# Terraform Associate (004) – Exam Cheat Sheet This cheat sheet is based on my notes from online courses, Hashicorp documentation, and **missing & updated concepts for the Terraform Associate 004 exam** after completing the exam. It is optimized for **quick revision before the exam**. --- ## 1\. Terraform Core Workflow ### Core Commands ```bash terraform init # Initialize providers & backend terraform plan # Preview execution plan terraform apply # Apply changes terraform destroy # Destroy resources ``` ### Typical Workflow 1. Write `.tf` files 2. `terraform init` 3. `terraform plan` 4. `terraform apply` --- ## 2\. Terraform Configuration Basics ### Blocks ```bash resource "aws_instance" "example" {} ``` | Block | Purpose | | --- | --- | | provider | Define cloud provider | | resource | Infrastructure object | | variable | Input variable | | output | Export values | | data | Read external data | | module | Reusable configuration | | terraform | Backend & version config | | action | Invoke provider-defined action | | check | Validate your infrastructure | | ephermal | define temporary resources | | import | import existing infrastructure | | locals | define values and reuse | | moved | change the address of a resource | | removed | remove from state without changing infra | --- ## 3\. Providers ### Provider Types * Official * Partner * Community ### Provider Configuration ```apache provider "aws" { region = "us-east-1" } ``` ### Version Constraints ```apache terraform { required_providers { aws = { source = "hashicorp/aws" version = "~> 5.0" } } } ``` Version rules: * `>= 1.2.0` * `<= 2.0.0` * `~> 1.2` → >=1.2,<2.0 * `!= 1.4.0` --- ## 4\. Variables ### Declare Variables ```apache variable "filename" { type = string description = "File name" default = "/tmp/file.txt" } ``` ### Types * string * number * bool * list(type) * map(type) * object({}) * tuple(\[\]) ### Variable Precedence (High → Low) 1. CLI `var` 2. `.tfvars` or `var-file` 3. Environment (`TF_VAR_name`) 4. Default --- ## 5\. Resource Attributes & References ```apache ${resource_type.resource_name.attribute} ``` Example: ```apache aws_instance.web.public_ip ``` --- ## 6\. Dependencies ### Implicit ```apache instance_id = aws_instance.web.id ``` ### Explicit ```apache depends_on = [aws_instance.web] ``` --- ## 7\. Output Values ```bash output "public_ip" { value = aws_instance.web.public_ip } ``` Commands: ```bash terraform output terraform output public_ip ``` --- ## 8\. Terraform State ### Purpose * Maps config → real infrastructure * Tracks metadata & dependencies ### State Storage * Local (default) * Remote (recommended): * S3 * Terraform Cloud * GCS * Consul Remote state locking is available, depending on whether the backend supports ### Remote Backend (S3 Example) ```apache terraform { backend "s3" { bucket = "tf-state-bucket" key = "prod/terraform.tfstate" region = "us-east-1" dynamodb_table = "terraform-locks" } } ``` --- ## 9\. Terraform State Commands ```bash terraform state list terraform state show terraform state mv terraform state rm terraform state pull ``` --- ## 10\. Lifecycle Rules ```apache lifecycle { create_before_destroy = true prevent_destroy = true ignore_changes = [tags] } ``` --- ## 11\. Meta-Arguments [https://developer.hashicorp.com/terraform/language/meta-arguments](https://developer.hashicorp.com/terraform/language/meta-arguments) | Argument | Description | | --- | --- | | depends\_on | Explicit dependency | | count | Create multiple resources | | for\_each | Iterate over map/set | | lifecycle | Control resource behavior | | provider | specifies which provider to use | | providers | specify an alternate provider specification | ### count vs for\_each * `count` → indexed list * `for_each` → map or set --- ## 12\. Data Sources Used to **read existing resources**: ```bash data "aws_ami" "amazon_linux" { most_recent = true } ``` --- ## 13\. Provisioners (Use Sparingly) ### Local Exec ```bash provisioner "local-exec" { command = "echo Hello" } ``` ### Remote Exec Requires SSH access. ⚠️ **Not recommended for production** --- ## 14\. Terraform Import ```bash terraform import aws_instance.web i-123456 ``` ⚠️ Does NOT generate `.tf` code. Only updates the state file. --- ## 15\. Terraform Workspaces ```bash terraform workspace new dev terraform workspace list terraform workspace select dev ``` Each workspace has **separate state**. --- ## 16\. Terraform Functions (Important) [https://developer.hashicorp.com/terraform/language/functions](https://developer.hashicorp.com/terraform/language/functions) ### Numeric * `max()` * `min()` * `ceil()` * `floor()` ### String * `lower()` * `upper()` * `split()` * `join()` * `substr()` ### Collection * `length()` * `contains()` * `element()` * `lookup()` --- ## 17\. Terraform Console ```bash terraform console ``` Used for testing expressions. --- ## 18\. Debugging ```bash export TF_LOG=TRACE export TF_LOG_PATH=/tmp/terraform.log ``` Levels: * TRACE * DEBUG * INFO * WARN * ERROR --- ## 19\. Terraform Modules ```apache module "vpc" { source = "terraform-aws-modules/vpc/aws" version = "5.0.0" } ``` Commands: ```bash terraform get ``` --- ## 20\. Security Best Practices * Never commit `terraform.tfstate` * Use `.gitignore` * Encrypt remote state * Use least privilege --- ## 21\. Quick Commands Summary ```bash terraform init terraform plan terraform apply terraform destroy terraform fmt terraform validate terraform providers terraform output terraform graph terraform workspace list ``` ## 22\. HCP Terraform The HashiCorp Cloud Platform — [https://developer.hashicorp.com/terraform/cloud-docs](https://developer.hashicorp.com/terraform/cloud-docs) In my experience in this exam, you have to know what they are; there is no need to dig deep, so briefly review these topics, and let me know your experience: * Users * Teams * Organizations * Permissions * Stacks & Workspaces * Integration with VCS (Version Control Systems) * Private registry * Automatic health checks * Run triggers