Ansible playbook for the *very first* connection to a newly-provisioned VPS

setup_accounts.yml

---

##############################################################
#
# setup_accounts.yml
#
# This Ansible playbook configures the accounts for an initial
#   connection to a newly provisioned VPS. It performs the following tasks:
#
#  1. Log into the target server using the root password (not public key)
#  2. Create a 'deploy' user
#  3. Install the SSH public key from your account/home directory
#  4. Add 'deploy' to /etc/sudoers to enable sudo access
#  5. Disallow password login for all accounts
#  6. Disallow root ssh access
#  7. (Leave ssh port set to default of 22 - commented out)
#
# The script ssh's into the host and uses the root password for 
#   authentication. It can never be re-run on the host because
#   passwords and root access are both disallowed.
#
# You only need to run this playbook one time for a new VPS. After that
#   all future connections to the host should use the 'deploy' user.
# 
# ----------------
#
# To run the script, enter the following command:
#
# ansible-playbook -i "hostname," setup_accounts.yml -k  
#
# Substitute the hostname as needed (keep the trailing comma (",").
# You will be prompted to enter the root password, then you will be
#   prompted to enter a password (twice) for the 'deploy' user.
#
# If you see "Please add this host's fingerprint to your known_hosts file"
#   you need to ssh root@hostname one time to set the fingerprint. 
#   Then re-run the ansible-playbook command (above)
# 
# ----------------
#
# Copyright (c) 2020 Rich Brown
# Blueberry Hill Software 
# rich.brown@blueberryhillsoftware.com
# GPL v2 - use it, enjoy it, and let me know if it helps!
#
# Provenance: Original ideas came from:
# https://github.com/jedelman8/server-build-ansible/blob/master/server_one_time_run.yml
# referred from http://jedelman.com/home/server-bootstrap-prep-with-ansible/
# Seasoned with info from Ryan Eschinger's first-time setup
# Those playbooks needed to be refreshed for the (current) Ansible 2.9 syntax
# Tested with Ansible 2.9.6 - 6Apr2020 
#
##############################################################

- name: Set Up Accounts on a New Host (First run - never again)
  hosts: all
  gather_facts: no
  remote_user: root

  vars_prompt:
    - name: deploy_password
      prompt: "What is the password for the 'deploy' user?"
      private: yes
    - name: deploy_password2
      prompt: "  Enter the 'deploy' password one more time"
      private: yes

  vars:
      ubuntu_common_deploy_user_name: deploy
      hashed_password:  "{{ deploy_password | password_hash('sha512') }}"
      copy_of_my_ssh_key: "{{ lookup('file', lookup('env','HOME') + '/.ssh/id_rsa.pub') }}"
#     ubuntu_common_ssh_port: 22

  tasks:

   #check if params are valid: abort the remaining tasks if not
  - assert: 
      that: 
        - deploy_password is defined
        - deploy_password2 is defined
        - deploy_password == deploy_password2
      success_msg: "Passwords are OK"
      fail_msg: "Passwords are missing or do not match"

  - name: 'Add deploy user'
    user: name={{ ubuntu_common_deploy_user_name }} password="{{ hashed_password }}" shell=/bin/bash

  - name: 'Add authorized key taken from HOME public key'
    authorized_key:
      user: deploy
      state: present
      key: "{{ copy_of_my_ssh_key }}"

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

  - 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

  # - name: 'Change ssh port'
  #   lineinfile: dest=/etc/ssh/sshd_config
  #                 regexp="^Port\s"
  #                 line="Port {{ ubuntu_common_ssh_port }}"
  #                 state=present
  #   notify: Restart ssh

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