Ensure default search domain is preserved when converting Azure VM network interface to be managed by NetworkManager

azure-networkmanager-preserve-search-domain.yaml

- hosts: all
  tasks:
    - name: create custom fact directory
      file:
        path: /etc/ansible/facts.d
        state: directory
    
    - name: insert azure fact file
      copy:
        src: azure_resolv.fact
        dest: /etc/ansible/facts.d/azure_resolv.fact
        mode: 0755
      register: azure_resolv_fact_file
    
    - name: rediscover facts
      setup: ~
      when: azure_resolv_fact_file.changed
    
    - name: configure default search domain
      lineinfile:
        dest: "/etc/sysconfig/network-scripts/ifcfg-{{ ansible_default_ipv4['interface'] }}"
        regexp: '^DOMAIN='
        line: 'DOMAIN={{ ansible_local.azure_resolv.search_domain }}'
        state: present
        create: yes
      register: interface_domain_configuration
    
    - name: reconfigure interface
      shell: "ifdown {{ ansible_default_ipv4['interface'] }} && ifup {{ ansible_default_ipv4['interface'] }}"
      when: interface_domain_configuration.changed

azure_resolv.fact

#!/usr/bin/env bash

# we are assuming the parent domain stays the same
SEARCH=`grep -Eo '[[:alnum:].]+.internal.cloudapp.net' /etc/resolv.conf || :`

cat <<EOF
{
    "search_domain": "${SEARCH}"
}
EOF