Terraform.tfvars file - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign a value to the variable 'region' in a Terraform.tfvars file.

Terraform

region = "[1]"

Drag options to blanks, or click blank then click option'

Aus-west-2

Btrue

C123

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using boolean or numeric values instead of a string for region.

Forgetting to put quotes around the region value.

The Terraform.tfvars file assigns values to variables. Here, region is set to a string value representing the cloud region.

2fill in blank

medium

Complete the code to assign a list of availability zones in Terraform.tfvars format.

Terraform

availability_zones = [1]

Drag options to blanks, or click blank then click option'

A{us-west-2a, us-west-2b}

B"us-west-2a, us-west-2b"

Cus-west-2a, us-west-2b

D["us-west-2a", "us-west-2b"]

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces instead of square brackets for lists.

Not quoting the strings inside the list.

Lists in Terraform.tfvars are written with square brackets and quoted strings for each item.

3fill in blank

hard

Fix the error in the Terraform.tfvars assignment for the variable 'enable_logging'.

Terraform

enable_logging = [1]

Drag options to blanks, or click blank then click option'

Atrue

B'true'

CTrue

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around boolean values.

Capitalizing boolean values.

Boolean values in Terraform.tfvars are written without quotes and in lowercase.

4fill in blank

hard

Fill both blanks to assign a map variable in Terraform.tfvars format.

Terraform

tags = { [1] = "Production", [2] = "WebApp" }

Drag options to blanks, or click blank then click option'

AEnvironment

BName

CVersion

DOwner

Attempts:

3 left

💡 Hint

Common Mistakes

Quoting keys in maps.

Using incorrect key names.

Maps in Terraform.tfvars use key-value pairs inside curly braces. Keys are unquoted strings and values are quoted strings.

5fill in blank

hard

Fill all three blanks to assign variables of different types in Terraform.tfvars.

Terraform

instance_count = [1]
instance_type = "[2]"
enabled = [3]

Drag options to blanks, or click blank then click option'

A3

Bt3.micro

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Quoting numbers or booleans.

Using uppercase for boolean values.

Numbers are written without quotes, strings with quotes, and booleans without quotes in Terraform.tfvars.

Practice

1. What is the main purpose of the terraform.tfvars file in a Terraform project?

easy

A. To store Terraform state files

B. To define the Terraform provider configuration

C. To write the main infrastructure resources

D. To store values for variables separately from the main Terraform code

Solution

1. Step 1: Understand the role of terraform.tfvars

   This file is used to provide values for variables declared in Terraform configuration files, keeping values separate from code.

2. Step 2: Differentiate from other files

   Provider configuration and resource definitions are in .tf files, and state files are managed separately, not in terraform.tfvars.

3. Final Answer:

   To store values for variables separately from the main Terraform code -> Option D

4. Quick Check:

   Variable values stored separately = D [OK]

Hint: Remember: tfvars holds variable values, not code or state [OK]

Common Mistakes:

• Confusing tfvars with provider or resource files
• Thinking tfvars stores state files
• Assuming tfvars contains resource definitions

2. Which of the following is the correct syntax to assign a list of strings in a terraform.tfvars file?

easy

A. my_list = {"apple", "banana", "cherry"}

B. my_list = ("apple", "banana", "cherry")

C. my_list = ["apple", "banana", "cherry"]

D. my_list = "apple", "banana", "cherry"

Solution

1. Step 1: Identify list syntax in tfvars

   Terraform uses square brackets [] to define lists in tfvars files.

2. Step 2: Check each option

   my_list = ["apple", "banana", "cherry"] uses square brackets with quoted strings, which is correct. Options B and C use parentheses or curly braces, which are invalid for lists. my_list = "apple", "banana", "cherry" is missing brackets.

3. Final Answer:

   my_list = ["apple", "banana", "cherry"] -> Option C

4. Quick Check:

   Lists use square brackets [] = A [OK]

Hint: Lists always use square brackets [] in tfvars [OK]

Common Mistakes:

• Using parentheses or curly braces instead of square brackets
• Forgetting quotes around string items
• Omitting brackets entirely

3. Given the following terraform.tfvars content:

region = "us-west-2"
instance_count = 3
enable_backup = true
allowed_ips = ["10.0.0.1", "10.0.0.2"]

What is the value and type of enable_backup when accessed in Terraform?

medium

A. String "true"

B. Boolean true

C. Number 1

D. List with one element "true"

Solution

1. Step 1: Identify the value type in tfvars

   The value enable_backup = true is a boolean literal, not a string or number.

2. Step 2: Understand Terraform variable typing

   Terraform reads true as a boolean true, not as a string or number.

3. Final Answer:

   Boolean true -> Option B

4. Quick Check:

   Boolean literals stay boolean = B [OK]

Hint: True/false without quotes are booleans in tfvars [OK]

Common Mistakes:

• Treating true as a string by adding quotes
• Assuming true converts to number 1
• Confusing boolean with list type

4. You wrote this in your terraform.tfvars file:

max_instances = 5
allowed_ports = [80, 443, 22

When running Terraform, you get a syntax error. What is the most likely cause?

medium

A. Missing closing bracket for the list

B. Using numbers instead of strings in the list

C. Variable names cannot have underscores

D. The equals sign should be a colon

Solution

1. Step 1: Check list syntax carefully

   The list allowed_ports is opened with [ but the snippet ends after 22 with no closing ].

2. Step 2: Identify syntax error

   The list lacks a closing bracket, causing the syntax error. Other options are invalid: underscores are allowed, numbers are fine in lists, and = is correct syntax.

3. Final Answer:

   Missing closing bracket for the list -> Option A

4. Quick Check:

   Lists must have matching brackets = C [OK]

Hint: Always count opening and closing brackets in lists [OK]

Common Mistakes:

• Forgetting to close lists with a bracket
• Thinking numbers must be strings
• Using colons instead of equals

5. You want to use a map variable in your Terraform configuration to assign different instance types per environment. Which terraform.tfvars content correctly assigns instance types for "dev" and "prod" environments?

hard

A. instance_types = { dev = "t2.micro", prod = "t2.large" }

B. instance_types = ["dev" = "t2.micro", "prod" = "t2.large"]

C. instance_types = (dev: "t2.micro", prod: "t2.large")

D. instance_types = { "dev", "t2.micro", "prod", "t2.large" }

Solution

1. Step 1: Understand map syntax in tfvars

   Maps use curly braces {} with key = value pairs, keys and values can be strings.

2. Step 2: Evaluate each option

   instance_types = { dev = "t2.micro", prod = "t2.large" } correctly uses curly braces with keys and values separated by =. instance_types = ["dev" = "t2.micro", "prod" = "t2.large"] uses square brackets and equals inside, which is invalid. instance_types = (dev: "t2.micro", prod: "t2.large") uses parentheses and colons, invalid syntax. instance_types = { "dev", "t2.micro", "prod", "t2.large" } uses curly braces but with commas separating keys and values without equals, invalid.

3. Final Answer:

   instance_types = { dev = "t2.micro", prod = "t2.large" } -> Option A

4. Quick Check:

   Maps use curly braces with key = value pairs = A [OK]

Hint: Maps use curly braces with key = value pairs in tfvars [OK]

Common Mistakes:

• Using square brackets for maps
• Using colons instead of equals
• Separating keys and values with commas only