install-and-configure-cloudflare-dns-updater-service.yaml

---
- name: Install and configure Cloudflare DNS record updater service
  # https://community.cloudflare.com/t/update-dns-records-via-api/132221
  hosts: all
  gather_facts: true
  vars:
    service_file_name: cloudflare-dns-updater.service
    service_file_location: /etc/systemd/system/cloudflare-dns-updater.service
    timer_file_name: cloudflare-dns-updater.timer
    timer_file_location: /etc/systemd/system/cloudflare-dns-updater.timer
    service_script_location: /usr/local/bin/cloudflare-dns-record-update.sh
  tasks:
    - name: Required dependencies
      become: true
      apt:
        update_cache: yes
        pkg:
          - jq
        state: latest

    - name: "Remove {{ item }}"
      become: true
      file:
        path: "{{ item }}"
        state: absent
      with_items:
        - "{{ service_file_location }}"
        - "{{ timer_file_location }}"
        - "{{ service_script_location }}"

    - name: "Create {{ item }}"
      become: true
      file:
        path: "{{ item }}"
        state: touch
      with_items:
        - "{{ service_file_location }}"
        - "{{ timer_file_location }}"
        - "{{ service_script_location }}"

    - name: "Populate {{ service_file_location }} file"
      become: True
      blockinfile:
        path: "{{ service_file_location }}"
        block: |
          [Unit]
          Description=Cloudflare DNS Record Updater

          [Service]
          ExecStart=bash {{ service_script_location }}
          Restart=on-failure
          Type=oneshot
          User={{ ansible_user }}

          [Install]
          WantedBy=multi-user.target
    
    - name: "Populate {{ timer_file_location }} file"
      become: True
      blockinfile:
        path: "{{ timer_file_location }}"
        block: |
          [Unit]
          Description=Timer to run Cloudflare DNS Record Updater service every 4 hours

          [Timer]
          OnCalendar=00/4:00

          [Install]
          WantedBy=timers.target
 
    - name: "Populate {{ service_script_location }} file"
      become: True
      blockinfile:
        path: "{{ service_script_location }}"
        block: |
          #! /bin/bash

          # Inspired from this page https://gist.github.com/Tras2/cba88201b17d765ec065ccbedfb16d9a

          # Script to update a Cloudflare DNS record with the current public IP address
          # of the machine from which this script is run

          # Needs the DNS record pre-creating on Cloudflare

          # Cloudflare zone ID is the zone ID for the Zone which holds the record
          zone_id="{{ cloudflare.zone_id }}"

          # Auth details, this is the Bearer Token
          auth_key="{{ cloudflare.auth_key }}"

          # Domain name
          domain_name="{{ domain_name }}"

          # Get the current external IP address
          ip=$(curl -s -X GET https://checkip.amazonaws.com)
          echo "Current IP is ${ip}"

          cloudflare_api_base_url="https://api.cloudflare.com/client/v4"

          echo "Zone ID is ${zone_id}"

          dns_records=$(curl -s -X GET "${cloudflare_api_base_url}/zones/${zone_id}/dns_records" \
            -H "Authorization: Bearer ${auth_key}" \
            -H "Content-Type: application/json" | jq -r '{"result"}[]')

          echo "${dns_records[@]}" | jq -c '.[]' | while read dns_record; do
              dns_record_name=$(echo "${dns_record}" | jq -r '.name')
              if [[ "${dns_record_name}" != "*.${domain_name}" && "${dns_record_name}" != "${domain_name}" ]]; then
                  echo "Skipping '${dns_record_name}' cause it doesnt match '${domain_name}' and '*.${domain_name}'"
                  continue
              fi

              dns_record_ip=$(echo "${dns_record}" | jq -r '.content')
              if [ "${ip}" == "${dns_record_ip}" ]; then
                  echo "IP address for ${dns_record_name} is already ${ip}"
                  continue
              fi
              dns_record_id=$(echo "${dns_record}" | jq -r '.id')
              dns_record_type=$(echo "${dns_record}" | jq -r '.type')
              dns_record_ttl=$(echo "${dns_record}" | jq -r '.ttl')
              dns_record_proxied=$(echo "${dns_record}" | jq -r '.proxied')

              echo "DNS Record ${dns_record_name} has ID ${dns_record_id} and IP ${dns_record_ip}"

              echo "Updating ${dns_record_name} to ${ip}"
              curl -s -X PUT "${cloudflare_api_base_url}/zones/${zone_id}/dns_records/${dns_record_id}" \
                -H "Authorization: Bearer ${auth_key}" \
                -H "Content-Type: application/json" \
                --data '{"type":"'${dns_record_type}'","name":"'${dns_record_name}'","content":"'${ip}'","ttl":'${dns_record_ttl}',"proxied":'${dns_record_proxied}'}'
          done

    - name: "Reload Systemd timer {{ timer_file_name }}"
      include_tasks: tasks-reload-systemd-service.yaml
      vars:
        become: True
        service_name: "{{ timer_file_name }}"