0_prepare_cluster.yml

---
# Prepares the cluster to be securely accessed by ansible controllers without password
# Creates an admin account in every cluster node
# File: 0_prepare_cluster.yml

- hosts: ansible-controllers
  serial: 1
  become: yes
  become_user: root

  
  vars_prompt:
  
    - name: "admin_user"
      prompt: "Enter username for the cluster administrator account:"
      private: no
      confirm: yes
      
    - name: "admin_pass"
      prompt: "Enter password for the cluster administrator account:"
      private: yes
      confirm: yes
      encrypt: "sha256_crypt"
  
  tasks:
  
    - name: install/update epel-release
      yum:
        name: epel-release
        state: latest
      tags: epel

    - name: install pip
      yum:
        name: python-pip
        state: latest
      tags: pip

    - name: install pexpect
      command: pip install pexpect
      tags: pexpect
    
    - name: create group 'clusteradmins'
      group:
        name: clusteradmins
        state: present
      delegate_to: "{{ item }}"
      loop: "{{ groups['all'] }}"
        
    - name: everyone in group 'clusteradmins' can sudo
      lineinfile:
        path: /etc/sudoers
        regexp: '^%clusteradmins ALL=\(ALL\) ALL'
        line: "%clusteradmins ALL=(ALL) ALL"
      delegate_to: "{{ item }}"
      loop: "{{ groups['all'] }}"
    
    - name: create cluster administrator user in all hosts
      user:
        name: "{{ admin_user }}"
        state: present
        group: clusteradmins
        password: "{{ admin_pass }}"
      delegate_to: "{{ item }}"
      loop: "{{ groups['all'] }}"
    
    - name: generate ssh key
      user:
        name: "{{ admin_user }}"
        generate_ssh_key: yes
        ssh_key_file: /home/{{ admin_user }}/.ssh/id_rsa
        ssh_key_comment: "{{ admin_user }} on {{ ansible_nodename }}"
      register: user
      
    - name: add key to authorized keys in hosts
      authorized_key:
        user: "{{ admin_user }}"
        state: present
        key: "{{ user.ssh_public_key }}"
      delegate_to: "{{ item }}"
      loop: "{{ groups['all'] }}"
      
...