This is a guide for developers on best practices when working with Terraform scripts and Files.com. This guide integrates our internal recommendations with industry-standard practices to help you manage infrastructure changes efficiently and safely.

By following these best practices, you can manage your infrastructure with greater confidence and efficiency. Testing changes in isolated environments, maintaining version-controlled configurations, and adhering to security and formatting standards are key steps in achieving reliable and maintainable infrastructure deployments.

About Terraform

Terraform is a powerful Infrastructure as Code (IaC) tool that allows you to define and provision infrastructure using declarative configuration files.

At Files.com, we leverage Terraform to manage our infrastructure consistently and predictably.

This guide outlines best practices to follow when developing and deploying Terraform scripts, ensuring smooth collaboration and minimizing risks.

Maintain Terraform as the Single Source of Truth

Terraform operates most effectively when it is the exclusive tool managing your infrastructure resources. This principle ensures that Terraform has complete knowledge of the current state of your infrastructure, allowing it to plan and apply changes accurately.

Introducing other tools or manual processes to manage the same resources can lead to conflicts and unpredictable behavior. For instance, if you use Terraform to manage user accounts in your Files.com site, integrating another provisioning system like SCIM to handle users concurrently can cause discrepancies. Terraform may not recognize changes made outside its purview, leading to potential overwrites or deletions during subsequent apply operations.

To prevent such issues, it's essential to designate Terraform as the sole manager of specific resources. If you need to bring existing resources under Terraform's management, use the terraform import command to incorporate them into your state file. This approach ensures that Terraform is aware of all resources it manages, maintaining consistency and preventing unintended modifications.

By adhering to this practice, you uphold the integrity of your infrastructure management process, reduce the risk of configuration drift, and ensure that changes are predictable and controlled.

Preserve Current State Before Making Changes

Before implementing any changes, it's crucial to capture the current state of your infrastructure.

This practice provides a safety net, allowing you to roll back to a known good configuration if needed.

Use the terraform state pull command to export the current state and store it securely.

This exported state serves as a reference point and can be invaluable during troubleshooting or rollback scenarios.

Utilize Child Sites for Development and Testing

To avoid unintended impacts on your production environment, conduct development and testing in isolated environments.

Files.com provides the use of child sites, which are ideal for this purpose. By applying changes to a child site first, you can validate the effects in a controlled setting.

This approach aligns with the principle of testing in environments that mirror production as closely as possible, reducing the likelihood of surprises during deployment.

Implement and Test Incremental Changes

When making changes to your Terraform configurations, adopt an incremental approach.

Modify your exported state or configuration files to reflect the desired changes, and then apply these changes to your child site.

After each change, thoroughly test to ensure it behaves as expected.

This iterative process helps identify issues early and simplifies troubleshooting.

Repeat this cycle of modification and testing until you're confident in the changes.

Apply Changes to Production with Confidence

Once you've validated your changes in the child site environment, you're ready to apply them to the production environment.

Before doing so, ensure that:

• All changes have been committed to version control.
• The production environment's state is up to date.
• You've reviewed the planned changes using terraform plan.

Applying changes with this level of preparation minimizes the risk of unexpected issues in production.

Additional Best Practices

Version Control and Collaboration

Store your Terraform configurations in a version control system like Git.

This practice facilitates collaboration, change tracking, and rollback capabilities. Implement code reviews to maintain code quality and share knowledge among team members.

Use Remote State Storage

Configure remote state storage to manage your Terraform state files securely and enable collaboration.

Remote backends like AWS S3, Azure Blob Storage, or Terraform Cloud provide state locking and versioning features, preventing conflicts and data loss.

Modularize Your Configuration

Break down your Terraform configurations into reusable modules.

Modularization promotes code reuse, simplifies maintenance, and enhances readability. Define clear interfaces for your modules using input variables and outputs.

Secure Sensitive Data

Avoid hardcoding sensitive information like API keys or passwords in your Terraform files.

Instead, use environment variables or secret management tools like HashiCorp Vault to inject sensitive data at runtime.

Validate and Format Code

Regularly use terraform validate to check the syntax and internal consistency of your configurations.

Employ terraform fmt to format your code according to standard conventions, improving readability and reducing diffs in version control.

More Information

For more information on using Terraform with Files.com, refer to our Terraform documentation.