apply nncp to configure DNS, then edit nncp to update nameserver, but /etc/resolv.conf is not updated.

OCP version: 4.16.0-0.nightly-2024-03-13-061822
knmstate operator version: kubernetes-nmstate-operator.4.16.0-202403111814

always

1. install knmstate operator
2. apply below nncp to configure dns on one of the node
---
apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: dns-staticip-4
spec:
  nodeSelector:
    kubernetes.io/hostname: qiowang-031510-k4cjs-worker-0-rw4nt
  desiredState:
    dns-resolver:
      config:
        search:
        - example.org
        server:
        - 192.168.221.146
        - 8.8.9.9
    interfaces:
    - name: dummy44
      type: dummy
      state: up
      ipv4:
        address:
        - ip: 192.0.2.251
          prefix-length: 24
        dhcp: false
        enabled: true
        auto-dns: false
% oc apply -f dns-staticip-noroute.yaml 
nodenetworkconfigurationpolicy.nmstate.io/dns-staticip-4 created
% oc get nncp
NAME             STATUS      REASON
dns-staticip-4   Available   SuccessfullyConfigured
% oc get nnce
NAME                                                 STATUS      STATUS AGE   REASON
qiowang-031510-k4cjs-worker-0-rw4nt.dns-staticip-4   Available   5s           SuccessfullyConfigured


3. check dns on the node, dns configured correctly
sh-5.1# cat /etc/resolv.conf 
# Generated by KNI resolv prepender NM dispatcher script
search qiowang-031510.qe.devcluster.openshift.com example.org
nameserver 192.168.221.146
nameserver 192.168.221.146
nameserver 8.8.9.9
# nameserver 192.168.221.1
sh-5.1# 
sh-5.1# cat /var/run/NetworkManager/resolv.conf 
# Generated by NetworkManager
search example.org
nameserver 192.168.221.146
nameserver 8.8.9.9
nameserver 192.168.221.1
sh-5.1# 
sh-5.1# nmcli | grep 'DNS configuration' -A 10
DNS configuration:
	servers: 192.168.221.146 8.8.9.9
	domains: example.org
	interface: dummy44
... ...


4. edit nncp, update nameserver, save the modification
---
spec:
  desiredState:
    dns-resolver:
      config:
        search:
        - example.org
        server:
        - 192.168.221.146
        - 8.8.8.8       <---- update from 8.8.9.9 to 8.8.8.8
    interfaces:
    - ipv4:
        address:
        - ip: 192.0.2.251
          prefix-length: 24
        auto-dns: false
        dhcp: false
        enabled: true
      name: dummy44
      state: up
      type: dummy
  nodeSelector:
    kubernetes.io/hostname: qiowang-031510-k4cjs-worker-0-rw4nt
% oc edit nncp dns-staticip-4
nodenetworkconfigurationpolicy.nmstate.io/dns-staticip-4 edited
% oc get nncp
NAME             STATUS      REASON
dns-staticip-4   Available   SuccessfullyConfigured
% oc get nnce
NAME                                                 STATUS      STATUS AGE   REASON
qiowang-031510-k4cjs-worker-0-rw4nt.dns-staticip-4   Available   8s           SuccessfullyConfigured


5. check dns on the node again

the dns nameserver in file /etc/resolv.conf is not updated after nncp updated, file /var/run/NetworkManager/resolv.conf updated correctly: 

sh-5.1# cat /etc/resolv.conf 
# Generated by KNI resolv prepender NM dispatcher script
search qiowang-031510.qe.devcluster.openshift.com example.org
nameserver 192.168.221.146
nameserver 192.168.221.146
nameserver 8.8.9.9        <---- it is not updated
# nameserver 192.168.221.1
sh-5.1# 
sh-5.1# cat /var/run/NetworkManager/resolv.conf 
# Generated by NetworkManager
search example.org
nameserver 192.168.221.146
nameserver 8.8.8.8        <---- updated correctly
nameserver 192.168.221.1
sh-5.1# 
sh-5.1# nmcli | grep 'DNS configuration' -A 10
DNS configuration:
	servers: 192.168.221.146 8.8.8.8
	domains: example.org
	interface: dummy44
... ...

the dns nameserver in file /etc/resolv.conf can be updated accordingly