https://devopsideas.com/series/ansible-tutorial/
https://devopsideas.com/ansible-local-setup-using-vagrant-virtualbox/
SSH Issue:  https://hvops.com/articles/ansible-post-install/

Create LAB environment with Vagrant (see section below)
> vagrant up

INSTALL ANSIBLE ON BASTION SERVER
=================================
https://github.com/leucos/ansible-tuto


> vagrant ssh bastion
#<scripted vagrantfile> sudo yum -y install ansible
#<scripted vagrantfile> sudo yum -y install nano
#<scripted vagrantfile> su root >> to amend ansible inventory file
#<scripted vagrantfile> inventory      = /etc/ansible/hosts
[app]
192.168.33.21
192.168.33.22
[db]
192.168.33.23
[all:children]
app
db
-----------------------------------

Example 2 Ansible Host File:
[control]
tower ansible_host=10.42.0.2

[web]
node-[1:3] ansible_host=10.42.0.[6:8]

[haproxy]
haproxy ansible_host=10.42.0.100

[all:vars]
ansible_user=vagrant
ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key
------------------------------------


MANUALS SETUP>>

1. CONFIGURE SSH FOR ALL MANAGED SERVERS
========================================
> vagrant ssh <managed servers: app1, app2, db>
$ su root
$ vi /etc/ssh/sshd_config
'PasswordAuthentication yes'
'PermitRootLogin yes'
$ sudo systemctl restart sshd
NOTE:  This can be included in Vagranfile with priviledge user script such as:
sed -i 's/PasswordAuthentication no'/PasswordAuthentication yes/g' /etc/ssh/sshd_config

2. SETUP BASTION HOST SSH KEY FOR ALL MANAGED SERVERS
=====================================================
> vagrant ssh bastion
$ vagrant@bastion:~# ssh-keygen -t rsa -C "name@example.org"
$ vagrant@bastion:~# ssh-copy-id vagrant@192.168.33.21
$ vagrant@bastion:~# ssh-copy-id vagrant@192.168.33.22
$ vagrant@bastion:~# ssh-copy-id vagrant@192.168.33.23

Testing with Ansible Ad-Hoc Commands
====================================
$ ansible all -m ping
$ ansible app -i /etc/ansible/hosts -m ping
$ ansible db -i /etc/ansible/hosts -m ping

$ ansible db -m copy -a "src=test.txt dest=/tmp/"
$ ansible db -m file -a "dest=/tmp/test.txt state=absent"
$ ansible web -m shell -a 'cat /etc/centos-release'
$ ansible -m command -a "ls /" db
$ ansible web -m command -a "uptime"
$ ansible web -m setup > output.txt
$ ansible -i myfolder/hosts -m setup -a 'filter=ansible_memtotal_mb' all

$ ansible all --list-hosts
$ ansible --list-hosts app

Testing with Ansible Playbooks
==============================
$ ansible-playbook play1.yml --check
$ ansible-playbook play1.yml --syntax-check
$ ansible-playbook play1.yml
$ ansible-playbook play1.yml -i ./hosts

Example Playbook 1
==================
---
- hosts: db
  tasks:
  - name: check if packages are installed
    yum: list="{{ item }}"
    with_items:
      - acpid
      - c-ares
      - automake
   register: packages
  - debug:
      var: packages

Example Playbook 2
==================
---
- name: Ansible playbook example 1
  hosts: db

  tasks:
   - name: List installed cups packages register result to print with debug later.
     yum:
       list=cups-lib*
     register: yum_result
   - debug:
       msg: "Installed packages {{ yum_result }}"

   - name: Run shell command "ls /"
     shell: ls /
     register: shell_out
   - debug:
       msg: "{{ shell_out }}"

   - name: Print variables
     debug:
       msg:
        - "ansible_distribution {{ hostvars[inventory_hostname].ansible_distribution }}"
        - "major version {{ hostvars[inventory_hostname].ansible_distribution_major_version }}"
        - "version {{ hostvars[inventory_hostname].ansible_distribution_version }}"

Example Playbook 3
==================
---
- name: install and start apache
  hosts: web
  become: yes
  vars:
    webserver: httpd

  tasks:
  - name: "{{ webserver }} package is present"
    yum:
      name: "{{ webserver }}"
      state: latest
    notify: restart webserver

  - name: latest index.html file is present
    copy:
      src: files/index.html
      dest: /var/www/html/

  handlers:
  - name: restart webserver
    service:
      name: "{{ webserver }}"
      state: restarted

Ansible Tools
=============
ansible				>> Run a single task
ansible-playbook	>> Run a playbook
ansible-vault		>> Encrypt/decrypt ansible data files
ansible-galaxy		>> CLI to manage ansible roles and the framework for ansible roles
ansible-console		>> REPL console for executing Ansible tasks
ansible-config		>> View/edit/manage ansible configuration
ansible-doc			>> Ansible documentation
ansible-inventory	>> Show ansible inventory information
ansible-pull		>> Pull ansible playbook from repository


[vagrant@bastion playbooks]$ ansible db -m yum -a "list=cups-pk*"
192.168.33.23 | SUCCESS => {
    "changed": false,
    "results": [
        {
            "arch": "x86_64",
            "envra": "0:cups-pk-helper-0.2.6-2.el7.x86_64",
            "epoch": "0",
            "name": "cups-pk-helper",
            "release": "2.el7",
            "repo": "base",
            "version": "0.2.6",
            "yumstate": "available"
        }
    ]
}
[vagrant@bastion playbooks]$ ansible-console db
Vault password:
Welcome to the ansible console.
Type help or ? to list commands.

vagrant@db (1)[f:5]$ yum list=cups-pk*
192.168.33.23 | SUCCESS => {
    "changed": false,
    "results": [
        {
            "arch": "x86_64",
            "envra": "0:cups-pk-helper-0.2.6-2.el7.x86_64",
            "epoch": "0",
            "name": "cups-pk-helper",
            "release": "2.el7",
            "repo": "base",
            "version": "0.2.6",
            "yumstate": "available"
        }
    ]
}


=================================================================================================================================
CREATE LAB ENVIRONMENT
----------------------
> md mylab
> cd mylab
> vagrant init ## create vagrantfile
> ## Modify generated vagrantfile
----------------------------------------------------------------
Vagrant.configure .... do |config|

config.ssh.insert_key = false

config.vm.provider "virtualbox" do |v|
  v.customize ["modifyvm", :id, "--cpuexecutioncap", "50", "--memory", "256"]
end

# Ansible Server
config.vm.define "bastion" do |bastion|
  bastion.vm.hostname = "bastion.dev"
  bastion.vm.box = "centos/7"
  bastion.vm.network "private_network", ip: "192.168.33.10"
  bastion.vm.provider :virtualbox do |vb|
    vb.customize ["modifyvm", :id, "--cpus", 1, "--cpuexecutioncap", "100", "--memory", 1024]
  end
end

# Application server 1.
config.vm.define "app1" do |app|
  app.vm.hostname = "app1.dev"
  app.vm.box = "centos/7"
  app.vm.network "private_network", ip: "192.168.33.21"
end

# Application server 2.
config.vm.define "app2" do |app|
  app.vm.hostname = "app2.dev"
  app.vm.box = "centos/7"
  app.vm.network "private_network", ip: "192.168.33.22"
end

# Database server.
config.vm.define "db" do |db|
  db.vm.hostname = "db.dev"
  db.vm.box = "centos/7"
  db.vm.network "private_network", ip: "192.168.33.23"
end

end
----------------------------------------------------------------
> vagrant up