Infrastructure as Code
By21 Oct 2022
Infrastructure management is a core requirement for most modern applications. More and more infrastructure modifications are required to facilitate the proper functioning of the software.
It is impossible to keep up with the fast development cycles with manual infrastructure management. It will create bottlenecks causing delivery delays.
IaC, or Infrastructures as Code, has become the solution to this issue – allowing users to align infrastructure with development. It also facilitates faster automated repeatable changes by codifying all the infrastructure and configuration and managing them through the delivery pipeline.
To put it simply, IaC enables users to codify their infrastructure by following:
● Create repeatable version-controlled configurations
● Integrate them as a part of the CI/CD pipeline
● Automate the infrastructure management
There is one other very important reason why we should use IaC: it makes developers happy. IaC offers a better alternative that allows computers to do what they do best (automation) and developers to do what they do best (coding).
So, what is Terraform, and how can it be used to manage infrastructure at scale?
Terraform is a cross-platform IaC from HashiCorp, an open-source tool, that allows you to define the infrastructure for a variety of cloud providers (e.g. AWS, Azure, Google Cloud, DigitalOcean, etc) using a simple, declarative programming language and deploy and manage that infrastructure using a few CLI commands.
Being a cross-platform tool, Terraform can be used across any supported platform. It accomplishes this by interacting with the APIs of cloud providers.
The Terraform workflow is one of the simplest workflows consisting of three steps to manage any type of infrastructure, providing the user flexibility to change the workflow to support their exact needs.
The 1st step – Writing is where the users create the configurations to define or modify the underlying resources.
The 2nd step – Planning is where Terraform will look at the configuration files and create an execution plan, enabling users to see the exact charges that will happen to the underlying infrastructure from what new resources are getting created, resources, modified, and deleted.
The 3rd step – Applying happens when the plan is satisfactory once the user has confirmed the changes. Terraform will carry out the changes to achieve the desired state in a specific order respecting all the resource dependencies. Terraform will automatically identify the resource dependencies of the platform and execute the changes without causing issues. It keeps track of all the changes to the infrastructure and detects configuration drifts by using the state. This state can be stored locally or in a remote-backed system, such as an s3 bucket. It always references this state file to identify the resources it manages and keep track of the changes to the infrastructure.
Summary of benefits of Terraform
Declarative. A declarative tool allows users to specify the end state and the IaC tools will automatically carry out the necessary steps to achieve the user configuration.
Cross-platform. Unlike AWS CloudFormation and Azure resources, being platform-specific, Terraform allows users to utilize a single instrument to manage infrastructure across platforms with applications using many tools, platforms, and multi-cloud architectures.
Reusable. Terraform encourages the creation of reusable configurations where users can utilize the same configuration to provision multiple environments. Plus, Terraform allows the creation of reusable components within the configuration files with modules.
Managed state. With state files keeping track of all the changes in the environment, all modifications are recorded and any unnecessary changes will not occur unless explicitly specified by the user. It can be further automated to detect any config drifts and automatically fix them.
Easy rollbacks. As all configurations are version controlled and the state is managed, users can easily and safely roll back most infrastructure configurations without further reconfigurations.
Integration to continuous integration and continuous deployment. Terraform provides a simple three-step workflow that can be easily integrated into any CI/CD pipeline, helping to completely automate infrastructure management.
How to use Terraform
Using Terraform can be started by simply installing it in a local environment. Terraform supports Windows, Linux, and macOS environments. It provides users with the option to install manually using a pre-compiled binary, or use a package manager (Homebrew on Mac, Chocolatey on Windows, Apt/Yum on Linux). Terraform offers users the flexibility to be installed in their environments and integrate into their workflows.
HashiCorp also provides Terraform Cloud, which provides users with a platform to manage infrastructure on all supported providers without the need of installing Terraform itself. Terraform Cloud consists of the following features:
● Remote encrypted state storage
● Direct CI/CD integrations
● Fully remote and SOC2-compliant collaborative environment
● Version Controls
● Private Registry to store modules and Policies as Code support to configure security and compliance policies
● Complete auditable environment.
● Cost estimations before applying infrastructure changes in supported providers.
Terraform Cloud is integrated with other HasiCorp Cloud Platform services such as Vault, Consul, and Packer to manage secrets, provide service mesh and create images.
To summarize, Terraform is a powerful IaC tool aiming to provide the best balance between user-friendliness and features. It is declarative and cross-platform, therefore allowing it to be used in any supported environment. The flexible workflow and configuration options of Terraform allow it to be run in local environments. Users are free to select the exact implementation suited for their needs to manage Terraform Cloud solutions, making it one of the leading IaC tools.