fix migration with bridge interface be more stable

[nanli1]

no sleep after case running would make bridge clean and host get ip process be more stable

Signed-off-by: nanli [email protected]

Also need avocado-framework/avocado-vt#4309 to make case pass

Before fixed:

virtual_network.migrate.migrate_with_bridge_type_interface.start_with_interface.precopy_migration.ovs_bridge FATAL: command execution failed

After fixed:

~# avocado run --vt-type libvirt  --vt-machine-type q35 virtual_network.migrate.migrate_with_bridge_type_interface
RESULTS    : PASS 12 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0

Summary by CodeRabbit

• Bug Fixes
  • Improved host connection stability by adding a short stabilization delay after bridge cleanup during virtual network teardown.
  • Modified post-migration guest network setup to skip DHCP lease refresh during session initialization.
  • Fixed remote session reliability by tightening the expected shell prompt handling during remote login.

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[coderabbitai]

Walkthrough

This test file modification adds an import of the time module, removes the post-migration DHCP lease refresh command (dhclient) on the guest, introduces a 5-second delay in teardown to stabilize host connectivity after bridge cleanup, and changes two remote_login SSH prompt expectations from the regex r'[$#%]' to the literal #.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly addresses the main change: improving stability for migration with bridge interface by adding delays and adjusting SSH expectations.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing touches

• 📝 Generate docstrings

---

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In
`@libvirt/tests/src/virtual_network/migrate/migrate_with_bridge_type_interface.py`:
- Around line 211-213: The SSH prompt is hardcoded as '#' in the remote_session
creation (aexpect.remote.remote_login) which breaks for non-root users or custom
prompts; update the prompt argument to use a regex pattern such as r'[$#%]' (or
the same configurable prompt pattern used across other migration tests) so the
login matches common shell prompts and avoids hangs/timeouts.

🧹 Nitpick comments (1)

libvirt/tests/src/virtual_network/migrate/migrate_with_bridge_type_interface.py (1)

175-179: Make the teardown delay configurable or readiness-based.
A fixed 5s sleep can still be flaky (too short) or wasteful (too long). Consider a parameterized wait or polling for connectivity.

♻️ Proposed tweak (parameterize the wait)

-        # Add some waiting time to make host connection stable after clean bridge.
-        time.sleep(5)
+        # Add some waiting time to make host connection stable after clean bridge.
+        bridge_cleanup_wait = int(params.get("bridge_cleanup_wait", "5"))
+        time.sleep(bridge_cleanup_wait)

[coderabbitai]

⚠️ Potential issue | 🟠 Major

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# First, check if the file exists and examine the relevant lines
if [ -f "libvirt/tests/src/virtual_network/migrate/migrate_with_bridge_type_interface.py" ]; then
  echo "=== File found. Checking lines 205-220 for context ==="
  sed -n '205,220p' libvirt/tests/src/virtual_network/migrate/migrate_with_bridge_type_interface.py
else
  echo "File not found at expected path. Searching for it..."
  find . -name "migrate_with_bridge_type_interface.py" -type f 2>/dev/null
fi

Repository: autotest/tp-libvirt

Length of output: 653

---

🏁 Script executed:

#!/bin/bash
# Check existing prompt usage patterns across the repo
echo "=== Remote login prompt patterns ==="
rg "remote_login" -A 3 -B 1 --max-count 20

Repository: autotest/tp-libvirt

Length of output: 25885

---

🏁 Script executed:

#!/bin/bash
# Check for params.get usage patterns in test files
echo "=== Checking params.get patterns in test files ==="
rg "params\.get.*prompt" --type py -C 2

Repository: autotest/tp-libvirt

Length of output: 10806

---

Fix SSH prompt hardcoding to support non-root users and custom prompts.

The literal '#' prompt fails for non-root users and systems with custom shell prompts, causing login hangs/timeouts. This is inconsistent with other migration test files in the same codebase, which use configurable patterns like r'[$#%]'.

Fix: Use regex pattern matching (lines 211-213)

     remote_session = aexpect.remote.remote_login("ssh", server_ip, "22",
-                                                 server_user, server_pwd,
-                                                 '#')
+                                                 server_user, server_pwd,
+                                                 r'[$#%]')

Alternatively, for test parameterization:

+    remote_prompt = params.get("remote_prompt", r'[$#%]')
     remote_session = aexpect.remote.remote_login("ssh", server_ip, "22",
-                                                 server_user, server_pwd,
-                                                 '#')
+                                                 server_user, server_pwd,
+                                                 remote_prompt)

🤖 Prompt for AI Agents

In
`@libvirt/tests/src/virtual_network/migrate/migrate_with_bridge_type_interface.py`
around lines 211 - 213, The SSH prompt is hardcoded as '#' in the remote_session
creation (aexpect.remote.remote_login) which breaks for non-root users or custom
prompts; update the prompt argument to use a regex pattern such as r'[$#%]' (or
the same configurable prompt pattern used across other migration tests) so the
login matches common shell prompts and avoids hangs/timeouts.

[nanli1]

No need to update this pr, All fixes are in avocado-framework/avocado-vt#4309