This document provides an overview of infrastructure as code using Terraform. It introduces infrastructure as code and its benefits like standardization, reproducibility, and versioning. It then covers Terraform specifically, explaining concepts like providers, resources, provisioners, variables, modules, and more. It concludes with recommendations and pointers to additional material for learning Terraform.

1. Infrastructure As
Code
by Mario Inga

2. Quién soy?
• Mario Inga Cahuana
• Software Developer
• Miembro de: DevOps Perú, Docker Lima y Cloud Native
Perú
• Trabajo en BlazingSQL
• Metal m/
• @mario21ic

3. Agenda
• Infrastructure as code
• Intro a Terraform
• Providers
• Provisioners
• State
• Modules
• Workshop

4. The problem
• Environment like Prod
• Replication
• Fragile
• Versioning
• Documentation
• Testing

5. VPC Basica

6. Infrastructure as Code
• Es una buena práctica donde se describa y maneja
Infraestructura desde código.
• Normalmente se usa un lenguaje de alto nivel.
• También se aplican buenas prácticas de desarrollo de
software como:
• Versionado mediante SCM.
• Testing.

7. Infrastructure as Code
• Garantía en homogeneidad
• Tiempo para recuperación
• Productividad
• Asegurarse estándares
• Replicación
• Versionado
• Testing

8. IaC Tools
Google
Deployment Manager

9. Terraform
• Execution plans
• Resource graph
• Agnostic
• HCL is the HashiCorp configuration language.
• Development with Go and Open source
https://github.com/hashicorp/terraform

10. Simple & Powerful
• Write
• Collaborate & share
• Evolve your infrastructure
• Automation friendly
• Plan
• Map resource dependencies
• Separation plan & apply
• One safe workflow
• Create
• Environment parity
• Shareable modules
• Combine multiples providers consistenly

11. Example EC2
provider "aws" {
region = "us-west-2"
}
resource "aws_instance" "web" {
ami = "ami-06f2f779464715dc5"
instance_type = "t2.micro"
tags = {
Name = "HelloWorld"
}
}

12. Example VPC
provider "aws" {
region = "us-west-2"
}
resource "aws_vpc" "vpc" {
cidr_block = "10.0.0.0/16"
instance_tenancy = "default"
enable_dns_support = true
enable_dns_hostnames = true
}

13. Providers
• IaaS (e.g. AWS, GCP, Azure, OpenStack)
• PaaS (e.g. Heroku)
• SaaS (e.g. Atlas, DNSimple, Cloudflare).
• https://www.terraform.io/docs/providers/

14. Provisioners
• Used to execute scripts on a local or remote
machine as part of resource creation or
destruction.
• Can be used to bootstrap a resource, cleanup
before destroy, run configuration management, etc.
• There are: chef, connection, file, local-exec,
remote-exec, null_resource

15. Provisioners
resource "aws_instance" "web" {
connection {
user = "ubuntu"
type = "ssh"
private_key = "${file("agiles2019.pem")}"
timeout = "2m"
}
provisioner "remote-exec" {
inline = [
"export PATH=$PATH:/usr/bin",
"sudo apt-get update",
"sudo apt-get -y install nginx"
]
}

16. HCL - Provider

17. HCL - Resource

19. Workshop

20. Workshop
• Instalar Terraform: https://www.terraform.io/downloads.html
• Configurar aws credenciales: $ aws configure
• Clonar repositorio: https://github.com/mario21ic/
agilesperu2019-iac
• Acceder e iniciar:
$ cd agilesperu2019-iac/ && terraform init
• Aplicar:
$ terraform apply

21. Stacks
• Plan:
$ terraform plan
$ terraform plan -destroy
• Create / Modify:
$ terraform apply
• Delete:
$ terraform destroy

22. Targets
• Plan:
• $ terraform plan -target=aws_instance.web
• terraform plan -destroy -target=aws_instance.web
• Destroy
• terraform destroy -target=aws_instance.web
• Show
• $ terraform show -target=aws_instance.web

23. State
• Files:
• terraform.tfstate
• terraform.tfstate.backup
• State en S3:
terraform {
backend "s3" {
bucket = "mybucket.terraform"
key = "infrav1/terraform.tfstate"
region = "us-west-2"
}
required_version = ">0.9.4"
}

24. State
• List:
$ terraform state list
• Show:
$ terraform state show aws_instance.web
• Remove
$ terraform state rm aws_instance.web

25. Variables
• String
• List
• Map
• Boolean
• Integer
variable "region" {
type = "string"
description = "aws region"
default = "us-west-2"
}
variable "mylist" {
type = "list"
default = [80,8080,8089]
}
variable "mymap" {
type = "map"
default = {
nombre = "myvar"
puerto = 80
}
}

26. Variables input file
• Default: terraform.tfvars
• Alternative: -var-file="dev.tfvars"
region = "eu-west-1"
name = "dev"
# VPC
vpc_cidr = "10.0.0.0/16"

27. Output
• No more aws cli
• No more tricks
• $ terraform output
• Use:
output "ec2_ip" {
value = “${aws_instance.web.id}"
}
“${module.web.ec2_id}"

28. Environments
• List:
$ terraform workspace list
• Create
$ terraform workspace new dev
• Select
$ terraform workspace select dev

29. Filters data
• No more aws cli
• No more tags
• No more tricks
• Use:
data "aws_ami" "ami" {
most_recent = true
owners = ["self"]
filter {
name = "name"
values = ["mynginx"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
}
"${data.aws_ami.ami.id}"

30. Module
• DRY, Don't Repeat Yourself https://registry.terraform.io
• Tip: siempre probar que el recetario funcione solo y luego usarlo como
modulo, no olvidar exportar valores como ids mediante output.
• Supports:
• Local file paths
• Github
• Bitbucket
• Http urls
• S3

31. Module
• Iniciar: $ terraform init
• Download: terraform get -update=true
module "vpc" {
source = "github.com/mario21ic/terraform-aws-vpc"
region = "${var.region}"
name = "${var.name}"
…
}

32. All files in one
• main.tf -> recetario principal
• data.tf -> filtros para reutilizar recursos
• provider.tf -> configuración de providers
• variables.tf -> declaración de variables
• terraform.tfvars -> valor de variables por default
• outputs.tf -> valores a exportar
• consul.tf -> consul_keys de lectura y escritura

33. Recomendaciones
• Pensar en modulos reutilisables.
• Separar en recetarios: la red (vpc, subnets, security group, etc) de los
componentes (rds, elasticache, etc) y roles/usuarios (iam).
• Almacenar los valores (ids) de cada recetario en un storage como Consul o
Vault.
• Automatizar solo lo que genere valor.
• Usar un storage para los states como consul o s3.
• La nube no la controlamos al 100%, ejem: la caída de Aws S3
• Es mejor tener un plan a no tener ninguno
• No existe la bala de plata

34. Material
• https://github.com/mario21ic/infrastructure-as-code-
terraform-aws
• https://www.terraform.io/docs/
• Ebooks:
• The Terraform Book - James Turnbull
https://terraformbook.com
• Terraform up & running - Yevgeniy Brikman
http://shop.oreilly.com/product/0636920061939.do

35. Preguntas?
twitter: @mario21ic
email: mario21ic@gmail.com