Terraform Hands-on Repository

A collection of Hands-on labs for Terraform.
Each lab is a standalone lab and does not require to complete the previous labs.

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Pre-Requirements

This tutorial will walk you using terraform locally without any requirements for any cloud provider.
If you are using GCP all the tools are pre-installed

Terraform	Kubernetes	Minikube	Helm	kubectl

Tool	Comments
K8S	An existing cluster or any other local tool as described here
kubectl	The Kubernetes command-line tool, kubectl
minikube	Local cluster for running the hands on labs
Helm	Some of the demos will require helm charts installed
Terraform	This is what this tutorial is about ...

What is Terraform?

IAC - Infrastructure As Code
Open Source developed by HashiCorp
Declarative language - Define what you want and terraform will "get" there, terraform will figure out how to create what you wish.
Terraform is mainly for Infrastructure (IAC)
Terraform is based upon modules

Terraform Key Features

Infrastructure as a Code
- Infrastructure is described using a high-level configuration syntax with HCL files.
- Due to the fact that HCL are text files they can be stores in SCM (GIT for example) in a branch level, this ability allow to share, reuse, versioned and more.
Execution Plans
- terraform plan generates an execution plan (JSON file).
- Since this a text file (JSON) as mentioned above it can be stored in SCM (GIT for example) and can versioned, shared and more.
- The execution plan calculate the "difference" between the current state to the desired state.
- The plan describe exactly what Terraform will change and in what order which make it clear what will happen.
Resource Graph
- Terraform builds a graph of all your resources.
- Terraform try to execute the required changes in parallel of any non-dependent resources.
- terraform graph generate a DOT (DOT is a graph description language) files which can be converted to svg images for example.
- ```
# Generate a graph based upon the execution plan
# require dot to be installed,

### MacOs
    brew install graphviz
### Linux
    sudo apt-get install graphviz

terraform graph | dot -Tsvg > graph.svg
```
Automation
- Terraform as IAC (Infrastructure as code) tool, and as such it designed for making automated changes or with a minimal human interaction.
- Terraform support using templates for re-use code. In this way we it support multiple environments, providers by writing a simple syntax.

Terraform Architecture

Terraform is build upon 2 main components:
- Core
- State
User write the desired code, terraform calculate the desired result and execute it using the selected provider.
In the following labs we will learn how to work with Terraform

List of the labs in this repository:

📗 00-Setup

CLI commands

📗 01-init
📗 02-get
📗 03-validate
📗 04-plan
📗 05-apply
📗 06-destroy
📗 07-refresh
📗 09-import
📗 10-state
📗 11-workspace
📗 12-graph
📗 02-Variables
📗 03-Getting-Started-Kubernetes
📗 04-Getting-Started-Helm-Chart