VR: fix dns list in redundant VPC VRs

[weizhouapache]

Description

This PR fixes: #12107 #11879

Step to reproduce the issue

• create VPC with redundant offering
• create vpc tier and vm
• check /etc/dnsmasq.d/cloud.conf

expected: VPC tier gateway as the first option in the line for DNS

dhcp-option=tag:interface-eth2-0,6, VPC tier gateway, DNS1, DNS2

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

Feature/Enhancement Scale

• Major
• Minor

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

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 17.59%. Comparing base (b5fd39f) to head (11a14ae).

Additional details and impacted files

@@             Coverage Diff              @@
##               4.22   #12161      +/-   ##
============================================
- Coverage     17.59%   17.59%   -0.01%     
+ Complexity    15601    15599       -2     
============================================
  Files          5910     5910              
  Lines        529780   529780              
  Branches      64729    64729              
============================================
- Hits          93226    93204      -22     
- Misses       426060   426083      +23     
+ Partials      10494    10493       -1     

Flag	Coverage Δ
uitests	3.60% <ø> (ø)
unittests	18.66% <ø> (-0.01%)	⬇️

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[weizhouapache]

@blueorangutan package

[blueorangutan]

@weizhouapache 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.

[blueorangutan]

Packaging result [SF]: ✔️ el8 ✔️ el9 ✔️ el10 ✔️ debian ✔️ suse15. SL-JID 15857

[weizhouapache]

@blueorangutan test

[blueorangutan]

@weizhouapache a [SL] Trillian-Jenkins test job (ol8 mgmt + kvm-ol8) has been kicked to run smoke tests

[Jayd603]

This patch worked for me.

[weizhouapache]

@blueorangutan test

[blueorangutan]

@weizhouapache a [SL] Trillian-Jenkins test job (ol8 mgmt + kvm-ol8) has been kicked to run smoke tests

[blueorangutan]

Packaging result [SF]: ✔️ el8 ✔️ el9 ✔️ el10 ✔️ debian ✔️ suse15. SL-JID 15869

[blueorangutan]

[SF] Trillian test result (tid-14892)
Environment: kvm-ol8 (x2), zone: Advanced Networking with Mgmt server ol8
Total time taken: 51401 seconds
Marvin logs: https://github.com/blueorangutan/acs-prs/releases/download/trillian/pr12161-t14892-kvm-ol8.zip
Smoke tests completed. 149 look OK, 0 have errors, 0 did not run
Only failed and skipped tests results shown below:

Test	Result	Time (s)	Test File

[DaanHoogland]

@weizhouapache , does this need testing for non-vpc non-redundant routers? cc @nvazquez @Pearl1594 .

[weizhouapache]

@weizhouapache , does this need testing for non-vpc non-redundant routers? cc @nvazquez @Pearl1594 .

yes @DaanHoogland

the change was introduced in #9102, but may be related to the Netris plugin too (#10458)
@nvazquez @Pearl1594

[Jayd603]

I just hit the below error trying to deploy an instance with this fix in place. 169.254.39.227 is the current BACKUP VPC router. Will try to debug further.

2025-12-03 16:52:27,797 DEBUG [c.c.a.t.Request] (AgentManager-Handler-9:[]) (logid:) Seq 28-8558246666887546921: Processing:  { Ans: , MgmtId: 90520744930075, via: 28, Ver: v1, Flags: 10, [{"com.cloud.agent.api.routing.GroupAnswer":{"results":["null - success: Creating file in VR, with ip: 169.254.39.227, file: monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d","null - failed: java.io.IOException: Stream closed

Upon second deployment attempt, it tried the PRIMARY router and also failed. hmm.

[weizhouapache]

monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

@Jayd603 can you run the following commands inthe VPC VR ?

cd /var/cache/cloud
cp processed/monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d.gz .
gzip -dk monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d.gz
update_config.py monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

[Jayd603]

monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

@Jayd603 can you run the following commands inthe VPC VR ?

cd /var/cache/cloud
cp processed/monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d.gz .
gzip -dk monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d.gz
update_config.py monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

I noticed I used tabs in the python file, durr, fixed that now other errors:

(r-95-VM) Resource [Host:28] is unreachable: Host 28: Unable to start instance due to Unable to start VM:fcdb10f4-1bde-4cc0-a04f-afd20a2392f2 due to error in finalizeStart, not retrying

I fixed the .py files and attempted router reboot - totally fails now.

also - that file you pasted does not exist.

I'm re-deploying fresh routers without your patch - after that, other than modifying the .py files on each router, what else do I need to do to test this?

[Jayd603]

monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

@Jayd603 can you run the following commands inthe VPC VR ?

After deploying fresh routers, i was able to apply your patch and reboot them both, then was able to deploy with password functionality. Not sure what happened but seems ok now . I'm doing more testing and will report back if I notice anything.

[weizhouapache]

monitor_service.json.23cd5b3b-c47e-457e-bc28-9bb079d34f9d

@Jayd603 can you run the following commands inthe VPC VR ?

After deploying fresh routers, i was able to apply your patch and reboot them both, then was able to deploy with password functionality. Not sure what happened but seems ok now . I'm doing more testing and will report back if I notice anything.

good, good to know it.

[weizhouapache]

@blueorangutan package

[weizhouapache]

verified by
#11879 (comment)