[client] Restart engine when peer IP address changes

[lixmal]

Describe your changes

When management reallocates peer IPs (e.g. after a network range change), the client now restarts the engine instead of just logging the change. The firewall, route manager, and other components cache the old address, so a restart is needed for the new IP to take effect.

Uses the same ErrResetConnection + clientCancel() pattern as the network monitor and interface monitor restarts.

Issue ticket number and link

Stack

Checklist

• Is it a bug fix
• Is a typo/documentation fix
• Is a feature enhancement
• It is a refactor
• Created tests that fail without the change (if possible)

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Documentation

Select exactly one:

• I added/updated documentation for this change
• Documentation is not needed for this change (explain why)

Not needed: no user-facing API or configuration change.

Summary by CodeRabbit

• Bug Fixes
  • Improved handling of network interface address changes: the client now performs a clean restart to apply new IP configurations, ensuring updates take effect reliably.
  • Enhanced restart behavior and logging for clearer diagnostics and more robust connection recovery.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: f3881af1-ae78-47bd-b0b7-774eb0895668

📥 Commits

Reviewing files that changed from the base of the PR and between f9d596b and 527b904.

📒 Files selected for processing (1)

• client/internal/engine.go

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📝 Walkthrough

Walkthrough

Detects when the WireGuard interface IP differs from the new config and triggers a client restart: logs the restart, wraps ErrResetConnection into the context state, cancels the client, and returns ErrResetConnection. Remaining function behavior unchanged. (≤50 words)

Changes

Cohort / File(s)	Summary
IP Change Detection & Client Restart client/internal/engine.go	Replaces a comment with active logic: on WireGuard interface IP mismatch, log restart, set context state to ErrResetConnection, cancel current client operations, and return ErrResetConnection. Minor log text update.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• pappz

Poem

🐰 I sniffed the network, found a new IP tune,
I thumped my paw and hummed to the moon.
A gentle restart, a hop, then the mend—
Connections reset, and all's well again. 🥕✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title '[client] Restart engine when peer IP address changes' is clear, concise, and directly describes the main change in the PR—implementing engine restart logic when peer IP addresses are reallocated.
Description check	✅ Passed	The description is comprehensive and well-structured. It explains the motivation (cached components), implementation approach (reusing ErrResetConnection pattern), and provides proper documentation justification. All major template sections are addressed.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch restart-on-ip-change

📝 Coding Plan

• Generate coding plan for human review comments

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@client/internal/engine.go`:
- Around line 993-997: The restart path currently nulls out the wrapped error
and returns nil, allowing updateNetworkMap to continue; change the branch so it
returns the non-nil wrapped error instead of nil: return the result of
CtxGetState(e.ctx).Wrap(ErrResetConnection) after calling e.clientCancel()
(i.e., do not assign to `_`), so the caller (updateNetworkMap) short-circuits
further processing when e.clientCancel() is invoked.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 828d9746-7245-4979-86f3-37193fdd5304

📥 Commits

Reviewing files that changed from the base of the PR and between 628eb56 and f9d596b.

📒 Files selected for processing (1)

• client/internal/engine.go

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud