Ansible idempotent iptables add rule

main.yml

---
- name: Check forward udp port 53
  command: iptables -t nat -C PREROUTING -i {{ eth }} -p udp --dport 53 -j REDIRECT --to-port 8600
  register: result
  failed_when: False
  changed_when: False
  when: server
  tags: iptables

- name: Forward udp port 53
  command: iptables -t nat -A PREROUTING -i {{ eth }} -p udp --dport 53 -j REDIRECT --to-port 8600
  when: server and result|failed
  tags: iptables

- name: Check forward udp port 53 localhost
  command: iptables -t nat -C OUTPUT -o lo -p udp --dport 53 -j REDIRECT --to-ports 8600
  register: result
  failed_when: False
  changed_when: False
  when: server
  tags: iptables

- name: Forward udp port 53 localhost
  command: iptables -t nat -A OUTPUT -o lo -p udp --dport 53 -j REDIRECT --to-ports 8600
  when: server and result|failed
  tags: iptables