While each of the main public cloud providers has its own version of Infrastructure as Code (ARM, AWS CloudFormation, etc.), adopting the native solution can be limiting as the organization matures its cloud capabilities and offerings. If the organization only learns the native solution, what happens if they decide to use a different public cloud provider or they acquire a company that uses a different one? While the developer mindset would still apply, the skillset used to deploy ARM doesn't necessarily apply one-to-one for writing AWS CloudFormation, for example. Each of these solutions handles development and deployment differently, and the engineers have to learn a second solution.

By using Terraform, engineers and developers can focus their time on learning a single solution applicable to all the public cloud providers and other SaaS, PaaS, and IaaS offerings available on the market.

Wrong Answers:

The wrong answers are all benefits of using any infrastructure as code, such as standardization, reusability, and familiarity with using a cloud provider solution.

https://www.terraform.io/intro/use-cases#multi-cloud-deployment

https://www.terraform.io/intro/vs/cloudformation

Terraform includes the ability to use the command terraform apply -refresh-only to refresh the local state based on the changes made outside of the Terraform workflow. Terraform will use the platform's API to query information about each known/managed resource and update any changes it finds.

IMPORTANT - READ THIS!!!!

terraform apply -refresh-only replaced the deprecated command terraform refresh. However, you still may find terraform refresh in the real exam until it gets updated. Keep this in mind when taking the real exam. HashiCorp does update the exams very often, and this could very well come out at the beginning of 2022 when they overhaul the existing exam as noted on the exam page that a new version would be released in early 2022.

WRONG ANSWERS:

terraform plan -out=refresh just runs a terraform plan and saves a plan called refresh. I was being a little tricky here but just know that this isn't how to refresh your state file

terraform init -upgrade is the command to use if you want Terraform to upgrade your existing downloaded providers

terraform get -update is used to download and update modules that are referenced in your Terraform configuration files

https://www.terraform.io/cli/commands/refresh

Oddly enough, the -refresh-only option doesn't currently exist as a valid option on the terraform apply documentation - if it does show up, let me know so I can update this description

The primary use case for IaC is to deploy and configure resources in almost any environment in a single, unified way that also abstracts the user from the APIs.

Wrong Answers:

Combing disparate technologies and tasks is really the job of a pipeline, such as GitLab CI/CD, Jenkins, or Azure DevOps. While Terraform CAN be used with multiple technologies within a single configuration file, it's not really the ideal job for Terraform. Terraform isn't an orchestrator like the aforementioned tools would be used for.

The goal of Terraform is NOT to ensure that operations folks know how to develop code, although I'd say that is somewhat of an end result in most organizations. While they are developing Java or Golang applications, operations folks tend to use Terraform as an opportunity to learn more developer-centric workflows, like using Git or learning how to develop code in a repeatable fashion.

When deploying Terraform, it's often a one-time thing, and Terraform doesn't actively monitor applications for changes. That's the job of a configuration management tool, such as Ansible, Chef, Puppet, or SaltStack.

https://www.terraform.io/intro/use-cases

https://www.terraform.io/intro/vs/chef-puppet

https://www.terraform.io/intro/vs

In this case, automation is key. And considering that this is a course/question focused on Infrastructure as Code, developing IaC to trigger automatically based on workloads is the best answer here.

Wrong Answers:

While the others sound like a great idea or an improvement in the troubleshooting process, they wouldn't resolve the errors with their customers.

https://www.terraform.io/intro

https://www.terraform.io/intro/use-cases

While it's not required, we recommend explicitly constraining the acceptable version numbers to avoid unexpected or unwanted changes. Use the version argument in the module block to specify versions.

module "consul" {

 source = "hashicorp/consul/aws"

 version = "0.0.5"

 servers = 3

}

https://www.terraform.io/language/expressions/version-constraints

When setting Terraform required_version or provider constraints, the ~ specifies that only the right-most version number can be incremented - therefore only v1.0.5 will satisfy the requirements.

https://www.terraform.io/language/providers/requirements#best-practices-for-provider-versions

A local value assigns a name to an expression, so you can use it multiple times within a configuration without repeating it. The expressions in local values are not limited to literal constants; they can also reference other values in the configuration in order to transform or combine them, including variables, resource attributes, or other local values.

You can use local values to simplify your Terraform configuration and avoid repetition. Local values (locals) can also help you write a more readable configuration by using meaningful names rather than hard-coding values. If overused they can also make a configuration hard to read by future maintainers by hiding the actual values used.

Use local values only in moderation, in situations where a single value or result is used in many places and that value is likely to be changed in the future. The ability to easily change the value in a central place is the key advantage of local values.

https://www.terraform.io/language/values/locals

To accomplish this, you can delete the resource from state so Terraform no longer knows anything about it. Then you can run a terraform destroy to destroy the remaining resources. During the destroy, Terraform won't touch the web server since it is no longer managing it. This is similar to how Terraform won't impact existing resources that it does not know about when creating, modifying, and destroying resources in your local or public cloud infrastructure.

To delete a resource from state, you can use the terraform state rm <address> command, which will effectively make Terraform "forget" the object while it continues to exist in the remote system.

WRONG ANSWERS:

change to new workspace and run terraform destroy - changing to a different workspace would have no impact on any resources in the current workspace. It could, however, impact any resources that were provisioned with the second workspace that you change to

terraform import & terraform destroy - using the import command here is basically the opposite of what we want to do. We want Terraform to "forget" about a particular resource, and the import command pulls existing resources under Terraform management

delete the block and run terraform apply - this would actually destroy ONLY the web server that we want to keep, so essentially doing the exact opposite of what we're trying to accomplish

https://www.terraform.io/cli/commands/state/rm

Workspaces should be used in this scenario to create separate state files for each regional deployment. When you use a workspace in Terraform OSS, you get a brand new state file to work with that is completely separate from the original. Therefore, you can modify environment variables or other values and use the same Terraform without negatively impacting resources that were deployed in any other workspace.

To create a new workspace, you can use the command terraform workspace new <name>

WRONG ANSWERS:

terraform plan - this command compares the current infrastructure against the desired state (configuration file) and proposes changes to your infrastructure. This is also commonly referred to as a dry run.

terraform get - this command is used to download modules

terraform import - this command can be used to import existing resources and pull them under Terraform management

https://www.terraform.io/language/state/workspaces

This is true, although there are tools out there that have UIs to deploy IaC. However, the goal is to reduce or eliminate the need to use a UI to deploy infrastructure and applications.

https://learn.hashicorp.com/tutorials/terraform/infrastructure-as-code