From edaf55ba6284ebc7ff954efb87cbbdc142afce89 Mon Sep 17 00:00:00 2001
From: Jarrod Johnson <jjohnson2@lenovo.com>
Date: Fri, 2 Oct 2026 10:44:26 -0400
Subject: [PATCH] Try to scope DNS to interfaces if possible

netplan and NetworkManager both scope dns to interface.

In certain cases, it can really mean it, so try to match the nameservers to the appropriate interface,
falling back to adding to every interface with a gateway.
---
 .../common/profile/scripts/confignet          | 48 ++++++++++++++-----
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/confluent_osdeploy/common/profile/scripts/confignet b/confluent_osdeploy/common/profile/scripts/confignet
index 3f8daecc..2dd7d152 100644
--- a/confluent_osdeploy/common/profile/scripts/confignet
+++ b/confluent_osdeploy/common/profile/scripts/confignet
@@ -8,7 +8,9 @@ import sys
 import time
 import shlex
 import subprocess
+ipaddress = None
 try:
+    import ipaddress
     import yaml
 except ImportError:
     pass
@@ -255,7 +257,10 @@ class NetplanManager(object):
                     else:
                         needcfgwrite = True
                         cfgroutes.append({'via': gwaddr, 'to': 'default'})
-            dnsips = self.deploycfg.get('nameservers', [])
+            if ipaddress:
+                dnsips = stgs.get('ipv4_nameservers', []) + stgs.get('ipv6_nameservers', [])
+            else:
+                dnsips = self.deploycfg.get('nameservers', [])
             dnsdomain = self.deploycfg.get('dnsdomain', '')
             if dnsips:
                 currdnsips = self.getcfgarrpath([devname, 'nameservers', 'addresses'])
@@ -526,16 +531,13 @@ class NetworkManager(object):
             cmdargs['ipv6.gateway'] = stgs['ipv6_gateway']
         if stgs.get('mtu', None):
             cmdargs['802-3-ethernet.mtu'] = stgs['mtu']
-        dnsips = self.deploycfg.get('nameservers', [])
-        if not dnsips:
-            dnsips = []
-        dns4 = []
-        dns6 = []
-        for dnsip in dnsips:
-            if '.' in dnsip:
-                dns4.append(dnsip)
-            elif ':' in dnsip:
-                dns6.append(dnsip)
+        if ipaddress:
+            dns4 = stgs.get('ipv4_nameservers', [])
+            dns6 = stgs.get('ipv6_nameservers', [])
+        else:
+            dnsips = self.deploycfg.get('nameservers', [])
+            dns4 = [ip for ip in dnsips if '.' in ip]
+            dns6 = [ip for ip in dnsips if ':' in ip]
         if dns4:
             cmdargs['ipv4.dns'] = ','.join(dns4)
         if dns6:
@@ -697,6 +699,30 @@ if __name__ == '__main__':
     elif os.path.exists('/usr/sbin/wicked'):
         nm = WickedManager()
     retrynics = []
+    if ipaddress:
+        dnsbynetname = {}
+        dnsips = set(dc.get('nameservers', []))
+        for dnsip in list(dnsips):
+            dnsipaddr = ipaddress.ip_address(dnsip)
+            ipver = f'ipv{dnsipaddr.version}'
+            for netn in netname_to_interfaces:
+                currstgs = netname_to_interfaces[netn]['settings']
+                if currstgs.get(f'{ipver}_method') == 'static':
+                    currip = currstgs.get(f'{ipver}_address')
+                    if currip:
+                        currip = ipaddress.ip_interface(currip)
+                        if dnsipaddr in currip.network:
+                            currstgs.setdefault(f'{ipver}_nameservers', []).append(dnsip)
+                            dnsips.discard(dnsip)
+        for dnsip in dnsips:
+            dnsipaddr = ipaddress.ip_address(dnsip)
+            ipver = f'ipv{dnsipaddr.version}'                    
+            for netn in netname_to_interfaces:
+                currstgs = netname_to_interfaces[netn]['settings']
+                if currstgs.get(f'{ipver}_method') == 'static':
+                    gateway = currstgs.get(f'{ipver}_gateway')
+                    if gateway:
+                        currstgs.setdefault(f'{ipver}_nameservers', []).append(dnsip)
     for netn in netname_to_interfaces:
         redo = nm.apply_configuration(netname_to_interfaces[netn])
         if redo == 1: