Terraform Notes – Day 1 – 18 Sept 2023

==============================
AWS
==============================
CMD
	Windows
------------------------------------
A -> B --> C
------------------------------------
====================================================
Discuss --> Demo --> LAB
----------------  -------------
    20 mins	     30 mins

--------------------------------------------------------------------
What is Terraform?
---------------------------------------
	I A A C
	---------
	Coding for Infra

	Release
		community - cli - free [ FOCUS ]
		cloud - web - Paid
		Enterprise - web - paid
	
	Writren Go
		Platform ind - win  - linux - mac

	Hashicorp
	https://www.hashicorp.com/


What is Infra? - 3522
---------------------------------------
https://registry.terraform.io/browse/providers
	Servers - Networks -

AWS	-> CloudFormation	YAML	- only for AWS	
Azure	-> ARM			YAML	- only for Azure
Vmware
GC
Kubernetes

Why Terraform?
=================================
- CODE for All 
- ONE CODING STANDARD
- Consistent change managment
- Desire based (IDEOMPOTENT)
	Declare our desire(Yaml/Json|Xml) --> Tool 
			using 	HCL
			------------------
			Easy to learn - debug - test - extend - share 
=================================
How Terraform Works? 


How to install terraform?
Terraform Tutorials: Installation & Configurations


How to set environment variable using command line
Windows - cmd

$ set PATH "%PATH%;C:\tools\terraform";
$ setx PATH "%PATH%;C:\tools\terraform";

Windows - powershell
$env:PATH += ";C:\tools\terraform"

Linux - shell 
export PATH=$PATH:/opt/terraform

Gitbash - shell
export PATH=$PATH:/opt/terraform

================================================
How to download Terraform Providers?
-------------------------------------------------
Using Code
---------------------------
How to store terraform code?
- anyfilename.tf

In one directory, if we have one or multiple terraform code, its considered a ONE terraform code Only

		one.tf + two.tf + third.tf
		-------------------------
			oNe code

AWS
Azure
Github

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "5.17.0"
    }
  }
}

provider "aws" {
  # Configuration options
}

How to download?
-----------------------
$ terraform init

How to see list of providers downloaded
$ terraform providers


-------------------------
terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "5.17.0"
    }
	azurerm = {
      source = "hashicorp/azurerm"
      version = "3.73.0"
    }
	github = {
      source = "integrations/github"
      version = "5.37.0"
    }
  }
}

provider "aws" {
  # Configuration options
}


provider "azurerm" {
  # Configuration options
}


provider "github" {
  # Configuration options
}
--------------------------------

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/instance

https://registry.terraform.io/providers/hashicorp/aws/latest/docs

https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/virtual_machine

https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs

========================================================

API 
	Every feature - resource


AWS
	resource1
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional
	resource2
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional
	resource3
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional
Azure
	resource1
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional
	resource2
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional
	resource3
		arguments1	REQUIRED|Optional
		arguments2	REQUIRED|Optional
		arguments3	REQUIRED|Optional



Arguments MUST be one of these
---------------------------------
integ
string
bool
list
dict

aws.tf
---------------------------------------
resource "aws_instance" "web" {
  ami           = "ami-053b0d53c279acc90"
  instance_type = "t3.micro"

  tags = {
    Name = "HelloWorld-rajesh"
  }
}



$ terraform init
$ terraform validate
$ terraform plan
$ terraform apply
$ terraform show
$ terraform destroy

Single-line comments:
# begins a single-line comment, ending at the end of the line.
// also begins a single-line comment, as an alternative to #.

Multi-line comments:
/* and */ are start and end delimiters for a comment that might span over multiple lines.

=============================================================================
How to work with Another providers?
--------------------------------------
Step 1-  Add provider in tf code and Set AUTH

Step 2 - Add a resources of that part* providers

Step 3 - 

$ terraform init
$ terraform validate
$ terraform plan
$ terraform apply
$ terraform show
$ terraform destroy


https://www.devopsschool.com/blog/github-tutorials-how-to-generate-pat-in-github/

resource "github_repository" "example" {
  name        = "example-XBBSHSGSGSS"
  description = "My awesome codebase"

  visibility = "public"
}

provider "github" {
  token = "ddddddo1z"
}

Assignment

OUTPUT VALUES

=================================================================
OUTPUT Block which would display a vars from statefile.
---------------------------
https://www.devopsschool.com/blog/terraform-output-variable-example/

output "instance_public_ip" {
  value = aws_instance.web.public_ip
}



output "ec2_instance_ips" {
  value = [for instance in aws_instance.ec2_instances : instance.private_ip]
}

output "ec2_instance_pubips" {
  value = [for instance in aws_instance.ec2_instances : instance.public_ip]
}

output "instance_public_ip" {
  value = aws_instance.web.security_groups[0]
}

# How to display tags. Write a output block

output "github_repo_url" {
  value = github_repository.example.http_clone_url
}


$ terraform apply --auto-approve
$ terraform output

Terraform Provisionar

https://www.devopsschool.com/blog/terraform-provisioners-tutorials-and-complete-guide/
\https://developer.hashicorp.com/terraform/language/resources/provisioners/null_resource

file-exec	- COPY A file from HOST to the Vm created at AWS/Azure
			connection to vm
local-exec      - Running a cmd/script in HOST after vm created.
remote-exec	- Running a cmd/script in VM after vm created.
			connection to vm
Terrafrom – Example Code for remote-exec, local-exec & file provisioner