A Workflow for Deploying Infrastructure Code with Terraform

We have looked at deploying application code, and now we will move on to infrastructure code. At first sight, the processes appear comparable, but infrastructure code presents unique issues that necessitate distinct techniques.

Terraform allows us to define, provision, and manage our infrastructure using a declarative manner. However, infrastructure code distribution differs from application code deployment, and grasping this distinction is critical for developing a dependable, automated procedure.

In this post, we will go over the normal procedure for delivering infrastructure code using Terraform, concentrating on things like version control, testing, deploying infrastructure, securing variables, integrating version control, and leveraging private registry. Throughout, we will contrast infrastructure code deployment with application code deployment, giving light on the distinct processes and activities involved.

Workflow for Deploying Infrastructure Code

1. Version Control: Managing Infrastructure as Code

   Just as application code uses version control to manage changes and assure cooperation, infrastructure code benefits from similar methods. Terraform stores your infrastructure code in configuration files, which describe cloud resources, networks, and other important components of your system. Keeping these files under version control (usually using Git repositories such as GitHub or GitLab) guarantees that any changes are tracked and auditable.

   Application Code vs. Infrastructure Code Deployment:
   When we think of application code deployment, it involves deploying the code itself—whether it’s a web app, backend service, or containerized service. This is often done with CI/CD tools like Jenkins, GitHub Actions, or GitLab CI. By contrast, infrastructure code deployment with Terraform revolves around provisioning cloud resources such as VPCs, databases, or EC2 instances, which can be done using commands like terraform apply.

   Branching:
   Deploying infrastructure code from separate branches can result in conflicts. For example, if one branch changes the instance type of an EC2 instance from t2.micro to t2.medium while another branch adds tags to the same instance, combining the two branches and deploying to the same environment may unintentionally override or interfere with crucial modifications. Terraform interprets infrastructure as a common real-world resource, and deploying several branches to the same resource can result in inconsistencies and unexpected behavior.

   • Avoid deploying from different branches to the same environment.

   • Use feature flags or separate environments to isolate changes until they’re ready to be merged.

2. Testing Infrastructure Code

   Before deploying infrastructure changes, it’s critical to validate them using tools like Terratest. This allows you to write automated tests that check if the infrastructure is provisioned correctly. Terraform’s built-in terraform validate and terraform plan commands are used to check the syntax and verify that the changes are valid before applying them.

   Application Code vs. Infrastructure Code Testing:
   Testing application code guarantees that particular pieces of the application function as intended—whether it is checking logic, ensuring API responses are right, or validating UI behaviors. In contrast, infrastructure code tests guarantee that resources like as databases, load balancers, and virtual machines are correctly setup and provided.

   • Use Terratest to validate infrastructure and ensure that cloud resources, networks, and other configurations are correctly applied.

   • Leverage CI/CD pipelines to automatically trigger infrastructure testing before applying changes to production environments.

3. Deploying Infrastructure Code: Automation is Key

   Once your infrastructure code has been tested, it is time to deploy it. This method can be easily automated using Terraform's command-line interface (CLI). Terraform apply interacts with the cloud provider's API to build, change, or delete resources defined in the configuration files.

   How Infrastructure Code Deployment Works:

   • Plan: Before making any changes, Terraform will generate a plan to show what changes will be made.

   • Apply: Once reviewed, the changes are applied to the cloud provider.

   • State Management: Terraform keeps track of the state of your infrastructure. Any modifications are made incrementally, based on the state file, ensuring consistency.

Application Code vs. Infrastructure Code Deployment:
Changes are pushed to the application environment, which can be a container, a virtual machine, or a serverless function. However, infrastructure code deployment entails making modifications to the underlying infrastructure that serves the application. For example, while an application code deployment may include pushing a new version of your web service to a Kubernetes cluster, infrastructure code deployment may entail creating a new VPC or configuring security groups.

4. Securing Variables: Protecting Sensitive Data in Infrastructure Code

   Security is vital in any context, but when dealing with infrastructure, the necessity to secure sensitive data like API keys, database credentials, and other critical information becomes much more urgent. Terraform has numerous methods for handling sensitive variables safely.
   Terraform allows you to mark variables as sensitive, ensuring that their values do not show up in logs or output. You can also use tools like AWS Secrets Manager, Azure Key Vault, or HashiCorp Vault to securely manage and retrieve secrets at runtime.

   Application Code vs. Infrastructure Code Security:
   While application code often relies on secure secrets management for things like API keys and service credentials, infrastructure code security ensures that the actual infrastructure configurations themselves—such as SSH keys, access credentials, and network configurations—are protected from exposure during provisioning.

5. Integrating Version Control and Deployment Pipelines

   Integrating version control systems into CI/CD pipelines is crucial for automating infrastructure installations. You can use tools like GitHub Actions or GitLab CI to link your Git repositories and automatically deploy Terraform depending on changes to your infrastructure code.

   Infrastructure Code vs. Application Code Deployment Pipelines:
   In infrastructure code deployment, the focus is on provisioning cloud resources. The pipeline can be configured to trigger Terraform plans and applies based on specific Git events, like pushes to a main branch. For application code deployment, the pipeline typically automates the build, test, and deployment of new versions of the application code.

6. Private Registries in Terraform: Managing Custom Modules

   Terraform modules let you reuse code across several projects and teams. Using private registries, you may handle custom Terraform modules privately, ensuring consistency across all environments.

   Custom Terraform modules, such as those used to provision network resources, storage solutions, or security configurations, can be saved in a private registry and reused across numerous Terraform projects, eliminating duplication and ensuring best practices are followed.

   Conclusion

   Terraform provides a robust, automated solution to manage your cloud resources, assuring consistency, repeatability, and security. Understanding the difference between infrastructure code and application code deployments allows you to develop efficient workflows that prioritize provisioning, testing, and securing infrastructure while keeping application deployments clean and separate.

   In this post, we looked at the normal approach for deploying infrastructure code using Terraform, from version control to testing, deployment, and security. The next time you deploy infrastructure, keep in mind that it requires a different set of processes and tools than application code deployment—but both are necessary for your services to run well.