What is Infrastructure as Code? You write and execute the code to define, deploy, update, and destroy your infrastructure What are the benefits of IaC? a. Automation We can bring up the servers with one script and scale up and down based on our load with the same script. b. Reusability of the code We can reuse the same code c. Versioning We can check it into version control and we get versioning. Now we can see an incremental history of who changed what, how is our infrastructure actually defined at any given point of time, and we have this transparency of documentation. IaC makes changes idempotent, consistent, repeatable, and predictable. How using IaC make it easy to provision infrastructure? IaC makes it easy to provision and apply infrastructure configurations, saving time. It standardizes workflows across different infrastructure providers (e.g., VMware, AWS, Azure, GCP, etc.) by using a common syntax across all of them. What is Ideompodent in terms of IaC? The idempotent characteristic provided by IaC tools ensures that, even if the same code is applied multiple times, the result remains the same. What are Day 0 and Day 1 activities? IaC can be applied throughout the lifecycle, both on the initial build, as well as throughout the life of the infrastructure. Commonly, these are referred to as Day 0 and Day 1 activities. "Day 0" code provisions and configures your initial infrastructure. "Day 1" refers to OS and application configurations you apply after you've initially built your infrastructure. What are the use cases of Terraform? Heroku App Setup Multi-Tier Applications Self-Service Clusters Software Demos Disposable Environments Software Defined Networking Resource Schedulers Multi-Cloud Deployment https://www.terraform.io/intro/use-cases.html What are the advantages of Terraform? Platform Agnostic State Management Operator Confidence https://learn.hashicorp.com/terraform/getting-started/intro Where do you describe all the components or your entire datacenter so that Terraform provision those? Configuration files ends with *.tf How can Terraform build infrastructure so efficiently? Terraform builds a graph of all your resources, and parallelizes the creation and modification of any nondependent resources. Because of this, Terraform builds infrastructure as efficiently as possible, and operators get insight into dependencies in their infrastructure. What is multi-cloud deployment? Provisioning your infrastructure into multiple cloud providers to increase fault-tolerance of your applications. How multi-cloud deployment is useful? By using only a single region or cloud provider, fault tolerance is limited by the availability of that provider. Having a multi-cloud deployment allows for more graceful recovery of the loss of a region or entire provider. What is cloud-agnostic in terms of provisioning tools? cloud-agnostic and allows a single configuration to be used to manage multiple providers, and to even handle cross-cloud dependencies. Is Terraform cloud-agostic? yes What is the use of terraform being cloud-agnostic? It simplifies management and orchestration, helping operators build large-scale multi-cloud infrastructures. What is the Terraform State? Every time you run Terraform, it records information about what infrastructure it created in a Terraform state file. By default, when you run Terraform in the folder /some/folder, Terraform creates the file /some/folder/terraform.tfstate. This file contains a custom JSON format that records a mapping from the Terraform resources in your configuration files to the representation of those resources in the real world. What is the purpose of the Terraform State? Mapping to the Real World Terraform requires some sort of database to map Terraform config to the real world because you can't find the same functionality in every cloud provider. You need to have some kind of mechanism to be cloudagnostic Metadata Terraform must also track metadata such as resource dependencies, pointer to the provider configuration that was most recently used with the resource in situations where multiple aliased providers are present. Performance When running a terraform plan, Terraform must know the current state of resources in order to effectively determine the changes that it needs to make to reach your desired configuration. For larger infrastructures, querying every resource is too slow. Many cloud providers do not provide APIs to query multiple resources at once, and the round trip time for each resource is hundreds of milliseconds. So, Terraform stores a cache of the attribute values for all resources in the state. This is the most optional feature of Terraform state and is done only as a performance improvement. Syncing When two people works on the same file and doing some changes to the infrastructure. Its very important for everyone to be working with the same state so that operations will be applied to the same remote objects. https://www.terraform.io/docs/state/purpose.html What is the name of the terraform state file? terraform.tfstate How do you install terraform on different OS? // Mac OS brew install terraform // Windows choco install terraform https://learn.hashicorp.com/terraform/getting-started/install How do you manually install terraform? step 1: Download the zip fille step 2: mv ~/Downloads/terraform /usr/local/bin/terraform Where do you put terraform configurations so that you can configure some behaviors of Terraform itself? The special terraform configuration block type is used to configure some behaviors of Terraform itself, such as requiring a minimum Terraform version to apply your configuration. terraform { # ... } Only constants are allowed inside the terraform block. Is this correct? Yes Within a terraform block, only constant values can be used; arguments may not refer to named objects such as resources, input variables, etc, and may not use any of the Terraform language built-in functions. What are the Providers? A provider is a plugin that Terraform uses to translate the API interactions with the service. A provider is responsible for understanding API interactions and exposing resources. Because Terraform can interact with any API, you can represent almost any infrastructure type as a resource in Terraform. https://www.terraform.io/docs/configuration/providers.html How do you configure a Provider? provider "google" { project = "acme-app"