Tests for snapshot network renames

Author: andrewla

tests/framework/microvm.py

@@ -26,7 +26,7 @@
 from enum import Enum
 from functools import lru_cache
 from pathlib import Path
-from typing import Optional
+from typing import Optional, Dict
 
 from tenacity import retry, stop_after_attempt, wait_fixed
 
@@ -919,6 +919,7 @@ def restore_from_snapshot(
         snapshot: Snapshot,
         resume: bool = False,
         uffd_path: Path = None,
+        rename_interfaces: Dict[str, str] = None,
     ):
         """Restore a snapshot"""
         jailed_snapshot = snapshot.copy_to_chroot(Path(self.chroot()))
@@ -941,11 +942,16 @@ def restore_from_snapshot(
         if uffd_path is not None:
             mem_backend = {"backend_type": "Uffd", "backend_path": str(uffd_path)}
 
+        iface_overrides = []
+        if rename_interfaces:
+            iface_overrides = [{"iface_id": k, "host_dev_name": v} for k,v in rename_interfaces.items()]
+
         self.api.snapshot_load.put(
             mem_backend=mem_backend,
             snapshot_path=str(jailed_vmstate),
             enable_diff_snapshots=snapshot.is_diff,
             resume_vm=resume,
+            network_overrides=iface_overrides,
         )
         return jailed_snapshot
 
@@ -986,13 +992,13 @@ def thread_backtraces(self):
                 )
         return "\n".join(backtraces)
 
-    def wait_for_up(self, timeout=10):
+    def wait_for_up(self, timeout=10, iface=0):
         """Wait for guest running inside the microVM to come up and respond.
 
         :param timeout: seconds to wait.
         """
         try:
-            rc, stdout, stderr = self.ssh.run("true", timeout)
+            rc, stdout, stderr = self.ssh_iface(iface).run("true", timeout)
         except subprocess.TimeoutExpired:
             print(
                 f"Remote command did not respond within {timeout}s\n\n"

tests/integration_tests/functional/test_snapshot_basic.py

@@ -8,11 +8,13 @@
 import re
 import shutil
 import time
+import dataclasses
 from pathlib import Path
 
 import pytest
 
 import host_tools.drive as drive_tools
+import host_tools.network as net_tools
 from framework.microvm import SnapshotType
 from framework.utils import check_filesystem, check_output
 from framework.utils_vsock import (
@@ -577,3 +579,30 @@ def test_vmgenid(guest_kernel_linux_6_1, rootfs, microvm_factory, snapshot_type)
 
         # Update the base for next iteration
         base_snapshot = snapshot
+
+def test_snapshot_rename_interface(uvm_nano, microvm_factory):
+    """
+    Test that we can restore a snapshot and point its interface to a
+    different host interface.
+    """
+    base_iface = net_tools.NetIfaceConfig.with_id(0)
+
+    vm = uvm_nano
+    iface1 = dataclasses.replace(base_iface, tap_name="tap1")
+    vm.add_net_iface(iface=iface1)
+    # Create an interface but don't attach it to the device
+    vm.start()
+    vm.wait_for_up()
+
+    snapshot = vm.snapshot_full()
+
+    restored_vm = microvm_factory.build()
+    restored_vm.spawn()
+    iface2 = dataclasses.replace(base_iface, tap_name="tap2")
+    snapshot.net_ifaces.clear()
+    snapshot.net_ifaces.append(iface2)
+    restored_vm.restore_from_snapshot(snapshot, rename_interfaces=
+                                      {base_iface.dev_name: "tap2"})
+    restored_vm.resume()
+    restored_vm.wait_for_up()
+