Terraform Essentials - Learn DevOps & Infrastructure as Code

Understand declarative versus imperative programming through a grocery shopping analogy, and see how Terraform applies declarative infrastructure as code to provision AWS resources.

Understand how Terraform handles errors and provisions cloud resources, not the run-time configuration. Prefer prebuilt images like AMIs or Docker images and tools such as Ansible or Puppet for setup.

Learn how Terraform is an open source infrastructure as code tool that uses a declarative configuration to provision resources across AWS, Azure, and GCP, via a consistent CLI workflow.

Terraform verifies that your deployed infrastructure matches the specified state and supports setting auto scaling bounds, while true dynamic scaling is managed by cloud providers like Beanstalk or Azure.

Track existing resources with Terraform by checking state, so you provision only what's missing and enjoy idempotent deployments that handle intermittent errors.

Install Terraform as a single go-compiled executable added to your path across Windows, Mac, and Linux, including Docker usage. Install via Homebrew by tapping HashiCorp on Mac.

Download the correct Windows version of Terraform, extract the zip, place the binary in a bin directory, and add its path to environment variables to access Terraform from the CLI.

Authenticate Terraform with AWS by configuring the AWS CLI and credentials in the ~/.aws folder; avoid putting keys in Terraform files, and let Terraform piggyback on the AWS CLI.

Create a Terraform project as a folder, use VS Code for coding, configure the AWS provider with region and profile, then define resources like EC2 and S3 with their parameters.

Initialize a Terraform project, run plan to compare desired state with the current infrastructure, and apply to create an AWS EC2 instance as part of infrastructure as code.

Explore why Terraform apply runs a plan again, since it doesn't remember the plan between operations, and how saving the plan lets it remember for execution.

Explore idempotency in Terraform by planning, applying, and verifying that AWS resources match configuration, then destroy resources with Terraform destroy, seeing state refresh and resource termination.

Capture the plan to a file with the -out option, using the tf plan extension, then apply that plan file with Terraform apply to execute exactly what was planned.

Learn how to create an AWS S3 bucket with Terraform by copying resource definitions from the registry, running plan and apply, and leveraging parallel execution.

Learn how Terraform names create in-scope objects to reference resources, use tags to assign AWS names, and apply updates to label EC2 instances and S3 buckets.

Explore how terraform updates differ from recreating resources, showing in-place changes like instance type tweaks versus destroy and recreate when changing an ami, using plan and apply.

Install the HashiCorp Terraform extension in VS Code to enable syntax highlighting and auto completion for providers and resources, and learn to run terraform init for a productive workflow.

Explore how Terraform uses provider and resource blocks to configure AWS and Azure, manage credentials with Terraform CLI, and understand how changes affect immutable resources like AMI and S3 bucket.

Terraform init scans main.tf, downloads the AWS provider into the dot terraform folder, and enables Terraform to invoke provider executables from the official HashiCorp Terraform registry to manage AWS resources.

The tfstate file records infrastructure state, tracking AWS resources like the EC2 instance and S3 bucket from Main.tf, so plan refreshes state and applies changes to match the ideal state.

Lock external dependencies, providers and modules, versions with the lock file created by terraform init to ensure deterministic runs; upgrade with terraform init -upgrade and update .terraform.lock.hcl.

Explain how to use the Terraform block to configure Terraform, set required versions, and declare providers with sources and local names, including the AWS provider from HashiCorp registry.

Explore the HashiCorp configuration language used by Terraform, focusing on blocks, labels, and identifier equals expressions to define resources. Understand comment styles and how Terraform fmt enforces readable formatting.

Explore how Terraform uses variables to avoid repetition when configuring an AWS VPC with CIDR blocks and subnets. See a practical use case for app naming to keep tags consistent.

Explore Terraform input variables: define a variable block with name, type, default, and description; reference with the var namespace, and apply validation, sensitive, and nullable options across modules.

Learn how to supply values to Terraform input variables using defaults, the CLI -var option, and environment variables to parameterize plans and deployments.

Deploy an ec2 instance with terraform, using user data to launch a busybox httpd on port 8080 and serve a simple html page, with a security group allowing 8080.

Learn how to use Terraform output variables to expose resource properties like a web server's public IP, print them to the console, and reuse them across resources or scripts.

Master best practices for organizing Terraform variables, using variables.tf and terraform.tfvars, distinguishing input variables from defaults, and letting Terraform scan the root folder for all variable definitions.

Discover how string interpolation in HCL embeds variables in strings to create resource tags like EC2 app and SG app, and to build dynamic CIDR blocks with var.ip and var.range.

Explore Terraform variable types, including string, number, boolean, list, map, object, set, tuple, and any, with practical examples and how to declare, interpolate, and use them in plans and outputs.

Learn how to use local variables in Terraform by defining values with the locals block and referencing them as local.http_port to reuse data without inputs.

Learn how to manage Terraform in teams with ci/cd, avoid checking in state, keep master and deployment in parity, and understand automatic pipeline runs on merge amid stateless pipelines.

Learn how Terraform uses a foreach loop to create multiple S3 buckets from a list of unique names, using var.bucket_names, each.value, and set to deduplicate.

Explore the count property that creates multiple Terraform resources from a single block. Use count dot index and square bracket notation with string interpolation to generate unique names.

Explore data variables in Terraform to query external data from AWS, such as the default VPC, subnet IDs, and latest AMI IDs, and understand the non-deterministic risks and best practices.

Learn how Terraform builds an internal dependency graph to determine execution order, exportable as json and Graphviz diagrams, and visualize resources, providers, and their dependencies.

Discover real world terraform challenges in teams, including managing multiple environments and multiple developers, and learn why workspaces offer scalable solutions for dev, qa, and prod.

Learn to manage multiple environments with Terraform workspaces, switching between dev, prod, and QA, using commands like list, new, select, and show to keep separate state.

Use terraform workspaces to prevent name clashes and tailor resources per environment. Configure workspace-specific names and sizes with terraform.workspace, and use modules to share configurations across dev, qa, and prod.

Use a remote backend to share Terraform state across a team, storing it in an S3 bucket. Enable locking with DynamoDB to prevent concurrent applies and configure the backend accordingly.

Learn how to create and reuse Terraform modules, structure root and submodules, declare module sources, and initialize with Terraform init to share infrastructure code.

Define module input variables, such as bucket name, in variable.tf and pass values from the root module to the module for reusable, configurable s3 bucket creation.

Utilize Terraform registry modules to reuse someone else's code for infrastructure, such as VPCs and security groups, by configuring remote modules with required variables and running terraform init.

Recap the essentials of infrastructure as code with Terraform, including declarative workflows and the init, plan, and apply cycle. Understand tf state management and modules for reusable infrastructure.