Overview

A repo to demo the different Terraform CLI commands

Demo

Code walk-through

1. main.tf
2. variables.rf
3. terraform.tfvars
4. outputs.tf

terraform init command

1. Lock file creation
2. tree structure with .terraform folder with providers and modules
3. The -upgrade flag. Upgrade the kreuzwerker/docker provider to 3.0.1

terraform validate command

1. Show a successful output
2. Comment out the docker_image resource in main.tf to show a failed output

terraform plan command

1. Show the changes that are about to happen
2. Discuss the -out flag

terraform apply command

1. Show the plan and the prompt
2. Show the NGINX welcome page
3. Run docker ps
4. Talk about the -auto-approve flag
5. Show the state file created

terraform destroy command

1. Show the plan and the prompt
2. Discuss the -auto-approve flag
3. Discuss the alternative to run terraform apply -destroy
4. Show the state file

terraform console command

1. First show the terraform state list command
2. Try these commands:
   • var.image_name
   • "${var.image_name}:${var.image_tag}"
   • docker_image.nginx_image

terraform fmt command

1. Break the formatting in some of the files and run the command

terraform taint command

1. Run: terraform taint docker_container.nginx_container
2. Warning: This command is deprecated. The recommendation is to use the -replace option with terraform plan and apply instead. Using the -replace option gives you more visibility into the impact of the change before you apply it. With taint, you risk having another person run a new plan on your tainted object without your knowledge of the outcomes.
3. Run terraform plan -replace docker_container.nginx_container
4. Run terraform apply -replace docker_container.nginx_container

terraform workspace commands

1. The terraform workspace command is used to manage workspaces. Workspaces are named containers for Terraform state that allow you to isolate and switch between different configurations and environments.
2. Run terraform workspace list
3. Run terraform workspace new dev
4. Run terraform workspace new prod
5. Run terraform workspace list
6. Make sure no containers exist otherwise run terraform destroy
7. Run the following:

terraform workspace select dev
terraform init
terraform apply -auto-approve
terraform workspace select prod
terraform init
terraform apply -auto-approve

8. Notice the file structure
9. Run docker ps to see the container names and the external ports