Hands-On Practice Set 1

Let's think about this for a second

This round is about putting the Basic/Intermediate concepts you've already learned into practice — telling Resource, Variable, and Output apart, finding errors in an HCL config, and writing `terraform` commands correctly are all things you'll actually do hands-on here. No single task should take more than 5 minutes.

Let's connect this to a real scenario

Task 1: Explain the difference in roles between 'Resource', 'Variable', and 'Output' in one sentence each. Task 2: Given `resource "aws_instance" "web" { instance_type = var.instance_type }`, but the `variable "instance_type"` block is never defined anywhere in the config file, predict and write down what error would occur. Task 3: Explain why the state file matters, and give an example of the risks of local state. Task 4: If `terraform plan` shows an unexpected change (drift), which two commands would you use to investigate?

• Can explain the difference between Resource/Variable/Output
• Can spot an undefined variable reference error
• Wrote down two commands for investigating drift

Let's look at an example

# Task 2 - undefined variable
resource "aws_instance" "web" {
  instance_type = var.instance_type   # ERROR!
}
# No `variable "instance_type" { ... }` block exists anywhere.

Result: Terraform will error at `terraform plan` time with
something like: "Reference to undeclared input variable"

# Task 4 - investigating drift
terraform plan                        # shows what changed vs config
terraform state show <resource>       # inspect the current tracked state

You'll come away with the difference between Resource/Variable/Output, practice spotting an undefined variable error, and the commands used to investigate drift.