CKS: Use Zone MTUs when network is created at the time of CKS cluster creation

[Pearl1594]

Description

This PR fixes: #12205
When a cluster is created without specifying a network, then an isolated network is created automatically with the default MTU. However, if there is an MTU set at zone level, then it would be ideal to use that instead.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)
• Build/CI
• Test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Bug Severity

• BLOCKER
• Critical
• Major
• Minor
• Trivial

Screenshots (if appropriate):

How Has This Been Tested?

How did you try to break this feature and the system with this change?

[codecov]

Codecov Report

❌ Patch coverage is 0% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 16.21%. Comparing base (4348386) to head (a3cba04).
⚠️ Report is 71 commits behind head on 4.20.

Files with missing lines	Patch %	Lines
...bernetes/cluster/KubernetesClusterManagerImpl.java	0.00%	4 Missing ⚠️
...ain/java/com/cloud/network/NetworkServiceImpl.java	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               4.20   #12228   +/-   ##
=========================================
  Coverage     16.21%   16.21%           
- Complexity    13353    13354    +1     
=========================================
  Files          5657     5657           
  Lines        498647   498654    +7     
  Branches      60533    60533           
=========================================
+ Hits          80863    80869    +6     
+ Misses       408771   408766    -5     
- Partials       9013     9019    +6     

Flag	Coverage Δ
uitests	4.00% <ø> (ø)
unittests	17.07% <0.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Pearl1594]

@blueorangutan package

[blueorangutan]

@Pearl1594 a [SL] Jenkins job has been kicked to build packages. It will be bundled with KVM, XenServer and VMware SystemVM templates. I'll keep you posted as I make progress.

[sonarqubecloud]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 40%)

See analysis details on SonarQube Cloud

[blueorangutan]

Packaging result [SF]: ✔️ el8 ✔️ el9 ✔️ el10 ✔️ debian ✔️ suse15. SL-JID 15979

[shwstppr]

code lgtm

[Damans227]

Created a PR test environment and tested against it. Set zone-level MTU to 1400 (vr.public.interface.max.mtu and vr.private.interface.max.mtu), then created a CKS cluster without specifying a network. The auto-created network correctly inherited the zone MTU settings (publicmtu=1400, privatemtu=1400) instead of the default 1500. LGTM

[Damans227]

I tested it manually and posted my findings. LGTM.

[DaanHoogland]

@Pearl1594 is this ready (everybody but you seems to think so ;)

[Copilot]

Pull request overview

This PR fixes an issue where Kubernetes cluster default networks don't respect zone-level MTU restrictions. When a CKS cluster is created without specifying a network, an isolated network is automatically created. Previously, this network would always use the default 1500 MTU regardless of zone-level MTU settings. Now, the network creation respects the zone's configured MTU values.

Changes:

• Added a new overload of createGuestNetwork method that accepts zone MTU values as a parameter
• Updated Kubernetes cluster network creation to retrieve and pass zone MTU values when automatically creating networks

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
api/src/main/java/com/cloud/network/NetworkService.java	Added new method signature to the NetworkService interface that accepts MTU values for VR interfaces
server/src/main/java/com/cloud/network/NetworkServiceImpl.java	Implemented the new method overload that delegates to the network manager with MTU parameters
plugins/integrations/kubernetes-service/src/main/java/com/cloud/kubernetes/cluster/KubernetesClusterManagerImpl.java	Updated network creation logic to retrieve zone-level MTU values and pass them when creating the network
server/src/test/java/com/cloud/vpc/MockNetworkManagerImpl.java	Added mock implementation of the new interface method for test purposes

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The variable 'zoneId' is only assigned values of primitive type and is never 'null', but it is declared with the boxed type 'Long'.

Suggested change

	Long zoneId = zone.getId();
	long zoneId = zone.getId();