Terraform

Tool	Description
Terragrunt	Terragrunt is a thin wrapper for Terraform that provides extra tools
Terracost	Cloud cost estimation for Terraform in your CLI
Infracost	Cloud cost estimates for Terraform in pull requests
TFLint	Terraform Linter

• Linux Academy - Using Terraform to Manage Applications and Infrastructure
• How To Structure a Terraform Project
• Creates a standalone Docker host on EC2
• Terraform’s Azure Provider to provision resources in Azure
• Docker the Terraform Way
• Terraform at Scale — Modualized Hierachical Layout and Continuous Delivery of Infrastructure

Instalation

# Download
TER_VER=`curl -s https://api.github.com/repos/hashicorp/terraform/releases/latest | grep tag_name | cut -d: -f2 | tr -d \"\,\v | awk '{$1=$1};1'`
wget https://releases.hashicorp.com/terraform/${TER_VER}/terraform_${TER_VER}_linux_amd64.zip
 
# Unzip
unzip terraform_${TER_VER}_linux_amd64.zip
sudo mv terraform /usr/local/bin/

• Display graph

export TF_VAR_rds_password=foobarbaz
terraform graph | dot -Tpng > infrastructure_graph.png

• Terraform destroy AWS ECS

terraform destroy -target=aws_ecs_service.backend -target=aws_ecs_task_definition.backend -target=module.vpc.aws_eip.nat -target=aws_lb.lb -target=aws_autoscaling_group.ecs-cluster

OpenTF

OpenTofu is an OSS tool for building, changing, and versioning infrastructure safely and efficiently. OpenTofu can manage existing and popular service providers as well as custom in-house solutions.

Commands

Format and Validate

Command	Description
terraform init	Prepare your working directory for other commands
terraform fmt	Reformat your configuration in the standard style
terraform validate	Check whether the configuration is valid

Plan and apply

Command	Description
terraform apply --auto-approve	Create or update infrastructure without confirmation prompt
terraform destroy --auto-approve	Destroy previously-created infrastructure without confirmation prompt
terraform plan -out plan.out	Output the deployment plan to plan.out
terraform apply plan.out	Use the plan.out to deploy infrastructure
terraform plan -destroy	Outputs a destroy plan
terraform apply -target=aws_instance.myinstance	Only apply/deploy changes to targeted resource
terraform apply -var myregion=us-east-1	Pass a variable via CLI while applying a configuration
terraform apply -lock=true	Lock the state file so it can’t be modified
terraform apply refresh=false	Do not reconcile state file with real-world resources
terraform apply --parallelism=5	Number of simultaneous resource operations
terraform refresh	Reconcile the state in Terraform state file with real-world resources
terraform providers	Get informatino about providers used in the current configuration

Workspaces

Command	Description
terraform workspace new <workspace>	Create a new workspace
terraform workspace select default	Change to a workspace
terraform workspace list	List all workspaces

State Manipulation

Command	Description
terraform state show aws_instance.myinstance	Show details stored in the Terraform state file
terraform state pull > terraform.tfstate	Output Terraform state to a file
terraform state mv aws_iam_role.my_ssm_role module.mymodule	Move a resource tracked via state to different module
terraform state replace-provider hashicorp/aws registry.custom.com/aws	Replace an existing provider with another
terraform state list	List all resources tracked in the Terraform state file
terraform state rm aws_instance.myinstance	Unmanage a resource, delete it from the Terraform state file

Import and Outputs

Command	Description
terraform import <resource_type>.<resource> <id>	Import a Resource
terraform output	List all outputs
terraform output <output>	List a specific output
terraform output -json	List all outputs in JSON format