azure aks not able to pull images from acr

it was a working set up and no manual changes were made.

when we are trying to deploy application on aks; it fails to pull an image from the acr.

as per kubectl describe po output:

Failed to pull image "xyz.azurecr.io/xyz:-beta-68": [rpc error: code = Unknown desc = Error response from daemon: Get https://xyz.azurecr.io/v2/: dial tcp: lookup rxyz.azurecr.io on [::1]:53: read udp [::1]:46256->[::1]:53: read: connection refused, rpc error: code = Unknown desc = Error response from daemon: Get https://xyz.azurecr.io/v2/: dial tcp: lookup xyz.azurecr.io on [::1]:53: read udp [::1]:46112->[::1]:53: read: connection refused, rpc error: code = Unknown desc = Error response from daemon: Get https://xyz.azurecr.io/v2/: dial tcp: lookup xyz.azurecr.io on [::1]:53: read udp [::1]:36677->[::1]:53: read: connection refused]

while troubleshooting i realised, few nodes has the dns entry in /etc/resolv.conf where image pull is working fine without issue and few node doesn’t have the dns entry in /etc/resolv.conf where the image pull fails.

and if i manually add dns entry to /etc/resolv.conf on the nodes that doesn’t have the entry; the changes are reverted to the initial state withing few minutes.

is there a procedure to edit /etc/resolv.conf or fix image pull issues.?