Terraform Interview Questions

Terraform is a popular IT infrastructure automation tool. According to Statista, DevOps engineers mostly choose Terraform for infrastructure provisioning over other DevOps tools. The critical feature of Terraform is that it enables you to build, modify, and deploy IT infrastructure with ease.    

As enterprises increasingly prefer Terraform for their infrastructure automation, the demand for Terraform professionals continually increases. Terraform offers various job roles, including Terraform Architect, Terraform Engineer, DevOps Engineer, Terraform Developer, and more, leading to numerous job opportunities.

To help you prepare for your interview, I have collected the essential Terraform interview questions with detailed answers in this blog. After going through the blog, you can confidently face Terraform interviews and secure lucrative job opportunities in top companies.

Table of Contents:

• Skills Required
• Job Responsibilities
• Terraform Interview Questions
  • Freshers
  • Experienced
• FAQ's

Top 10 Frequently Asked Terraform Interview Questions

1. What exactly do you mean by Terraform in AWS?
2. Is it feasible to use callbacks with Terraform on Azure?
3. What is a Terraform cloud?
4. What are Terraform modules?
5. List all of Terraform's version control options.
6. What are the components that make up Terraform architecture?
7. In Terraform, How Do I Store Sensitive Data?
8. What is a tainted resource?
9. Provide the terraform settings for a single AWS EC2 instance.

Skills Required for Terraform Developers:

Before we dive into Terraform interview questions, we will look at the skillset of Terraform developers. In this section, I have listed the essential primary and secondary skills that current employers seek from Terraform developers.

Let’s see what they are!

Primary Skills:

• Sound knowledge of Terraform fundamentals
• Proficient with programming languages such as Python, JSON, YAML, etc.
• In-depth understanding of cloud computing concepts and cloud-based DevOps practices
• Familiar with well-known cloud service providers such as GCP,  AWS, and Azure.
• Deep understanding of CI/CD pipelines using Jenkins
• Familiar with source code management tools like Git
• Proficient with container orchestration tools such as Kubernetes and Docker
• Familiar with the Shell scripting language
• Strong exposure to Terraform CLI and workflows
• Familiar with Linux and Windows operating systems

Secondary Skills:

• Decent knowledge of Agile and Scrum methodologies
• Familiar with information security and monitoring tools
• Familiar with operational frameworks like GitOps
• Good understanding of Microservices architecture
• Proficient with tracking key application performance metrics
• Exposure to monitoring tools such as Grafana and Prometheus
• Exceptional analytical and problem-solving skills
• Good collaboration and communication skills

Sure! By understanding the Terraform developer's skillset, you can prepare well for Terraform interviews and ace your interviews intelligently.

Job Responsibilities of Terraform Developers:

In this section, I have included the job responsibilities of Terraform developers at various expertise levels. It will help you understand the role of Terraform developers in the workplace and sharpen your Terraform interview preparation.

Here we go!

Entry-level (0-2 Years of Experience)

• Writing simple, clean, quality codes for IT infrastructure provisioning
• Ensuring smooth implementation of infrastructure provisioning
• Managing containers using various containerisation tools
• Developing shell scripts to configure IT infrastructure
• Troubleshooting issues related to IT infrastructure automation
• Conducting information security scanning
• Developing delivery pipelines and deploying in production environments
• Implementing automated CI/CD pipelines at scale

Intermediate (3-5 Years of Experience)

• Performing IT provisioning with improved scalability, security, and availability
• Orchestrating containers using the Kubernetes
• Tightly monitoring the performance of resources and troubleshooting issues for enhanced performance
• Developing and deploying vault authentication and secret engines               
• Monitoring and optimising the Terraform-managed infrastructure
• Collaborating with cross-functional teams to implement provisioning as per requirements
• Closely interacting with clients to understand their requirements
• Maintaining documentation related to configurations and provisioning

Senior Level (More than Five Years of Experience)

• Implementing best practices for infrastructure reliability, security, and fault tolerance
• Designing and deploying GCP IAM configurations to make secure access to GCP
• Designing, developing, and deploying IT infrastructure in various cloud platforms
• Developing and automating the deployment of cloud architecture
• Implement best practices for provisioning, including continuous integration, version control, etc.
• Performing peer code reviews and mentoring junior developers for improvements

We hope that you have become familiar with the job responsibilities of Terraform professionals. It will help you to excel in your job from day one.

If you want to enrich your career and become a professional in Terraform, then enrol in "Terraform Online Training" - This course will help you to achieve excellence in this domain.

Terraform Interview Questions:

In this section, I have meticulously hand-picked the top 50 Terraform interview questions for your adequate preparation. I have also divided this section into two categories for beginners and advanced learners. So, you will gradually learn Terraform from the basics to the advanced level.

Top Terraform Interview Questions For Freshers

I have included the basic Terraform questions and answers in this section to provide a solid foundation on Terraform concepts. In this part, you will learn about Infrastructure as Code, Terraform modules, Terraform commands, and many more.

1. What is Terraform?

Terraform is a DevOps tool that we use to automate infrastructure provisioning. Also, it is an Infrastructure as a Code (IaC) tool with which we can build and modify on-premises and cloud resources efficiently.

2. What exactly do you mean by Terraform in AWS?

Terraform supports designing, updating, and versioning Amazon Web Services (AWS) infrastructure. Terraform in AWS is part of the AWS DevOps competency and an advanced AWS Partner Network (APN) technology.

With Terraform's custom AWS CloudFormation, we can control the on-premises and public cloud resources. We may access the resources directly from the CloudFormation user interface. We can also access the resources through the AWS Service catalogue, which provides an extra degree of governance and control.

3. What are the critical aspects of Terraform?

The essential features of Terraform are given as follows:

• Terraform offers excellent state management features. It compares the current state of the infrastructure with the user-defined infrastructure. As a result, Terraform builds the blueprint of the desired infrastructure.
• It has a robust console enables users to monitor the functions in action. 
• It creates an execution plan automatically based on user requirements. Terraform will start building the infrastructure only when we approve the plan. It will reduce unnecessary changes in the infrastructure in the future and improve efficiency.
• Terraform’s module count helps track the number of modules installed on the infrastructure.

4. What is IaC?

Infrastructure as Code (IaC) is the software approach in which developers use code to build, modify, and maintain an IT infrastructure using configuration files. The IT provisioning is done automatically, replacing the manual efforts. Note that we can alter and transfer configuration files securely within the organisation.

5. What is the latest version of Terraform?

The latest stable release of Terraform is v1.8.4, which was released on May 22, 2024.

6. Can you tell us some of the crucial Terraform commands?

The crucial Terraform commands are:

• Terraform Refresh – This command updates state files.
• Terraform Apply – This command executes Terraform codes and creates objects.
• Terraform Output – This command allows viewing Terraform outputs.
• Terraform Graph – This command generates graphs in DOT format.
• Terraform Destroy – This command destroys the already-built IT infrastructure.
• Terraform Init – This command creates a new directory in the current directory.
• Terraform Plan – This command creates an execution plan. The plan supports previewing the changes that Terraform will make in an infrastructure.
• Terraform Validate – This command validates the configuration files stored in a directory.

7. Is it feasible to use callbacks with Terraform on Azure?

Callbacks are possible with Terraform on Azure if you use Azure Event Hubs. Terraform's Azure supplier offers users simple functionality. The Terraform occurrence has already been set up in Microsoft Azure Cloud Shell.

8. What is Terraform init, and how does it work?

Terraform init is a Terraform command that initialises the configuration files stored in a working directory. It is the first command we execute after creating a new Terraform design. It allows setting up an operational index using the Terraform pattern files. We can repeat this operation several times. 

9. What are the new updates included in the latest version of Terraform?

The following are a few updates made in the latest version of Terraform (v1.8.4).

• Earlier, when the modules of the Terraform configurations used the meta-argument, there were exponential slowdowns in IT infrastructures. The latest version of Terraform (v1.8.4) removes this drawback.
  
• The new golang.org/x/net release has been updated in Terraform to the latest version. This update increases security by limiting excess header frames we pass before closing a connection.
  
• When resources were nested and computed, the optional ID attributes failed to generate configuration in the earlier versions. The latest version overcomes this setback.
  

10. What is Terraform D, and how does it work?

Terraform D is a Windows plugin that works with almost all in-service systems. By default, Terraform init looks for plugins in the following directory.

11. What are the primary responsibilities of Terraform provider plugins?

The primary responsibilities of a Terraform provider plugin include:

• Initialising libraries to make API calls
  
• Defining managed resources and data sources associated with specific services
  
• Authenticating with the infrastructure provider
  
• Defining functions that simplify computational logic for configurations
  

12. If you use the TFS API to deliver resources, can you use the same for the web?

Yes, we can use Team Foundation Service (TFS) API to deliver resources for the web, too. The user interface uses API as its foundation in this scenario. 

13. What is the role of Terraform in DevOps?

DevOps engineers employ Terraform to automate infrastructure provisioning. They use Hashicorp Configuration Language (HCL) to script human-readable configuration files. We can reuse and share the configuration files.

HCL provides many commands that allow DevOps engineers to build and apply infrastructure settings across multiple cloud environments and on-premises data centres.

Related Article: DevOps Tutorial

14. What is the purpose of using the null resource in Terraform?

The null resource in Terraform is the same as the standard resource, which follows the resource lifecycle model. It acts as a placeholder to execute arbitrary actions included in Terraform configurations. However, it doesn’t perform any action other than initialisation.

15. What is a Terraform cloud?

Terraform Cloud is a platform that supports managing Terraform codes. It bridges the gap between DevOps engineers and developer teams, simplifying workflows and improving security.

Workspace is one of the crucial components of the Terraform Cloud. It plays a vital role in storing states, executing runs, and storing environment variables. Moreover, the project is another Terraform Cloud component that contains workspaces.

16. Describe Oracle Cloud Infrastructure.

Oracle Cloud infrastructure is essentially a cloud computing platform comprising storage, applications, servers, services, and networks. We can access these resources from the global network of Oracle Corporation-managed data centres anytime.

17. What is "terraform backend"?

We can define a Terraform backend in any Terraform setup. We use a Terraform backend to determine the location for storing state data files. It allows multiple users to access the state data and collaborate.

Local is one of the Terraform backends we can use to store state files as local files in the current working directory. If the configuration doesn’t include any backend block, Terraform assumes the local backend as the default. 

18. What version control systems does Terraform support apart from GitHub?

Terraform supports the following Terraform versions.

• GitLab EE
• GitLab CE
• Bucket cloud.

19. Which companies are the key competitors of Terraform enterprise?

Terraform's key competitors are:

• Azure Management Tools
• VMware Aria Cost
• Morpheus
• Apptio Cloudability
• CloudHealth
• ServiceNow IT Operations Management
• IBM Turbonomic
• CloudBolt

20. What is the use of Terraform CLI?

We use Terraform's Command-Line Interface (CLI) to manage infrastructure. Not only that, we use the CLI to communicate with Terraform state and configuration files.

21. Can you list the crucial Terraform version control options?

Terraform supports the following version control options:

• Azure DevOps Services.
• Azure DevOps Server
• Cloud Bitbucket
• Bitbucket Server
• GitLab Enterprise Edition (EE) and Enterprise Edition (CE)
• GitLab
• GitHub(OAuth)
• GitHub Enterprise
• GitHub

Terraform Interview Questions For Experienced

I have curated the advanced Terraform interview questions in this section to enhance your Terraform expertise. Once you complete reading this section, you will gain in-depth knowledge of various key terraform topics.

22. What is the purpose of Terraform CLI, and what are some common CLI commands?

Terraform's Command-Line Interface (CLI) is used to manage infrastructure and communicate with Terraform state, configuration files, and providers, among other things.

Here are some simple CLI commands to get you started:

• Terraform init - Sets up your working directory to run additional commands.
• Terraform destroy - Destroys the infrastructure you've already built.
• Terraform validate - Check if the configuration is correct using terraform validate.
• Terraform apply - This command develops or changes infrastructure.
• Terraform plan - Depicts the modifications that the existing arrangement necessitates.

23. What are Terraform modules?

A module in Terraform is typically a container that has multiple resources. We use modules to pack and reuse Terraform configurations to boost productivity.

Terraform has three modules:  Root, Child, and Published.

• Root Module: Every Terraform configuration will contain the root module, which includes the .tf files.
• Child Module: In Terraform, a module can be called by another module. Once the calling is done, the resources of the called module are included in the module that calls. The called module is known as the child module.
• Published Module: These modules are loaded into a public or private registry. Anyone can make seamless access to the public modules. Similarly, published modules can use the modules published by others.

24. What is a Private Module Registry, and how does it work?

Terraform’s Private Module Registry allows developers to distribute Terraform modules and providers across the organisation. The private module registry works in the same way as the public registry. Further, it provides support for versioning and a list of available modules and providers.

25. Can Terraform be used to build on-premises infrastructure?

Yes, we can use Terraform to create on-premises infrastructure. We can configure the infrastructure based on user requirements.

26. Can you use Terraform to deploy several providers?

Yes, Terraform supports multi-provider installations. It includes on-premises solutions like VMware, OpenStack , and SDN management.\

27. How can you avoid a duplicate resource error during the Terraform application?

We can avoid the duplicate resource error with the following options:

• Deleting resources from the cloud provider's API and rebuilding them with Terraform.
• Preventing Terraform from managing specific resources and removing them from the code.
• Deleting the codes that attempt to replicate.

28. List all of Terraform's version control options.

The following version controls are supported:

• Azure DevOps Services.
• Azure DevOps Server
• Bitbucket Server
• Cloud Bitbucket
• Gitlab Enterprise Edition (EE) and Enterprise Edition (CE)
• Gitlab.com
• GitHub Enterprise.
• GitHub.com (OAuth)
• GitHub.com

29. What are the pre-installed Terraform provisioners?

The pre-installed Terraform provisioners are:

• Provisioner without a salt-master
• Provisioner of puppets
• Provisioner for remote execution
• Provisioner with local authority
• Provisioner of files
• Provider of habitat
• Provisioner chef

30. What command is used to remove Terraform-managed infrastructure?

We use the following command to remove a Terraform-managed infrastructure.

[options] [dir] terraform destroy

31. Can you tell us some significant Terraform applications?

The following are some of the significant applications of Terraform:

• Deploy, scale, and monitor IT infrastructure for multi-tier applications
• Build a self-service infrastructure model
• Set up the Heroku application
• Supports multi-cloud deployment
• Compliance policy and management
• Configuring networks with SDNs

32. What are the components that makeup Terraform's architecture?

Jotted down are the key components of terraform architecture.

• Terraform core
• Providers
• State file

33. What is a Resource Graph in Terraform?

Terraform creates a resource graph based on the configuration details. We can use this graph to build execution plans, refresh state files, and more. A resource graph in Terraform shows resources that allow for developing and modifying resources at a time.

Terraform’s execution plan supports updating the state of a resource graph’s configuration. We can also identify the drawbacks of the resources from the graph at a glance.

Celebrate! I’m sure that you are thorough in Terraform fundamentals. No doubt you are now ready to jump into learning advanced interview questions.

34. Can you list out some of the Sentinel policies?

Below are a few examples of sentinel policies: 

• Making unambiguous resource ownership is a must
• Examining the Terraform Cloud Operations Audit Trail
• Limiting the roles that the cloud provider can play
• Preventing only the particular services, resources, or data sources
• Making resource labelling obligatory
• Limiting the use of modules in the Private Module Registry

35. What are the different degrees of Sentinel policing?

There are three degrees of enforcement in Sentinel: advisory, soft mandatory, and hard obligatory.

• Advisory - You've been logged in, but you're free to leave. When a user initiates a plan that violates the rules, an advisory is sent.
  
• Soft Mandatory - Unless an override is stated, the policy must pass. Overrides are only available to administrators.
  
• Hard Mandatory - The policy must pass regardless of the circumstances. Unless it is abolished, this policy cannot be overridden. In Terraform, this is the default enforcement level.
  

[ Check out: Terraform Private Registry]

36. In Terraform, How Do I Store Sensitive Data?

Terraform requires credentials to interact with your cloud provider's API. These credentials, on the other hand, are typically left unencrypted on your desktop. Significant numbers of API and cryptographic keys are exposed to GitHub every day. As a result, you should never save your API keys explicitly in Terraform code. Anything that shouldn't be retained in plain text, such as passwords, TLS certificates, and SSH keys, should be encrypted.

37. What is the difference between DevOps and GitOps?

GitOps	DevOps
It is a branch of DevOps that focuses on Git code repositories for code deployment and infrastructure management.	It bridges the gap between the development and IT operations teams tightly.
It mainly depends on automation for code management and deployment.	It heavily depends on communication and collaboration between teams.
We use GitOps in conjunction with any containerisation tool.	We use DevOps with any application
The Git repository is essentially the source of truth in GitOps.	Application or server configuration files are the source of truth in DevOps.

38. How will you load critical data in Terraform?

We must use credentials to interact with any cloud provider API to store the sensitive data.

Frequently Asked Questions

39. What is Terragrunt, and how does it help you?

Terragrunt is a lightweight wrapper for Terraform that offers extra capabilities, including DRY setups, remote state management, and support for a variety of Terraform modules. It is employed for the following purposes:

• Managing numerous Amazon Web Services accounts
  
• Numerous Terraform commands are being executed on multiple modules.
  
• DRYING OUT OUR CLI FLAGS
  
• Maintaining the setting of our remote state DRY.
  
• We're going to keep our Terraform code. DRY
  

40. What is the use of state file locking?

State file locking is one of Terraform's backend procedures. This method prevents multiple users to perform the same task. Only when a user exits a task can other users access that task. It helps to keep state files from becoming corrupted.

41. What is a "tainted resource"?

We can delete and regenerate a tainted resource by using Terraform commands. When a resource is identified as contaminated, the state files are changed. But at the same time, the infrastructure remains the same. 

42. How can you lock Terraform module versions?

We can lock Terraform module versions by leveraging the Terraform module registry as a source. Also, we can use the Terraform configuration file version attribute.

43. What are Terraform Core's primary responsibilities?

Terraform Core is a compiled binary written in the Go language.

The primary responsibilities of the Terraform Core are given as follows:

• Interpolates modules
• Constructs resource graphs
• Manages the current status of resources
• Makes connections between plugins

44. Provide the terraform settings for a single AWS EC2 instance.

The Terraform setup for launching a single EC2 instance on AWS is given as follows:

"AWS" as a provider
"region" = "
"AWS instance" is a resource.
"as an example"
"" = ami
"" instance type="" instance type="" instance type="" instance_
tagging
"example" as a name

Related Article: AWS EC2 Tutorial

45. How will you upgrade Terraform plugins?

When executing 'Terraform init,' we must use the '-upgrade' option. This command looks for the acceptable new provider versions in the repository. If they are available, it also downloads the versions.

46. How will you make a high-level object from one module available to the other?

In resource configuration, an output variable is defined.

• Declare module A's output variable.
• Create a variable.tf file for module B.
• Create an input variable with the same name defined in module B in the created file.
• Repeat the procedure to make variables accessible to other modules.

47. What are some of the most recent Terraform Azure Provider considerations?

New data resources, such as Azure batch certificates, are provided in recent editions. We use this resource to control things when networking.

48. How will you manage and regulate rollbacks if something goes wrong?

We must recommit the earlier code version to make it new. It will start the Terraform run command by running the earlier code. Terraform is highly declarative, so the codes will soon be reverted to their previous state. If the state file is damaged, we can use the Terraform enterprise rollback feature to restore the earlier details.

49. What are the best practices to monitor a Terraform enterprise instance?

• Health Check: When the Terraform instance works well, the health check will return 200 OK. The health check endpoint works in two modes: full and minimal checks.
• Grafana Dashboard: We can use Grafana and Prometheus to visualise Terraform enterprise metrics.
• Metrics and Telemetry: We can monitor the server metrics on the Terraform instance, such as I/O, CPU, RAM, and disk.

50. Should you run ‘Terraform init’ before running every ‘Terraform plan’?

It depends on the configuration scenario. If we have made changes in the configured backend, we must re-run ‘Terraform init’ to re-initialize the configuration. If we have changed the non-Terraform configuration codes, executing only the ‘Terraform plan’ is enough.

But at the same time, if we are making changes in modules, we must re-run the ‘Terraform get-update’ to include the changes in the configuration.

51. Can you use callbacks with Terraform on Azure?

Yes, it is possible to use callbacks with Terraform on Microsoft Azure. For instance, we can send a callback to a trigger, logging system, or any event. We can use callbacks only when we use Azure Event Hubs.

52. What is the critical difference between Terraform Init and Terraform Apply?

The Terraform Init command initialises the configuration files stored in a working directory. It is the first command that we run after writing the configuration scripts. Note that we must run this command multiple times to avoid errors.

On the other hand, the ‘Terraform Apply’ command executes the actions of a Terraform plan. First, this command assesses the current infrastructure, identifies the gaps, and updates resources based on the plan.

53. How do you validate the Terraform file?

We can use the Terraform validate command to validate configuration files in a working directory. This command examines the configuration files to determine whether they are syntactically correct and consistent. Besides, we validate the files to verify the reusable modules by examining the accuracy of attribute names and value types.

We must run this command safely in two ways. One way is to run this command as a post-save check in a text editor. Another way is to run this command as a test step for a reusable module in a continuous integration system.

54. How does Terraform support streamlining environments?

Terraform is an IaC tool that can streamline multi-environments with a single codebase. In other words, we can use the same configuration files to provision resources across multiple environments without compromising consistency.

Additionally, we can use modules, workspaces, and variables to streamline multi-environments.

55. What do you mean by Terraform remote state management?

Terraform stores state files in a local directory by default. When multiple users access the state files, it leads to severe complications. However, Terraform stores state files in a remote data store when we employ the remote state. So, all the users can access the data in the state files simultaneously without any complications.

Know that Terraform stores state files in the HCP Terraform, Amazon S3, Hashicorp Consul, and Google Cloud storage.

56. Compare Continuous Integration, Continuous Delivery, and Continuous Deployment.

• Continuous Integration: A DevOps practice where developers frequently merge code changes into the source repository. We apply continuous integration to remove bugs in codes, improve software quality, reduce the validation time and release new software updates.
• Continuous Delivery: It is a devops practice where the code changes are prepared to be automatically released into a testing or production environment. Before moving into the production environment, the codes must pass the automated unit, UI, integration, and load testing.
• Continuous Deployment: In this devops practice, all code changes are automatically released into a production environment. Once a new build passes the tests, it will be pushed into a production environment. Continuous deployment mainly increases the time to market for the latest updates.

Cheers! Now, you are supercharged with learning all the Terraform interview questions and answers. We hope you are ready to nail your Terraform interviews and climb your career ladder.

Freaquently Asked Questions

1. Is Terraform easy to learn?

 Yes, Terraform is easy to learn. You will quickly learn to Terraform if you provide sheer focus, dedication, and practice. Learning Terraform is a piece of cake if you polish your DevOps skills. MindMajix delivers top-class Terraform training from industry-experienced trainers. The cutting-edge course modules will boost your Terraform knowledge to new levels. Your learning journey in MindMajix will be smooth, seamless, and fruitful.

2. Is learning to Terraform worth it?

 Yes, learning Terraform is a big investment for your future. According to Glassdoor, Terraform developers can get an average base pay of over 9 LPA in India. In the USA, Terraform DevOps engineers make over 150k USD per year, according to Talent. These figures are indeed attractive and hopeful. So, learning Terraform is a great choice. You can kick start your career with confidence.

3. How hard is the Terraform certification exam?

Harshicorp offers Terraform associate certification for DevOps professionals to test their knowledge of Terraform professionals. The certification proves you can showcase your expertise to recruiters and smoothly breeze through your Terraform interviews. MindMajix offers in-depth Terraform training for all learners. It empowers anyone with zero or any expertise to positively crack the Terraform certification exam on the very first attempt.

4. What are the prerequisites to learn Terraform?

 Indeed, there is no prerequisite to learning Terraform. However, if you have good exposure to the following, it will be a significant advantage.

• Basic programming knowledge of Java and JavaScript
• Exposure to variables, functions, nested maps, and expressions
• Familiar with popular cloud providers like Azure, GCP, and AWS
• Decent working knowledge of Command Line Interface (CLI)

5. How many days does it take to learn to Terraform?

 You can truly learn Terraform in a short span. MindMajix offers 50 hours of standalone Terraform training in two modes – live instructor-led and self-paced videos. You will learn Terraform within 15 days if you prefer live online training. On the other hand, if you choose the self-paced video mode, you will learn Terraform within 15 days by watching videos three hours per day.

Conclusion

Terraform interviews may be tough at times, therefore familiarity with the platform is essential. It's advisable to keep exploring and experimenting with the platform to improve your chances of passing the interview.