into VM
+        self.succeed("sync")
+
     def copy_from_vm(self, source: str, target_dir: str = "") -> None:
         """Copy a file from the VM (specified by an in-VM source path) to a path
         relative to `$out`. The file is copied via the `shared_dir` shared among