---


###############################################
# Configure internet_interface to be gateway
###############################################

# Update sysctl.conf file to enable IP forwarding    
- name: sysctl - enable IP forwarding  
  lineinfile:
    path: /etc/sysctl.conf
    regexp: '^net.ipv4.ip_forward='
    line: 'net.ipv4.ip_forward=1'

# Apply sysctl changes
- name: sysctl - apply changes
  shell: sysctl -p

# Set up NAT with iptables
- name: NAT - iptables
  shell: iptables -t nat -A POSTROUTING -o {{ internet_interface }} -j MASQUERADE

# Set up Routing with IP Tables
- name: Routing - iptables
  shell: |
    iptables -A FORWARD -i {{ listen_interface }} -o {{ internet_interface }} -j ACCEPT
    iptables -A FORWARD -i {{ internet_interface }} -o {{ listen_interface }} -m state --state RELATED,ESTABLISHED -j ACCEPT

# Make iptables rules persistent
- name: Persistence - iptables
  shell: |
    netfilter-persistent save
    netfilter-persistent reload


...