Terraform.tfvars file - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Configuration

intermediate

Identify the correct value of a variable from a Terraform.tfvars file

Given the following Terraform.tfvars content, what is the value of the variable instance_count after Terraform applies the configuration?

Terraform

instance_count = 3
region = "us-west-2"
instance_type = "t2.micro"

A 3

B us-west-2

C t2.micro

D null

💡 Hint

Look for the variable name and its assigned value in the tfvars content.

The variable instance_count is assigned the value 3 in the Terraform.tfvars file, so Terraform uses this value during deployment.

❓ service_behavior

intermediate

Effect of missing variable in Terraform.tfvars file

If a variable db_password is declared in Terraform but not set in the Terraform.tfvars file or elsewhere, what will happen when you run terraform apply?

Terraform

variable "db_password" {
  type = string
  description = "The database password"
}

A Terraform will automatically generate a random password

B Terraform will prompt for the value during apply

C Terraform will use an empty string as the value

D Terraform will fail with a syntax error

💡 Hint

Think about how Terraform handles variables without default values and no input.

Terraform prompts the user to enter a value for variables that have no default and are not set in any input files like tfvars.

❓ Architecture

advanced

Choosing the right Terraform.tfvars file for multiple environments

You have two Terraform.tfvars files: dev.tfvars and prod.tfvars. How do you apply the Terraform configuration for the production environment using the correct tfvars file?

A terraform apply -var-file=prod.tfvars

B terraform apply -var prod.tfvars

C terraform apply --tfvars=prod.tfvars

D terraform apply -config=prod.tfvars

💡 Hint

Check the Terraform CLI option to specify a variable file.

The correct CLI option to specify a variable file is -var-file. This tells Terraform to load variables from the given file.

❓ security

advanced

Best practice for sensitive data in Terraform.tfvars files

Which practice is best to keep sensitive data like passwords secure when using Terraform.tfvars files?

A Encrypt the Terraform.tfvars file and commit the encrypted file to version control

B Store sensitive values in Terraform.tfvars and commit the file to version control

C Use environment variables or secret management tools instead of storing sensitive data in Terraform.tfvars

D Write sensitive data directly in Terraform configuration files

💡 Hint

Think about how to avoid exposing secrets in code repositories.

Storing sensitive data in environment variables or secret managers avoids exposing secrets in files that might be committed to version control.

🧠 Conceptual

expert

Understanding variable precedence with Terraform.tfvars

Given a variable region defined with a default in Terraform, set to "us-east-1", and also set in terraform.tfvars as "us-west-2", and finally set via CLI as -var='region=eu-central-1', what value will Terraform use for region?

Terraform

variable "region" {
  type = string
  default = "us-east-1"
}

A us-east-1

B us-west-2

C Terraform will raise an error due to conflicting values

D eu-central-1

💡 Hint

Remember the order of precedence for variable values in Terraform.

Terraform uses CLI -var values first, then tfvars files, then defaults. So CLI value eu-central-1 overrides others.