Top 25 Terraform Interview Questions and Answers in 2022


Terraform Interview Questions and Answers

With the rise of cloud computing in recent years, many new opportunities have opened up. There are a great many jobs available in cloud computing because of its sheer diversity and volume. The popularity of Terraform can be attributed to several factors. It is because all aspects of the cloud computing landscape are important to IT professionals. The popularity of tools like Terraform can be attributed to the emergence of DevOps. You will have to answer the terraform interview questions if you want to advance in your career. Top 25 frequently asked to terraform interview questions, and answers covering almost all levels have been compiled here. Terraform interview questions at the basic level are listed below.

1. What Understanding Do You Have From By Terraform In Aws?

Every cloud engineer uses Terraform as one of their IAC tools. Using human-readable configuration files, we can programmatically define Cloud and on-premise resources. Unlike most IAC tools, Terraform is not limited to a single cloud provider, one of its most notable features. Terraform allows you to run your application(s) on multiple cloud platforms simultaneously.

In case you are checking out what technologies terraform supports, here is a small list:

  • Amazon Web Service(s) (AWS)
  • Google Cloud Platforms (GCP)
  • Microsoft Azure Services
  • IBM Cloud
  • VMware vSphere
  • Server space
  • DigitalOcean
  • Oracle Cloud Infrastructure
  • Yandex. Cloud
  • OpenStack.

You will need to answer Terraform interview questions to advance your career as a DevOps Engineer, Cloud Architect, Developer, or Administrator.

2. What Are The Key Features Of Terraform?

Your Infrastructure can be managed as code and constructed as and when necessary with Terraform. Its main features are as follows:

Why Should We Hire You? 5 Best Answ...
Why Should We Hire You? 5 Best Answers
  • A console, which allows users to observe functions 
  • A great ability to translate HCL code into JSON format
  • A well-prepared and structured configuration language, which supports the interpolation feature completely
  • Module count keeps track of the number of modules applied to the Infrastructure.

3. How Will You Make An Object Of One Module Available For The Other Module At A High Level?

Resource configuration defines output variables.

  • Declare all output variables of module_A.
  • Creates file variables .tf for module B.
  • Establishes the input variable inside this file having the same name as the key defined in module_B.
  • Replicates the process for making variables available to other modules

4. What Are Some Useful Terraform Commands?

Some of the most useful Terraform commands include:

  • terraform init – It initializes the current directory
  • terraform refresh – It refreshes the state file
  • terraform output – It views Terraform outputs
  • terraform apply – It applies the Terraform code and builds stuff
  • terraform destroy – It destroys what has been built by Terraform
  • terraform graph – It creates a DOT-formatted graph
  • terraform plan – It is a dry run to see what Terraform will do

5. Are Callbacks Possible With Terraform On Azure?

Callbacks on Azure are likely to be possible when using Azure Event Hubs. Users benefit from seamless functionality provided by Terraform’s Azure supplier. Microsoft Azure Cloud Shell provides an already installed Terraform occurrence.

6. What Is Terraform Core? Tell Us Some Primary Responsibilities Of It.

Using the Go programming language, Terraform Core is statically compiled. Users can access Terraform via the compiled binary. As a primary responsibility, I am responsible for:

  • Reading and interpolation of configuration files and all modules by Infrastructure as code functionalities
  • Resource Graph Construction
  • Plugin communication through RPC
  • Plan execution
  • Management of resource state.

7. How To Store Sensitive Data In Terraform?

To communicate with the API of your cloud provider, Terraform requires credentials. On your desktop, these credentials are usually stored in plaintext. Every day, GitHub exposes thousands of API and cryptographic keys. It is therefore not recommended to store your API keys directly in Terraform code.  Anything that shouldn’t be stored in plain text, such as passwords, TLS certificates, and SSH keys, should be encrypted.

8. Can You Give Us Some Examples Where We Can Use For Sentinel Policies?

Using Sentinels in Terraform, you can implement a variety of policies. Examples include:

  • Enforcing explicit ownership of resources
  • Restricting roles the cloud provider can assume
  • Reviewing an audit trail for Terraform Cloud operations
  • Forbidding only certain resources, providers, or data sources
  • Enforcing mandatory tagging on resources 
  • Restricting how modules are properly used in Private Module Registries

9. What Are Various Levels Of Sentinel Enforcement?

There are three levels of enforcement under Sentinel – soft mandatory, advisory, and hard mandatory.

  • Advisory – It is Logged but is all allowed to pass. It is completely issued to the user when they trigger a plan that violates the policy.
  • Soft Mandatory – The policy must pass unless an override is specified. Only administrators can override.
  • Hard Mandatory – The policy must be clearly stated and passed no matter what. The same can’t be overridden until it is removed. Also, the same is the default enforcement level in Terraform.

10. What Are The Components Of Terraform Architecture?

Among the features of Terraform are:

  • Sub-graphs
  • Expression Evaluation
  • Vertex Evaluation
  • Graph Walk
  • Graph Builder
  • State Manager
  • Configuration Loader
  • CLI (Command Line interface)
  • Backend

11. What Do You Mean By Terraform Cloud?

Terraform Cloud enables teams to use Terraform together, either on-demand or in response to specific events. Unlike general-purpose continuous integration systems, it is deeply integrated with Terraform’s workflows and data. In addition, users can access state and secret data easily, update Infrastructure and govern Terraform content using detailed policy controls, and share Terraform modules using a private registry.

PS: Two people can use the same Terraform working directory to create two different infrastructure sets. Different workspaces can be used to accomplish this. These users can start two separate Terraform runs. Both users can successfully provision two different sets of Infrastructure using the same code as long as the resources do not overlap.

12. What Are The Prime Reasons To Choose Terraform For Devops?

Terraform improves the quality, consistency, and efficiency of Cloud and on-premises Infrastructure by eliminating human errors. Using Terraform, you can easily learn and use HCL, a language similar to JSON. Terraform can be used with multiple cloud platforms simultaneously, unlike other IAC tools provided by cloud providers, such as Cloud formation for AWS. Thus, multiple IAC tools do not need to be learned, and collaboration is enhanced.

PS: The “state locking” feature in Terraform is very important. This feature prevents the state file from becoming corrupt during a run and ensures no changes are made. All Terraform Backends do not support state locking. When this feature is required, you should choose the right backend.

13. What Do You Understand By Terraform Backend?

A Terraform configuration’s backend can define two main things:

  • Where operations can be easily done or performed 
  • Where the state is saved or stored. Please note that  the Terraform keeps track of all the resources created in a state file)

14. Provide Us With Terraform Configuration For Creating A Single Ec2 Instance On Aws.

AWS Terraform configuration for creating a single EC2 instance:

  • provider “aws” {
  • region = “”}
  • resource “aws_instance”
  • “example” {
  • ami = “”
  • instance_type = “”
  • tags {
  •  Name = “example”}.

15. How Can You Define Dependencies In Terraform?

Dependency management is built into Terraform. Dependencies between resources in Terraform can be implicit or explicit.

  • Terraform detects implicit dependencies automatically, as its name suggests. A “resource A” output is used in a “resource B.” As a result, Terraform automatically detects that “resource B” must be created after “resource A.”
  • When two resources are internally interdependent without sharing any outputs, explicit dependencies can be specified. Configuration blocks can be used to specify depends on parameters.

16. Explain Some Uses Of Terraform Cli And List Some Basic Cli Commands.

Terraform uses CLIs (Command-Line Interfaces) to manage Infrastructure, configure configuration files, and interact with providers.

A few basic CLI commands are listed below:

  • terraform init – It prepares your working directory for other commands
  • terraform destroy – It destroys the previously-created Infrastructure
  • terraform validate – It checks whether the configuration is valid
  • terraform apply – It creates or updates the Infrastructure
  • terraform plan – It shows changes needed by the current configuration

17. What Are The External Data Blocks In Terraform?

Scripts can be run on Terraform machines using external data blocks, just like local-exec provisioners. The difference between a provisioner and an external data block is that external data blocks can return JSON data while provisioners cannot. External data blocks should also be used as a last resort and should not be used if there is a better option.

18. What Is A Private Module Registry?

You can share Terraform modules across your organization using Terraform Cloud’s Private Module Registry. Using the registry, you can specify how members of your organization can use modules by enforcing rules or “sentinel policies.”

PS: Terraform modules are standard containers for multiple resources used for provisioning and configuring resources. A “VPC module” can, for instance, provision a standard VPC and other resources such as subnets and internet gateways for your organization. In the Public Module Registry, modules can be shared publicly, and in the Private Module Registry, they can be shared privately.

19. Is Terraform Usable For An On-Prem Infrastructure?

On-premises Infrastructure can be built with Terraform. As there are many providers where you can choose, we can decide which is best for us. It only takes an API to get started.

20. How Duplicate Are, Resource Errors Ignored During Terraform Apply?

Here are some options we can try:

  • Recreate those resources using Terraform by deleting them from the cloud provider (API)
  • To stop Terraform from managing those resources, delete them from Terraform code
  • Perform a Terraform import of the resource and remove the code that is trying to recreate it

21. Try Naming All Version Controls, Which Are Supported Perfectly By Terraform

The supported version controls include:

  • Azure DevOps Service(s)
  • Azure DevOps Server(s)
  • Bitbucket Server(s)
  • Bitbucket Cloud(s)
  • Gitlab EE and CE(s)
  • Gitlab.com(s)
  • GitHub Enterprise(s)
  • GitHub.com (OAuthorization)
  • GitHub.com(s)

22. What Are Few Built-In Provisioner(S) Widely Available For Terraform?

Here is a given list of built-in provisioners in Terraform(s):

  • Salt-masterless Provisioner(s)
  • Remote-exec Provisioner(s)
  • Puppet Provisioner(s)
  • Local-exec Provisioner(s)
  • Habitat Provisioner(s)
  • File Provisioner(s)
  • Chef Provisioner(s)

23. Which Command Completely Remove And Destroy Terraform Managed Infrastructure?

The given command is used for this issue:

terraform destroy [options] [dir]

24. Tell Us About Some Notable Terraform Application(S).

Application(s) of Terraform is pretty broad due to its facility of extending its abilities for resource manipulation. Some of the unique applications are:

  • Software demos development
  • Resource schedulers
  • Multi-cloud deployment
  • Disposable environment creations
  • Multi-tier applications development
  • Self-service clusters
  • Setup of Heroku App

25. Mention Some Other Important Terraform Commands And Explain Them

  • terraform init: It initializes remote backends; downloads providers and remote modules defined in your configuration.
  • terraform init -upgrade: It is used to upgrade the existing downloaded providers.
  • terraform plan: It generates the execution plan for the infrastructure creation or update.
  • terraform apply: It  creates or updates the Infrastructure after requesting confirmation from the user.
  • terraform apply –auto-approve: It  creates or updates the Infrastructure; the user approval stage is skipped.
  • terraform destroy: It  deletes the Infrastructure after requesting confirmation from the user.
  • terraform destroy –auto-approve: It  deletes the Infrastructure; the user approval stage is skipped.
  • terraform fmt: It  scans the current directory for configuration files and formats them according to the HCP canonical style and format.
  • terraform fmt –recursive: It  scans the current directory and the subdirectories for configuration files. It also formats them as per the HCP canonical style and format.
  • terraform show: It  provides a human-readable output from a state or plan file.

Conclusion

Terraform null resources are configurations that run as standard terraform resource blocks but do not create any resources. While it may seem like a useless resource, it can be useful to work around Terraform limitations in various situations.

Terraform is undoubtedly a vast and extensive topic that requires systematic effort to master. Explore and experiment with Terraform as much as you can (and don’t just memorize these Terraform interview questions) to have a better chance of clearing the interview. Having Simplilearn’s Cloud Computing PGP in collaboration with Caltech CTME, you can start your successful cloud journey today!

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