# Wizardlab: How it Works

The Wizardlab project consists of a multi-machine Vagrantfile, a collection of
Ansible playbooks, and a Makefile

## The Makefile

I define how to configure the VMs with Ansible through a Makefile. The Makefile
that instructs make (`man make`) to execute targets. This utility is typically
used for defining how to compile source-code into binary executable files, but we
use it as another layer of automation. See [wizardlab/Makefile](https://github.com/ashemath/wizardlab/blob/main/Makefile)

While working out of either `/home/vagrant` or `/vagrant/` This command will run 
a playbook that regenerates SSH keys

```
$ make keys

```

While this one will setup a Debian PXE installation environment
```
$ make pxe

```
This takes things a step further, and we setup a Clonezilla based imaging
environment.
```
$ make imaging
```
Instead of playing with PXE, stand up DNS, DHCP, and Docker like so:
```
$ make docker_lab
```

Wizardlab is designed to automate standing up a set of services, so
you can get right into your configuration idea. 

## An Example Ansible Directory Structure

Ansible configuration directories can be organized a number of ways, but let's
suppose I have two roles (role0 and role1) that I design to setup two services:
service0 and service1.

I might have a testing inventory called test-inventory, and a folder
with various 'production' host inventory files organized by infrastrucure
context. 
For example 1-cluster targets machines in the compute cluster while 
3-research.yml targets research desktops.
Adopting a folder structure like the one below allows us to tap into
features of ansible that help us build very adaptive deployment strategies. 

```
test-inventory          #  If we pass a single file as the inventory, it runs just one. 
inventory/              #  If you pass a folder as your inventory file, it runs multiple.
  0-desktops            #  We can prefix our files to manipulate the order
  1-cluster             #  ini format is a row separated list of hosts, "simple"
  2-openstack.yml       #  yml format is avaiable too. Nice for compicated structures.
  3-research.yml        #  Pick a format you like. Either one works the same.
  group_vars/           #  Have multiple files to organize variables to apply to groups.
    all.yml             #  Variables that will be supplied to the special 'all' group.
    services.yml        #  Variables that will be supplied to only the 'services' group.
playbooks/              #  Not a special folder name. Here I am grouping a set of roles 
  role0/                #  This folder groups all the resources for a configuration together
    tasks/              #  Special folder name
      main.yml          #  The tasks in this file will run when role0 applies to a group. 
    files/              #  Special folder name
      service0.conf     #  You may hardcode a configuration file
    templates/          #  Special folder name
      service.conf.j2   #  Or, you may create a template instead. End files in .j2 
    vars/               #  Special folder name
      main.yml          #  The variables specific to this role
  role1/                #  We may develop as many roles we like.
  ...
```
## Wizardlab's file structure

I try to stick to the prescribed structure, but I prefer to use only a subset
of the special role-associated folders: tasks, files, templates. I may be
adding some handlers in the near future.
Since the Vagrantfile only stands up a few VMs, we use a single inventory file.
```
inventory               #  ini format inventory of the Vagrant machines
playbooks/
  controller/           #  Role for the controller
    tasks/
    files/              #  Role for configuring Docker
  docker/
    tasks/
    files/
  infra/                #  Role for DHCP/DNS
    tasks/
    templates/
  pxe/                  #  Role for Debian PXE intaller
    tasks/
    templates/
    files/
  clonezilla/           #  Role for Clonezilla imaging environment
    tasks/
    templates/
    files/
  fog/                  #  Role for Fog imaging environment
  windows/              #  Role for Windows configuration management
    tasks/
    vars/
```