Availability zones data source in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to fetch availability zones in the current region.

Terraform

data "aws_availability_zones" "available" {
  state = "[1]"
}

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

Aenabled

Bactive

Cavailable

Dpresent

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect state values like 'active' or 'enabled' which are invalid.

The state attribute must be set to available to fetch zones that are currently available.

2fill in blank

medium

Complete the code to output the list of availability zone names.

Terraform

output "az_names" {
  value = data.aws_availability_zones.available.[1]
}

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

Anames

Bids

Czone_ids

Dzones

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'zones' or 'ids' which are not valid attributes for names.

The names attribute returns the list of availability zone names.

3fill in blank

hard

Fix the error in the data source block to correctly filter zones by state.

Terraform

data "aws_availability_zones" "filtered" {
  state = "[1]"
}

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

Aenabled

Bavailable

Cpresent

Dactive

Attempts:

3 left

💡 Hint

Common Mistakes

Using invalid state values like 'enabled' or 'active' causes errors.

The correct state filter value is available to get usable availability zones.

4fill in blank

hard

Fill both blanks to create a data source that fetches only available zones and outputs their count.

Terraform

data "aws_availability_zones" "example" {
  state = "[1]"
}

output "az_count" {
  value = length(data.aws_availability_zones.example.[2])
}

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

Aavailable

Bnames

Czones

Dactive

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'active' as state or 'zones' as attribute causes errors.

Set state to available to get usable zones, and use names to count them.

5fill in blank

hard

Fill all three blanks to create a data source fetching available zones, output their names, and output their count.

Terraform

data "aws_availability_zones" "all" {
  state = "[1]"
}

output "all_az_names" {
  value = data.aws_availability_zones.all.[2]
}

output "all_az_count" {
  value = length(data.aws_availability_zones.all.[3])
}

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

Aavailable

Bnames

Dactive

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'active' as state or wrong attributes for outputs.

Use available for state, and names for both outputs to list and count zones.

Practice

1. What is the main purpose of the availability_zones data source in Terraform?

easy

A. To delete unused availability zones

B. To create new availability zones in a region

C. To list all availability zones in a specified cloud region

D. To monitor the health status of availability zones

Solution

1. Step 1: Understand the data source role

   The availability_zones data source is used to fetch information, not to create or delete resources.

2. Step 2: Identify what information it provides

   It returns a list of availability zones available in the specified region, helping to distribute resources.

3. Final Answer:

   To list all availability zones in a specified cloud region -> Option C

4. Quick Check:

   Data source lists zones [OK]

Hint: Data sources fetch info; they don't create or delete [OK]

Common Mistakes:

• Thinking data source creates zones
• Confusing data source with resource
• Assuming it monitors zone health

2. Which of the following is the correct syntax to declare the AWS availability zones data source in Terraform?

easy

A. module "aws_availability_zones" {}

B. resource "aws_availability_zones" "example" {}

C. provider "aws_availability_zones" {}

D. data "aws_availability_zones" "example" {}

Solution

1. Step 1: Identify the correct Terraform block type for data sources

   Data sources use the data block, not resource, provider, or module.

2. Step 2: Check the correct resource type name

   The AWS availability zones data source is named aws_availability_zones, so the syntax is data "aws_availability_zones" "example" {}.

3. Final Answer:

   data "aws_availability_zones" "example" {} -> Option D

4. Quick Check:

   Data source syntax = data + resource type [OK]

Hint: Data sources start with 'data' keyword, not 'resource' [OK]

Common Mistakes:

• Using resource instead of data
• Using provider or module blocks incorrectly
• Misspelling the data source name

3. Given this Terraform snippet, what will output.zones contain?

data "aws_availability_zones" "available" {}

output "zones" {
  value = data.aws_availability_zones.available.names
}

medium

A. A list of availability zone names in the current AWS region

B. An error because names is not a valid attribute

C. A count of availability zones as a number

D. An empty list because no zones are specified

Solution

1. Step 1: Understand the data source attributes

   The aws_availability_zones data source provides an attribute names which is a list of zone names in the region.

2. Step 2: Check the output value

   The output references data.aws_availability_zones.available.names, so it will output the list of zone names.

3. Final Answer:

   A list of availability zone names in the current AWS region -> Option A

4. Quick Check:

   Output uses .names attribute = list of zones [OK]

Hint: Use .names to get zone names list from data source [OK]

Common Mistakes:

• Assuming .names attribute does not exist
• Expecting a count instead of list
• Thinking output is empty without explicit zones

4. You wrote this Terraform code but get an error: data.aws_availability_zones.invalid not found. What is the problem?

data "aws_availability_zones" "valid" {}

output "zones" {
  value = data.aws_availability_zones.invalid.names
}

medium

A. You must specify zones explicitly in the data source

B. The data source name used in output does not match the declared name

C. The names attribute does not exist

D. Terraform does not support availability zones data source

Solution

1. Step 1: Check the data source declaration

   The data source is declared as aws_availability_zones.valid.

2. Step 2: Check the output reference

   The output references data.aws_availability_zones.invalid, which does not exist.

3. Step 3: Identify the mismatch

   The error occurs because the output references a non-existent data source name.

4. Final Answer:

   The data source name used in output does not match the declared name -> Option B

5. Quick Check:

   Name mismatch causes not found error [OK]

Hint: Match data source names exactly in output references [OK]

Common Mistakes:

• Using wrong data source name in output
• Assuming .names attribute is missing
• Thinking zones must be specified manually

5. You want to deploy resources evenly across exactly 2 availability zones using Terraform's aws_availability_zones data source. Which code snippet correctly limits the zones to 2?

hard

A. data "aws_availability_zones" "example" {
state = "available"
filter {
name = "zone-name"
values = ["us-east-1a", "us-east-1b"]
}
}

B. data "aws_availability_zones" "example" {
state = "available"
all_availability_zones = false
filter {
name = "zone-name"
values = ["us-east-1a", "us-east-1b"]
}
}

C. data "aws_availability_zones" "example" {
state = "available"
all_availability_zones = true
filter {
name = "zone-name"
values = ["us-east-1a", "us-east-1b"]
}
}

D. data "aws_availability_zones" "example" {
state = "available"
zones = ["us-east-1a", "us-east-1b"]
}

Solution

1. Step 1: Understand filtering in aws_availability_zones

   The data source returns only AZs matching the filter criteria when a filter block is provided with name = "zone-name" and desired values.

2. Step 2: Identify valid configuration

   Use state = "available" and filter { name = "zone-name" values = ["us-east-1a", "us-east-1b"] } to limit exactly to those two zones.

3. Step 3: Invalid alternatives fail

   Using all_availability_zones or zones introduces non-existent arguments, causing Terraform validation errors.

4. Final Answer:

   data "aws_availability_zones" "example" { state = "available" filter { name = "zone-name" values = ["us-east-1a", "us-east-1b"] } } -> Option A

5. Quick Check:

   zone-name filter limits to specified AZs [OK]

Hint: Use zone-name filter to select specific AZs [OK]

Common Mistakes:

• Using invalid attributes like all_availability_zones
• Using unsupported 'zones' attribute
• Overcomplicating with non-existent parameters