Local state storage is the default method Terraform uses to store state information about your infrastructure. When you run Terraform commands, it creates a file called 'terraform.tfstate' in your working directory, which contains a JSON-formatted record of all resources Terraform manages.
The sta…Local state storage is the default method Terraform uses to store state information about your infrastructure. When you run Terraform commands, it creates a file called 'terraform.tfstate' in your working directory, which contains a JSON-formatted record of all resources Terraform manages.
The state file serves as Terraform's source of truth, mapping your configuration to real-world resources. It tracks resource IDs, metadata, and dependencies, enabling Terraform to determine what changes need to be applied during subsequent runs.
Key characteristics of local state storage include:
1. **Simplicity**: No additional configuration is required. Terraform automatically creates and manages the state file in your current directory.
2. **Single User Focus**: Local state works well for individual developers or learning environments where only one person manages the infrastructure.
3. **File-Based**: The state is stored as a plain text JSON file, making it readable but also requiring careful handling since it may contain sensitive information like passwords or API keys.
4. **No Locking**: Local state does not provide state locking by default, which can lead to conflicts if multiple users attempt concurrent operations.
5. **Backup Creation**: Terraform automatically creates a backup file called 'terraform.tfstate.backup' before modifying the state.
Limitations of local state storage:
- **Collaboration Challenges**: Team members cannot easily share state, leading to potential infrastructure drift or conflicts.
- **Security Concerns**: Sensitive data stored in plain text on local machines poses security risks.
- **No Remote Access**: The state is only available on the machine where it resides.
- **Risk of Data Loss**: If the local file is deleted or corrupted, recovery becomes difficult.
For production environments and team collaboration, migrating to remote state backends like Terraform Cloud, AWS S3, or Azure Blob Storage is strongly recommended to address these limitations.
Local State Storage in Terraform
What is Local State Storage?
Local state storage is the default method Terraform uses to store state files. When you run terraform apply, Terraform creates a file called terraform.tfstate in your current working directory. This file contains a JSON representation of all the resources Terraform manages, their current configurations, and metadata about your infrastructure.
Why is Local State Storage Important?
Understanding local state storage is fundamental because:
• It's the default behavior - no additional configuration is required • It serves as the foundation for understanding remote state concepts • It's suitable for individual developers and learning environments • It helps you understand how Terraform tracks infrastructure changes • The state file maps real-world resources to your configuration
How Local State Storage Works
1. Initialization: When you run terraform init, Terraform prepares the working directory
2. State Creation: After the first terraform apply, a terraform.tfstate file is created locally
3. State Updates: Each subsequent apply updates this local file with current resource states
4. Backup Files: Terraform automatically creates terraform.tfstate.backup before modifying the state
5. Plan Comparison: During terraform plan, Terraform compares the local state against actual infrastructure
Limitations of Local State Storage
• No collaboration support: Team members cannot share state easily • No state locking: Concurrent operations may corrupt the state • Security concerns: Sensitive data in state files stored on local disk • No versioning: Limited ability to recover from mistakes • Risk of data loss: Local file deletion means losing state information
When to Use Local State
• Learning and experimentation • Personal projects • Single-developer workflows • Quick prototyping • Development environments with no team collaboration needs
Key Commands Related to Local State
• terraform state list - Lists resources in the state • terraform state show - Shows details of a specific resource • terraform state pull - Outputs current state to stdout • terraform state mv - Moves items within state • terraform state rm - Removes items from state
Exam Tips: Answering Questions on Local State Storage
1. Remember the default: Local state is the DEFAULT backend - no backend configuration means local storage
2. Know the file names: The primary state file is terraform.tfstate and backup is terraform.tfstate.backup
3. Understand limitations: Questions often test knowledge about why local state is unsuitable for teams - focus on lack of locking and sharing capabilities
4. Sensitive data awareness: State files contain sensitive information in plain text - this is a common exam topic
5. Comparison questions: Be prepared to compare local state with remote backends - know the advantages of each
6. State file location: The state file is stored in the current working directory where Terraform commands are executed
7. JSON format: Remember that state files are stored in JSON format
8. Practice scenarios: If a question describes a solo developer learning Terraform, local state is often the appropriate answer
9. Migration context: Understand that you can migrate from local to remote state using backend configuration changes