Terraform Learn with Demos

In this project, we'll start using Terraform technology along with some practical Demos:

• We will learn basic concepts related to Terraform
• Try doing some hands-on demos, each Demo created in an isolated branch while working on, then merged to main.

introduction

For an Automated Infrastructure Provisioning We are going to use a common IAC tool "Terraform" which:

• Automate and manage your infrastructure.
• Open source, Declarative, and universal IAC tool which supports different cloud providers & different technologies

How does terraform work?

check Terraform Architecture:

It has two main components make up its architecture:

• Core: Find out what to do - "compare, plan and execute" by tracking 'state' and applying the required configs 'main.tf'.
• Providers: This gives you the ability to build infrastructure in an easy way.

Instructions

the following are instructions that anyone can use to deploy a terraform project, also try to follow up using *main.tf file to test the below instructions:

initialize

 terraform init

• like installing dependencies in other programming projects
• will install provider and all the required components in the script

preview terraform actions

 terraform plan

• compare the desired state with the actual current state of configs, so it will show you what is going to be applied upon the current configs.

apply config.tf file

 terraform apply         
 terraform apply -auto-approve

• for applying changes in the main.tf script and review changes.
• use the second option for going ahead without asking for confirmation

apply configuration with variables

 terraform apply -var-file terraform-dev.tfvars

• by default, when issuing apply command, it will looks for the variables file with exact file name called: terraform.tfvars, but if it was in another name like: terraform-dev.tfvars, it could not recognize it, so we should manually pass the vars file

destroy everything from .tf files

 terraform destroy

destroy a single resource

 terraform destroy -target aws_vpc.myapp-vpc

• The most efficient way if you want to delete a specific resource is to remove the configurations of that resource or comment them out in the script then issue the command > terraform apply
• So if you are working in a team, everyone should know that this resource has been deleted, but
• If you try > Terraform destroy, the config section of the destroyed resource will remain in the config.tf file, and it will cause a conflict for anyone who sees the configs for the first time, but
• you can issue the > terraform plan command to check the differnece between the configs and the current state

show resources and components from current state with "tfstate" file

 terraform state list

• tfstate file: track the current state of the provider resources, file created after first apply command
• state list: lists all the resources in the current state on aws, resources which created after last apply command

show current state of a specific resource/data

 terraform state show aws_vpc.myapp-vpc

• Instead of navigating to the aws gui to see all attributes of a particular resource you can see any attribute from the state command
• Note: There are attributes that are automatically generated by aws, so the state file has all this information, so you can get the resource id, ip address, arn etc

set avail_zone as custom tf environment variable - before apply

export TF_VAR_avail_zone="eu-west-3a"