This will do the basic setup after getting your hands on a new server. It will create a new user, disable the root user and install/configure ufw, fail2ban, logwatch and postfix.

serverSetup.yml

# Based on: https://ryaneschinger.com/blog/securing-a-server-with-ansible/

- hosts: all
  gather_facts: false

  pre_tasks:
  - name: install python needed for ansible modules to work
    raw: sudo bash -c "test -e /usr/bin/python || (apt -qqy update && apt install -qy python-minimal)"

  tasks:
    - name: Include vars from config.yml.
      include_vars:
        file: config.yml

    - name: Add server user
      user: name={{ ubuntu_common_server_user_name }}
            password="{{ ubuntu_common_server_password | password_hash('sha512') }}"
            shell=/bin/bash
            update_password=always

    - name: Add authorized keys for server user
      authorized_key: user={{ ubuntu_common_server_user_name }} key="{{ lookup('file', item) }}"
      with_items: "{{ ubuntu_common_server_public_keys }}"

    - name: Add server user to sudoers
      lineinfile: dest=/etc/sudoers
                  regexp="{{ ubuntu_common_server_user_name }} ALL"
                  line="{{ ubuntu_common_server_user_name }} ALL=(ALL) ALL"
                  state=present

    - name: update APT package cache
      apt: update_cache=yes cache_valid_time=3600

    - name: Upgrade APT to the latest packages
      apt: upgrade=safe

    - name: Install required packages
      apt: state=installed pkg={{ item }}
      with_items:
        "{{ ubuntu_common_required_packages }}"

    - name: Setup ufw
      ufw: state=enabled policy=deny

    - name: Allow ssh traffic
      ufw: rule=allow port={{ ubuntu_common_ssh_port}} proto=tcp

    - name: Set up Postfix to relay mail
      debconf: name=postfix
              question='{{ item.question }}'
              value='{{ item.value }}'
              vtype='{{ item.vtype }}'
      with_items:
        - { question: 'postfix/mailname', value: "{{ postfix_mailname_domain }}", vtype: 'string' }
        - { question: 'postfix/main_mailer_type', value: 'Internet Site', vtype: 'string' }

    - name: Email log summary daily
      lineinfile: dest=/etc/cron.daily/00logwatch
                 regexp="^/usr/sbin/logwatch"
                 line="/usr/sbin/logwatch --output mail --mailto {{ ubuntu_common_logwatch_email }} --detail high"
                 state=present create=yes

    - name: Disallow password authentication
      lineinfile: dest=/etc/ssh/sshd_config
                  regexp="^PasswordAuthentication"
                  line="PasswordAuthentication no"
                  state=present
      notify: Restart ssh

    - name: Disallow root SSH access
      lineinfile: dest=/etc/ssh/sshd_config
                 regexp="^PermitRootLogin"
                 line="PermitRootLogin no"
                 state=present
      notify: Restart ssh
      tags:
        - danger

  handlers:
    - name: Restart ssh
      service: name=ssh state=restarted