Terraform: Commands & State Management

Core Commands

terraform init: Initializes a working directory containing Terraform configuration files. Downloads required providers and configures the backend.
```
  terraform init
```
terraform plan: Generates an execution plan showing proposed infrastructure changes.
```
  terraform plan
```
terraform apply: Applies changes to reach the desired infrastructure state. Use -auto-approve to skip confirmation.
```
  terraform apply  # Interactive mode
  terraform apply -auto-approve  # Skip prompt
```

terraform destroy: Destroys all managed infrastructure. Use with caution!

  terraform destroy  # Interactive mode
  terraform destroy -auto-approve  # Skip prompt

terraform validate: Checks configuration files for syntax and consistency.
```
  terraform validate
```
terraform fmt: Rewrites configuration files to a standardized format.
```
  terraform fmt
```
terraform show: Displays the current state or a saved plan in readable format.
```
  terraform show
```
terraform output: Prints output values from the state file.
```
  terraform output
```
terraform refresh: Syncs the state file with real-world infrastructure (rarely used directly).
```
  terraform refresh
```

terraform state list: Lists resources tracked in the state.
```
  terraform state list
```
terraform state show <resource>: Displays details of a specific resource. Replace <resource> with the resource address.
```
  terraform state show aws_instance.web
```
terraform state pull: Outputs the raw state data.
```
  terraform state pull > state.json
```
terraform state push: Overwrites remote state with a local state file (use with caution).
```
  terraform state push terraform.tfstate
```
terraform state mv: Moves a resource within the state (useful for refactoring).
```
  terraform state mv aws_instance.old aws_instance.new
```
terraform state rm: Removes a resource from the state (does not destroy the resource).
```
  terraform state rm aws_instance.web
```
terraform import <resource> <id>: Imports existing infrastructure into the state.
```
  terraform import aws_instance.web i-1234567890abcdef0
```

terraform workspace new <name>: Creates a new workspace.
```
  terraform workspace new dev
```
terraform workspace select <name>: Switches to a workspace.
```
  terraform workspace select prod
```
terraform workspace list: Lists all workspaces.
```
  terraform workspace list
```
terraform workspace delete <name>: Deletes a workspace.
```
  terraform workspace delete staging
```

terraform version: Shows Terraform and provider versions.
```
  terraform version
```
terraform get: Downloads and updates modules.
```
  terraform get
```
terraform graph: Generates a visual dependency graph.
```
  terraform graph | dot -Tsvg > graph.svg
```
terraform taint <resource>: Forces recreation of a resource on the next apply.
```
  terraform taint aws_instance.web
```
terraform untaint <resource>: Removes taint from a resource.
```
  terraform untaint aws_instance.web
```

terraform force-unlock <lock-id>: Manually releases a stuck state lock.
```
  terraform force-unlock 3a0d98d0-0d1a-2345-6789-abc123def456
```
terraform console: Launches an interactive console for testing expressions.
```
  terraform console
```
terraform providers: Displays provider configurations.
```
  terraform providers
```

terraform state replace-provider: Updates the provider in the state file.

  terraform state replace-provider hashicorp/aws registry.acme.corp/acme/aws

TF_LOG: Sets logging verbosity (e.g., TRACE, DEBUG, INFO).
```
  export TF_LOG=DEBUG
```
TF_VAR_<variable_name>: Sets a Terraform variable via the environment.
```
  export TF_VAR_region="us-west-2"
```
TF_CLI_ARGS: Passes global CLI arguments.
```
  export TF_CLI_ARGS="-input=false"
```
TF_IN_AUTOMATION: Suppresses prompts in CI/CD environments.
```
  export TF_IN_AUTOMATION=true
```

Note: Always review Terraform plans carefully before applying changes. Use destructive commands like destroy and state push with caution.

Terraform Official Documentation
https://developer.hashicorp.com/terraform/docs
This is the official documentation for Terraform, covering how to install, configure, use commands, and follow best practices.
Terraform CLI Commands Reference
https://developer.hashicorp.com/terraform/cli/commands
A detailed guide to all Terraform CLI commands, including descriptions, flags, and examples.
Terraform State Management
https://developer.hashicorp.com/terraform/language/state
The official guide for managing state files in Terraform, with commands for listing, importing, and modifying state.
Terraform Workspaces
https://developer.hashicorp.com/terraform/cloud-docs/workspaces
An in-depth guide on using Terraform workspaces to manage multiple environments.
Terraform Environment Variables
https://developer.hashicorp.com/terraform/cli/config/environment-variables
A comprehensive list of environment variables supported by Terraform, including usage examples.