Querying existing resources in Terraform - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the data block in Terraform?

The data block is used to query and read information about existing resources that are not managed by the current Terraform configuration.

beginner

How do you reference an existing AWS VPC by its ID in Terraform?

You use a data block like this:<br>

data "aws_vpc" "example" {
  id = "vpc-12345678"
}

<br>This lets you access its attributes in your configuration.

intermediate

Why should you use data sources instead of hardcoding resource attributes?

Using data sources keeps your configuration flexible and up-to-date by dynamically fetching current resource details instead of relying on fixed values that may change.

intermediate

What happens if the queried resource does not exist when using a Terraform data source?

Terraform will return an error during plan or apply because it cannot find the resource to read its attributes.

beginner

Can you modify existing resources using Terraform data sources?

No, data sources only read information. To modify resources, you must use resource blocks managed by Terraform.

What Terraform block is used to query existing resources?

A output

B resource

C data

D variable

The data block is specifically designed to query existing resources.

Which of the following is TRUE about Terraform data sources?

A They read information from existing resources.

B They store variables.

C They delete resources.

D They can create new resources.

Data sources only read information from existing resources; they do not create or delete resources.

If a data source references a non-existent resource, what will happen?

A Terraform will create the resource automatically.

B Terraform will ignore the missing resource.

C Terraform will skip the data source silently.

D Terraform will return an error during plan or apply.

Terraform requires the resource to exist to read its data; otherwise, it errors out.

How do you access an attribute from a data source in Terraform?

A Using <code>data.<resource_type>.<name>.<attribute></code>

B Using <code>resource.<name>.<attribute></code>

C Using <code>var.<attribute></code>

D Using <code>output.<attribute></code>

Attributes from data sources are accessed with the syntax data....

Why is it better to use data sources instead of hardcoding resource IDs?

A Data sources are faster to deploy.

B Data sources keep configurations flexible and accurate.

C Data sources automatically update resource attributes.

D Data sources create new resources.

Using data sources helps keep your configuration flexible and accurate by fetching current resource details.

Explain how Terraform data sources help you work with existing cloud resources.

Think about how you can read info without managing the resource.

Describe the difference between Terraform resource blocks and data blocks.

One manages, the other queries.