Terraform uses HCL (HashiCorp Configuration Language) which is a domain-specific language (DSL) and a declarative language used to define and configure infrastructure resources
- Resource is an object that’s a type of block (ex: resource, provider, output, etc..) which Terraform manages which describes one or more infrastructure objects
- Resource Name can be any name
- Consider reading this article to have a big picture about resources and their behaviors, and check the docs by chance and take note on their meta-arguments
Check Terraform’s docs about HCL to know more
When including a new provider, be sure to re-run terraform init
terraform.tfstate is the state file, which contains the complete record of the infrastructure created by Terraform and works as the single source of truth
- Its not recommended to use a local state file if there’s a team working on the infrastructure, if there are two members trying to execute the same Terraform one will get locked out
- Its best to put the state file in a remote state backend (say S3 Bucket) to avoid conflicts, avoid putting the state file in a version control system as it can risk with two team members working simultaneously which can lead to data loss and conflicts
- When working as a team, the Terraform config files are stored in a repository while the state files are stored in a remote shared storage
- Never manually edit the state file
Check this guide to create a remote state setup for the backend
- Automatically locks, loads and uploads the state file
- Remote state backend shared storage solutions examples: Terraform Cloud, S3 Bucket, Hashicorp Consul, etc..
- If you want to use a data source from another remote state consider using
terraform_remote_statedata source to retrieve the root module output values from some other Terraform configuration
There can be constraints in provider versions, so make sure you’re using a consistent version. To be sure of the version you can do the following example which finds a version between 1.2.0 and 2.0.0 except for 1.4.0
terraform {
required_providers {
local = {
source: "hashicorp/local"
version = "> 1.2.0, < 2.0.0, != 1.4.0"
}
}
}
You can group or isolate mechanism using alias (namespace) for resources
// provider.tf
provider "aws" {
region = "ca-central-1"
alias = "central"
}
// main.tf
resource "aws_key_pair" "alpha" {
key_name = "alpha"
public_key = "..."
provider = aws.central // <provider_name>.<alias_name>
}
A list (or tuple) is a sequence of values which can be of any type mixed together
A set is a collection of unique values
You can change log level when doing terraform plan or apply using export TF_LOG=TRACE
- Other levels:
info,warning,error,debug,trace - If you want the logs to be stored in a specific path, use
export TF_LOG_PATH=/tmp/terraform.log
Terraform Cloud is a platform that helps with managing your Terraform code and collaboration between developers which simplifies workflow and improves security
