Terraform Basics - Tutorials

Terraform Workflow#

Write the terraform configuration =====> Plan the infrastructure =====> deploy the infrastructure

Terraform Initialization#

terraform init initializes the working directory for terraform

Terraform Key Concepts#

terraform plan After initializtion, reads the terraform code and shows the plan of execution / deployment. In this phase, the authentication of credentials takes place
terraform apply Deploys the infrastructure and statements in code
terraform destory Destorys all of the deployed infrastructure and removes the resources
WARNING
Non-reversible command. Proceed with caution

Stages of Terrform#

Write IaC =====> terraform init =====> terraform plan =====> terraform apply

Terraform Providers#

providers are cloud vendors like aws, azure, google cloud etc. to which terrraform interacts to create resources
terraform providers should always be versioned

Creating a machine using AWS as a provider#

Project Files and What they do#

project files

main.tf contains the resource defining code and provider defining code.

    terraform {
    required_providers {
      aws = {
        source  = "hashicorp/aws"
        version = "~> 5.0"
      }
    }
  }
  resource "aws_instance" "instance_tf" {
    ami           = "ami-05803413c51f242b7"
    instance_type = "t2.micro"
  }

provider.tf.example contains the information needed by the provides, sometimes confidential secrets and passwords. Never share the providers.tf file if they contain your secrets. The .example has to be removed to use the file. Terraform will automatically use the provider.tf file to get the provider configuration files.

provider "aws" {
  access_key = "your aws access key"
  secret_key = "your aws secret key"
  region     = "your aws region"
}

Currently, these are the only files you need to get an instance in AWS running.

Passing the credentials as environment variables#

from your terminal, export your environmental variables as export AWS_ACCESS_KEY = "your key"
to check you can use: env | grep -i aws which shows all the environmental variables starting with aws.
to pass the environmental variables, no need to specify them when using terraform plan or terraform apply. Terraform will automatically read the variables from your environment and access them.

Terraform State#

important for resource tracking
is a way that terraform read to identify what has been deployed
also seen as a database for terraform
named as terraform.tfstate
usually stored in same working directory, can also be stored remotely

CAUTION
Never loose terraform state file

Github Repo for the practice files#

Find the attached github repo for the files if you need to take a look. Also, some files will be missing as they may contain secrets. Figure them out yourself

asup20cs

terraform-practice

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