checkmk_deploy_agent/tasks/Debian.yml

---
# ============================================================================
# Package Installation Tasks
# ============================================================================

- name: "{{ ansible_os_family }} Derivatives: Install host-specific {{ checkmk_agent_edition | upper }} Agent."
  become: true
  ansible.builtin.apt:
    deb: "{{ __checkmk_agent_agent.file.host }}"
    force: "{{ checkmk_agent_force_install | bool }}"
    state: present
  when: |
    checkmk_agent_edition | lower != "cre"
    and checkmk_agent_host_specific | bool
  failed_when: false  # Ignore if a newer version is already installed
  tags:
    - install-package

- name: "{{ ansible_os_family }} Derivatives: Install GENERIC or folder-specific {{ checkmk_agent_edition | upper }} Agent."
  become: true
  ansible.builtin.apt:
    deb: "{{ __checkmk_agent_agent.file.cee }}"
    force: "{{ checkmk_agent_force_install | bool }}"
    state: present
  when: |
    checkmk_agent_edition | lower != "cre"
    and not checkmk_agent_host_specific | bool
  failed_when: false  # Ignore if a newer version is already installed
  tags:
    - install-package

- name: "{{ ansible_os_family }} Derivatives: Transfer Vanilla agent."
  ansible.builtin.copy:
    src: "{{ __checkmk_agent_agent.file.cre }}"
    dest: "{{ __checkmk_agent_agent.file.cre }}"
    mode: "0644"
  when: |
    checkmk_agent_edition | lower == "cre"
    and checkmk_agent_delegate_download != inventory_hostname
  tags:
    - download-package

- name: "{{ ansible_os_family }} Derivatives: Install Vanilla agent."
  become: true
  ansible.builtin.apt:
    deb: "{{ __checkmk_agent_agent.file.cre }}"
    force: "{{ checkmk_agent_force_install | bool }}"
    state: present
  when: checkmk_agent_edition | lower == "cre"
  failed_when: false  # Ignore if a newer version is already installed
  tags:
    - install-package

# ============================================================================
# Firewall Configuration Tasks
# ============================================================================
# These tasks only run if UFW is installed, enabled in config, AND already active.
# We don't want to accidentally enable UFW if it's not currently running.
# ============================================================================

- name: "{{ ansible_os_family }}: Check if UFW is active."
  become: true
  ansible.builtin.command: ufw status
  register: __checkmk_agent_ufw_status
  changed_when: false  # Status check should never report as changed
  failed_when: false   # Don't fail if UFW is not installed
  when: checkmk_agent_configure_firewall | bool and "ufw" in ansible_facts.services
  tags:
    - configure-firewall

- name: "{{ ansible_os_family }} Configure Firewall for Agent."
  # Opens port 6556/tcp for CheckMK agent communication
  # Only runs if UFW is already active to avoid accidentally enabling firewall
  become: true
  ansible.builtin.raw: |
    ufw allow 6556/tcp
    ufw reload
  args:
    executable: /bin/bash
  register: __checkmk_agent_ufw_result
  changed_when: "'Skipping' not in __checkmk_agent_ufw_result.stdout"
  when: |
    checkmk_agent_configure_firewall | bool 
    and "ufw" in ansible_facts.services
    and __checkmk_agent_ufw_status is defined
    and 'Status: active' in __checkmk_agent_ufw_status.stdout
  tags:
    - configure-firewall

- name: "{{ ansible_os_family }} Derivatives: Configure Firewall for Agent with IP restrictions."
  # This block adds IP-specific firewall rules for the CheckMK server
  # It handles both direct IP addresses and hostnames (which get resolved via DNS)
  when: |
    checkmk_agent_configure_firewall | bool 
    and "ufw" in ansible_facts.services
    and __checkmk_agent_ufw_status is defined
    and 'Status: active' in __checkmk_agent_ufw_status.stdout
  block:
    - name: "{{ ansible_os_family }} Derivatives: Add Checkmk Server to Firewall Whitelist if it is an IP address."
      # Uses regex to detect if checkmk_agent_server is already an IP (IPv4 or IPv6)
      # Regex pattern matches: IPv4 (x.x.x.x) or IPv6 (xxxx:xxxx:...)
      when: checkmk_agent_server | regex_search('^([0-9]{1,3}\.){3}[0-9]{1,3}$|^([0-9a-fA-F:]+:+)+[0-9a-fA-F]+$')
      ansible.builtin.set_fact:
        checkmk_agent_server_ips: "{{ checkmk_agent_server_ips | default([]) + [checkmk_agent_server] }}"

    - name: "{{ ansible_os_family }} Derivatives: Resolve Checkmk Server hostname to IPs if it's not an IP."
      # If checkmk_agent_server is a hostname (e.g., monitoring.gc-gruppe.net),
      # resolve it to IP address(es) via getent (standard Linux tool, no extra dependencies)
      # This ensures firewall rules work even when using hostnames
      when: not (checkmk_agent_server | regex_search('^([0-9]{1,3}\.){3}[0-9]{1,3}$|^([0-9a-fA-F:]+:+)+[0-9a-fA-F]+$'))
      become: true
      ansible.builtin.shell: "getent hosts {{ checkmk_agent_server }} | awk '{ print $1 }' | head -n1"
      register: __checkmk_agent_server_resolved
      changed_when: false

    - name: "{{ ansible_os_family }} Derivatives: Set resolved IP as fact."
      # Store the resolved IP address for use in firewall rules
      when: 
        - __checkmk_agent_server_resolved is defined
        - __checkmk_agent_server_resolved.stdout | length > 0
      ansible.builtin.set_fact:
        checkmk_agent_server_ips: "{{ checkmk_agent_server_ips | default([]) + [__checkmk_agent_server_resolved.stdout] }}"

    - name: "{{ ansible_os_family }} Derivatives: Allow Checkmk services access to the agent."
      # Creates UFW rules allowing each CheckMK server IP to connect to port 6556
      # Loops through all resolved/provided IPs and adds individual rules
      # Each rule gets a comment for easy identification in 'ufw status'
      when: checkmk_agent_server_ips is defined and checkmk_agent_server_ips | length > 0
      become: true
      ansible.builtin.raw: |
        ufw allow from {{ item }} to any port 6556 proto tcp comment 'Allow Checkmk'
        ufw reload
      args:
        executable: /bin/bash
      loop: "{{ checkmk_agent_server_ips }}"
      register: __checkmk_agent_ufw_rich_result
      changed_when: "'Skipping' not in __checkmk_agent_ufw_rich_result.stdout"
  tags:
    - configure-firewall