Challenges with Infrastructure as Code: Extending Terraform functionality
6 min read
Terraform is a popular tool for managing infrastructure as code, which allows you to define, provision, and update your cloud resources using a declarative language. Terraform supports over 100 providers, including major public and private clouds.
However, working with Terraform is not without challenges, especially when it comes to collaboration, scalability, and maintainability. Let's explore some of the common problems that Terraform users face and discuss some solutions for them. Let's first take a look at some of the challenges.
Challenges with using Terraform
Terraform users encounter various challenges when they use Terraform to manage their infrastructure as code. Some of these challenges are:
Code duplication: Terraform code can become repetitive and verbose when you have to define similar resources or configurations for different environments or regions. For example, you may have to create multiple VMs, subnets, security groups, and instances for your dev, test, and prod environments.
This can lead to code duplication and inconsistency, which can make your code hard to read, maintain, and update. You also need to manage multiple variables and outputs for each environment or region.
Code generation: Terraform code can also become complex and cumbersome when you have to deal with dynamic or conditional configurations. For example, you may want to create different resources or settings based on some input parameters or logic.
Terraform does not support interpolation or expressions in some code sections where you may need them. For instance, you cannot use variables or functions in resource names or count attributes. You also cannot use loops or conditionals in resource blocks. You need to resort to workarounds such as using null resources or external data sources.
Orchestration: Terraform code can also become challenging to orchestrate and execute when you have multiple stacks or modules that depend on each other or need to be run in a specific order.
For example, you may want to create a network stack before creating a compute stack that depends on it. Or you may want to run some commands before or after applying your Terraform code. Terraform does not provide a built-in way to orchestrate or automate the execution of multiple stacks or modules. You need to use external tools such as Makefiles or shell scripts.
To address these challenges, we need a solution that can simplify and automate state management, support existing infrastructure, reduce code duplication, enable code generation, and provide orchestration.
Let's take a look at Terramate, one of the possible solutions to address the above limitations of Terraform.
Introduction to Terramate
Terramate is an open-source code generator and orchestrator for Terraform that adds powerful capabilities such as code generation, stacks, orchestration, change detection, data sharing, and more to Terraform. Terramate helps implement and maintain highly scalable Terraform projects by integrating with existing tooling in a non-intrusive way without major lock-ins and for a broader audience.
Terramate introduces the concept of stacks, which are directories that contain Terraform code and state. Stacks are organized in a hierarchical structure based on the filesystem, which allows Terramate to infer dependencies and run commands on multiple stacks at once. Stacks can allow you to split up monolithic states into smaller and isolated units to enable shorter CI/CD runtimes, lower the blast radius, enable parallelization and allow better collaboration
Terramate also allows you to generate Terraform code from templates or data sources in each stack. You can also share data across stacks or export data to other tools.
Terramate also provides a powerful orchestration engine that can run Terraform commands on your stacks based on changes detected by Terramate. You can also run custom scripts before or after Terramate commands.
Benefits of using Terramate
Using Terramate can bring you many benefits for managing your infrastructure as code projects. Some of these benefits include:
You can split your Terraform code into smaller and isolated units, which can increase the change frequency, reduce the blast radius, provide clear ownership, and improve collaboration. For example, you can create a stack for each environment, region, or service, and manage them independently. You can also use Terramate to run commands on specific stacks or groups of stacks based on your needs.
You can build custom delivery workflows on top of a powerful orchestration and execution engine. For example, you can use Terramate to run Terraform commands on your stacks based on changes detected by Terramate. You can also use Terramate to run custom scripts before or after Terramate commands. You can also use Terramate to integrate with other tools such as Infracost, Kubernetes, Checkov, and more.
You can speed up execution run times by using change detection, which only runs commands in stacks that have been modified in the current branch or since the last merge. For example, you can use Terramate to run Terraform commands only on the stacks that have changed since the last commit or pull request. This can save you time and resources by avoiding unnecessary operations.
You can provide powerful templates and abstraction layers to enable developers to deploy complex infrastructure without knowing the details of Terraform. For example, you can use Terramate to generate Terraform code from templates or data sources in each stack. You can also use Terramate to share data across stacks or export data to other tools. This can help you keep your code DRY and consistent, and reduce the learning curve for Terraform.
You can reduce the maintenance overhead by automatically generating and updating Terraform configuration, provider definitions, backend configuration, and more. For example, you can use Terramate to generate Terraform configuration files such as
terraform.tfandversions.tffrom templates or data sources in each stack. You can also use Terramate to update provider versions or backend settings automatically.You can overcome some of the limitations of Terraform by allowing interpolation in code sections where Terraform does not support dynamic configurations. For example, you can use Terramate to interpolate variables or functions in resource names or count attributes. You can also use Terramate to use loops or conditionals in resource blocks.
These are some of the benefits of using Terramate for managing your infrastructure as code projects. Terramate can help you simplify and automate your Terraform workflows, reduce code duplication and complexity, enable code generation and data sharing, and provide orchestration and integration with other tools.
Conclusion
Terramate can solve some of the common Terraform challenges such as state management, existing infrastructure, code duplication, code generation, and orchestration. It is a great solution for managing your infrastructure as code with Terraform.
It can help you simplify and automate your Terraform workflows, reduce code duplication and complexity, enable code generation and data sharing, and provide orchestration and integration with other tools. If you are looking for a way to make your Terraform projects more scalable, maintainable, and collaborative, give Terramate a try.