Terraform variables

Following documentation about language https://developer.hashicorp.com/terraform/language and variables types and interpolation

Also this https://developer.hashicorp.com/terraform/tutorials/configuration-language/variables

Steps

terraform init
terraform fmt
terraform validate
terraform plan

Key points

using different common variables types: string, number, bool, list, map
default values usage or not
tfvars file usage https://developer.hashicorp.com/terraform/tutorials/configuration-language/variables#assign-values-with-a-file
interpolation: https://developer.hashicorp.com/terraform/tutorials/configuration-language/variables#interpolate-variables-in-strings
validation: https://developer.hashicorp.com/terraform/tutorials/configuration-language/variables#validate-variables
sensitive variables using tfvars or env variables (or from inputs from the cli): https://developer.hashicorp.com/terraform/tutorials/configuration-language/sensitive-variables