infra/ansible/roles/firewall/tasks/main.yml

---
# Firewall configuration using ufw
# Default deny incoming, allow outgoing
# Trusted subnets get full access
# Per-host rules for publicly exposed services

- name: Install ufw
  apt:
    name: ufw
    state: present
    update_cache: true
  when: ansible_os_family == "Debian"

- name: Install firewalld
  dnf:
    name: firewalld
    state: present
  when: ansible_os_family == "RedHat"

- name: Ensure firewalld is started and enabled
  systemd:
    name: firewalld
    state: started
    enabled: true
  when: ansible_os_family == "RedHat"

# --- Firewalld (RedHat/AlmaLinux) ---

- name: Allow trusted subnets in firewalld
  ansible.posix.firewalld:
    zone: public
    source: "{{ item.subnet }}"
    permanent: true
    immediate: true
    state: enabled
  loop: "{{ firewall_trusted_subnets }}"
  when: ansible_os_family == "RedHat"

- name: Allow SSH from specific IPs in firewalld
  ansible.posix.firewalld:
    zone: public
    rich_rule: 'rule family="ipv4" source address="{{ item.ip }}" port port="22" protocol="tcp" accept'
    permanent: true
    immediate: true
    state: enabled
  loop: "{{ firewall_ssh_allow_from }}"
  when:
    - ansible_os_family == "RedHat"
    - firewall_ssh_allow_from | length > 0

- name: Allow per-host public services in firewalld
  ansible.posix.firewalld:
    zone: public
    port: "{{ item.port | string }}/{{ item.proto }}"
    permanent: true
    immediate: true
    state: enabled
  loop: "{{ firewall_allow_rules }}"
  when:
    - ansible_os_family == "RedHat"
    - firewall_allow_rules | length > 0

# --- UFW (Debian/Ubuntu) - Check current state ---

- name: "Check ufw status"
  ansible.builtin.command: ufw status
  register: _fw_ufw_active
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_os_family == "Debian"

# --- UFW (Debian/Ubuntu) - Disable when firewall not managed ---

- name: Disable ufw
  ufw:
    state: disabled
  when:
    - ansible_os_family == "Debian"
    - not (firewall_enabled | default(true))
    - _fw_ufw_active.stdout is defined
    - "'Status: active' in _fw_ufw_active.stdout"

# --- UFW (Debian/Ubuntu) - Configure when firewall managed ---

- name: Set default incoming policy to deny
  ufw:
    direction: incoming
    policy: "{{ firewall_default_incoming }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)

- name: Set default outgoing policy to allow
  ufw:
    direction: outgoing
    policy: "{{ firewall_default_outgoing }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)

- name: Set default routed policy
  ufw:
    direction: routed
    policy: "{{ firewall_default_routed }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)

- name: "Capture existing ufw rules"
  ansible.builtin.command: ufw status verbose
  register: _fw_ufw_rules
  changed_when: false
  failed_when: false
  check_mode: false
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - _fw_ufw_active.stdout is defined
    - "'Status: active' in _fw_ufw_active.stdout"

- name: Allow all traffic from trusted subnets
  ufw:
    rule: allow
    from_ip: "{{ item.subnet }}"
    comment: "{{ item.comment }}"
  loop: "{{ firewall_trusted_subnets }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - _fw_ufw_rules.skipped | default(true) or item.subnet not in _fw_ufw_rules.stdout

- name: Allow SSH from specific IPs
  ufw:
    rule: allow
    port: "22"
    proto: tcp
    from_ip: "{{ item.ip }}"
    comment: "SSH from {{ item.comment }}"
  loop: "{{ firewall_ssh_allow_from }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - firewall_ssh_allow_from | length > 0
    - _fw_ufw_rules.skipped | default(true) or item.ip not in _fw_ufw_rules.stdout

- name: Allow per-host public services
  ufw:
    rule: allow
    port: "{{ item.port | string }}"
    proto: "{{ item.proto }}"
    from_ip: "{{ item.from_ip | default('any') }}"
    comment: "{{ item.comment }}"
  loop: "{{ firewall_allow_rules }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - firewall_allow_rules | length > 0
    - _fw_ufw_rules.skipped | default(true) or (item.port | string + '/' + item.proto) not in _fw_ufw_rules.stdout

- name: Enable IP forwarding
  ansible.posix.sysctl:
    name: net.ipv4.ip_forward
    value: '1'
    sysctl_set: true
    state: present
    reload: true
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - firewall_ip_forward

- name: Configure NAT masquerade rules in ufw before.rules
  ansible.builtin.blockinfile:
    path: /etc/ufw/before.rules
    insertbefore: "\\*filter"
    marker: "# {mark} ANSIBLE MANAGED - {{ item.comment }}"
    block: |
      *nat
      :POSTROUTING ACCEPT [0:0]
      -A POSTROUTING -s {{ item.source }} -o {{ item.out_interface }} -j MASQUERADE -m comment --comment "{{ item.comment }}"
      COMMIT
  loop: "{{ firewall_masquerade_rules }}"
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - firewall_masquerade_rules | length > 0
  notify: Reload ufw

- name: Enable ufw
  ufw:
    state: enabled
  when:
    - ansible_os_family == "Debian"
    - firewall_enabled | default(true)
    - _fw_ufw_active.stdout is defined
    - "'Status: active' not in _fw_ufw_active.stdout"