Output values after apply in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define an output that shows the instance ID.

Terraform

output "instance_id" {
  value = [1]
}

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

Aaws_instance.example.name

Baws_instance.example.id

Caws_instance.example.type

Daws_instance.example.region

Attempts:

3 left

💡 Hint

Common Mistakes

Using .name or .type instead of .id

Forgetting to reference the resource name

The output value should be the instance ID property to show the unique identifier after apply.

2fill in blank

medium

Complete the output block to display the public IP of the instance.

Terraform

output "public_ip" {
  value = [1]
}

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

Aaws_instance.web.public_dns

Baws_instance.web.private_ip

Caws_instance.web.public_ip

Daws_instance.web.id

Attempts:

3 left

💡 Hint

Common Mistakes

Using .private_ip instead of .public_ip

Using .id or .public_dns instead

The public IP address is accessed with .public_ip on the instance resource.

3fill in blank

hard

Fix the error in the output block to correctly show the subnet ID.

Terraform

output "subnet_id" {
  value = [1]
}

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

Aaws_subnet.main.id

Baws_subnet.main.name

Caws_subnet.main.subnet_id

Daws_subnet.main.cidr_block

Attempts:

3 left

💡 Hint

Common Mistakes

Using .subnet_id which does not exist

Using .name or .cidr_block instead of .id

The correct attribute for subnet ID is .id, not .subnet_id.

4fill in blank

hard

Fill both blanks to output the instance's private IP and availability zone.

Terraform

output "instance_info" {
  value = {
    private_ip = [1]
    az         = [2]
  }
}

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

Aaws_instance.app.private_ip

Baws_instance.app.public_ip

Caws_instance.app.availability_zone

Daws_instance.app.id

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing public_ip with private_ip

Using .id instead of availability_zone

Private IP is accessed with .private_ip and availability zone with .availability_zone on the instance resource.

5fill in blank

hard

Fill all three blanks to output the bucket name, region, and ARN.

Terraform

output "bucket_details" {
  value = {
    name   = [1]
    region = [2]
    arn    = [3]
  }
}

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

Aaws_s3_bucket.mybucket.bucket

Baws_s3_bucket.mybucket.region

Caws_s3_bucket.mybucket.arn

Daws_s3_bucket.mybucket.id

Attempts:

3 left

💡 Hint

Common Mistakes

Using .id instead of .bucket for the name

Confusing region with ARN

The bucket name is accessed with .bucket, region with .region, and ARN with .arn attributes.

Practice

1. What is the main purpose of output values in a Terraform configuration?

easy

A. To create new cloud resources

B. To display important information after Terraform applies changes

C. To define variables used inside Terraform modules

D. To store Terraform state files remotely

Solution

1. Step 1: Understand the role of output values

   Output values are used to show key information after Terraform finishes applying infrastructure changes.

2. Step 2: Differentiate outputs from other Terraform features

   Variables define inputs, resources create infrastructure, and state files store deployment state. Outputs specifically display results.

3. Final Answer:

   To display important information after Terraform applies changes -> Option B

4. Quick Check:

   Outputs = display info after apply [OK]

Hint: Outputs show info after apply, not inputs or resources [OK]

Common Mistakes:

• Confusing outputs with variables
• Thinking outputs create resources
• Mixing outputs with state storage

2. Which of the following is the correct syntax to define an output named instance_ip in Terraform?

easy

A. output "instance_ip" { value = aws_instance.example.private_ip }

B. output instance_ip = aws_instance.example.private_ip

C. output "instance_ip" = aws_instance.example.private_ip

D. output { instance_ip = aws_instance.example.private_ip }

Solution

1. Step 1: Recall Terraform output block syntax

   Outputs use the block syntax: output "name" { value = ... }.

2. Step 2: Match syntax to options

   output "instance_ip" { value = aws_instance.example.private_ip } matches the correct block syntax with quotes and value assignment.

3. Final Answer:

   output "instance_ip" { value = aws_instance.example.private_ip } -> Option A

4. Quick Check:

   Output block = output "name" { value = ... } [OK]

Hint: Outputs need block syntax with quotes and value key [OK]

Common Mistakes:

• Missing quotes around output name
• Using equals sign outside block
• Incorrect block structure

3. Given this Terraform output block:

output "bucket_name" {
  value = aws_s3_bucket.my_bucket.id
}

What will Terraform display after terraform apply if the bucket ID is my-bucket-123?

medium

A. "aws_s3_bucket.my_bucket.id"

B. "my-bucket-123"

C. bucket_name = "my-bucket-123"

D. No output will be shown

Solution

1. Step 1: Understand output display format

   Terraform outputs show the output name followed by an equals sign and the value.

2. Step 2: Apply the known value

   The value aws_s3_bucket.my_bucket.id is "my-bucket-123", so output shows: bucket_name = "my-bucket-123".

3. Final Answer:

   bucket_name = "my-bucket-123" -> Option C

4. Quick Check:

   Output format = name = value [OK]

Hint: Outputs show name = value after apply [OK]

Common Mistakes:

• Expecting only the value without name
• Confusing resource attribute with output text
• Thinking outputs are hidden by default

4. You wrote this output block:

output "db_password" {
  value = var.db_password
  sensitive = true
}

After terraform apply, you still see the password printed in the console. What is the likely cause?

medium

A. You ran terraform output -raw db_password after apply

B. You must set sensitive = false to hide output

C. Terraform does not support sensitive outputs

D. The output block syntax is invalid

Solution

1. Step 1: Understand sensitive output behavior

   Sensitive outputs hide values in the terraform apply console and standard terraform output. However, terraform output -raw <name> bypasses this and shows the value.

2. Step 2: Identify cause of exposure

   The likely cause is running terraform output -raw db_password, which reveals sensitive values.

3. Final Answer:

   You ran terraform output -raw db_password after apply -> Option A

4. Quick Check:

   Sensitive hides output unless -raw [OK]

Hint: Sensitive hides output unless -raw used [OK]

Common Mistakes:

• Thinking sensitive = false hides output
• Believing Terraform can't mark outputs sensitive
• Assuming syntax error causes exposure

5. You want to output a list of instance IPs from multiple AWS instances created with a count. Which output block correctly returns all private IPs after apply?

resource "aws_instance" "web" {
  count = 3
  private_ip = "10.0.0.${count.index + 1}"
}

output "instance_ips" {
  value = ???
}

hard

A. aws_instance.web[0].private_ip

B. aws_instance.web.*

C. aws_instance.web.private_ip

D. [for i in aws_instance.web : i.private_ip]

Solution

1. Step 1: Understand how to access multiple instances' attributes

   When using count, aws_instance.web is a list of resources. To get all private_ip values, use a for expression to extract each.

2. Step 2: Evaluate options for correct syntax

   [for i in aws_instance.web : i.private_ip] uses a for expression to collect private_ip from each instance, which is valid and recommended.

3. Final Answer:

   [for i in aws_instance.web : i.private_ip] -> Option D

4. Quick Check:

   Use for expression to list attributes from count resources [OK]

Hint: Use for expressions to output lists from multiple resources [OK]

Common Mistakes:

• Using wildcard (*) syntax without the attribute
• Accessing single instance only
• Trying to output resource without indexing