What’s the Difference Between Terraform and Kubernetes?
Terraform and Kubernetes are DevOps tools used in application deployment and lifecycle management. However, they both perform different functions. Terraform is an Infrastructure as Code (IaC) tool developers use to automatically create, provision, and manage cloud IT resources. With it, you can focus on what you need from your cloud infrastructure and automatically handles the steps necessary for the setup. In contrast, Kubernetes is a container orchestration tool that helps you manage your containers at scale. It manages resource provisioning, container scheduling, grouping, and other coordination tasks.
Why are Kubernetes and Terraform used?
Both Kubernetes and Terraform help deploy and manage cloud applications at scale.
Terraform
An IT environment typically requires multiple infrastructure resources, components, and configurations. The following factors can further complicate infrastructure provisioning:
- Different teams within an organization may require similar infrastructure but with small configuration changes.
- Infrastructure may be distributed between on-premises settings and multiple cloud providers.
- Application changes may require you to modify or upgrade existing infrastructure.
You can provision infrastructure components manually, one at a time. However, it can become difficult and time-consuming, especially if you have many complex resources. Terraform solves this challenge by helping you provision and support your managed infrastructure using code. Infrastructure as code brings repeatability, transparency, and efficiency to managed infrastructure.
Kubernetes
Modern applications are made of microservices—independent components that run each application process as a service. Each service performs a single function and communicates with other services through a well-defined interface called an API. Containers pack microservices as deployable programs on different platforms. However, some applications can scale to thousands of microservices across different server instances. Multi-container applications introduce new management challenges:
- How should you coordinate multiple containers?
- How should you schedule containers?
- How should you group and catalog containers?
Kubernetes handles such operating complexities so you can scale your workloads and manage container deployment across multiple server instances. You can run your containerized applications anywhere without changing your operational tooling.
How they work: Terraform compared with Kubernetes
Before we look at the similarities and differences, let's briefly explore the core concepts of each technology.
Kubernetes
Kubernetes works by managing a cluster of server instances and scheduling containers to run on the cluster. It meets the resource requirements of each container by managing compute resources efficiently. Containers are run in logical groupings called pods, and you can run and scale one or many containers together as a pod.
Kubernetes components, like the control plane software, decide when and where to run your pods, manage traffic routing, and scale your pods based on utilization or other metrics that you define. Each pod is given an IP address and a single DNS name, which Kubernetes uses to connect your services with each other and external traffic.
Terraform
Terraform uses state files to store information about your infrastructure components. The state file maps infrastructure code to real-world resources. The Terraform Core is the key component that takes two Terraform files as input variables:
- Your existing resources—or the current state file.
- Your desired state for those resources—or the configuration file.
With this information, the Terraform Core creates a resource graph that identifies any resource interdependencies and plans what resources it needs to add, modify, or remove. After you approve the plan, the Core communicates with third-party services for creating and provisioning infrastructure components.
What are the similarities between Terraform and Kubernetes?
There are similarities in how both tools work and how you use them.
Declarative configuration
Both tools use a declarative approach to define and manage resources. A declarative configuration is an approach to defining and managing the desired state of a system or application without specifying the step-by-step instructions for achieving that state. Instead of describing the exact sequence of operations to perform, declarative configuration focuses on describing the end result or the system's desired state. With both tools, you can express what you want your system to look like or how it should behave. The tools handle the necessary steps to reach that state.
Automatic change management
Both Kubernetes and Terraform provide mechanisms to automate infrastructure change management. They can automatically detect complex changes in your configurations and apply them to your infrastructure while managing dependencies. They support version control, reproducibility, and collaboration mechanisms, treating the definition of cloud environments as code artifacts. Changes are managed incrementally to reduce errors, as well as to support continuous integration and deployment pipelines.
Multi-cloud deployment
Terraform and Kubernetes are cloud-agnostic and support multiple cloud providers. They can manage infrastructure resources hosted across multiple cloud platforms or on-premises environments, allowing you to choose the most appropriate resources for your applications.
Community support
Both Terraform and Kubernetes are open source with active developer communities. They offer various plugins, extensions, and integrations that improve functionality and allow integration with other tools and services. The communities behind these projects provide documentation, tutorials, and support, helping developers adopt and use these tools effectively.
Key differences: Terraform compared with Kubernetes
Terraform and Kubernetes are two distinct tools with different purposes and scopes within cloud computing and infrastructure management.
Infrastructure provisioning
Both Terraform and Kubernetes provision infrastructure, but at different levels. Terraform provides and manages resources such as virtual machines or cloud instances, networks, storage, and other components in your cloud environment. Alternately, Kubernetes provisions infrastructure for container workloads only.
Level of abstraction
Terraform operates at a higher level of abstraction, managing resources and their configurations across cloud environments. Kubernetes operates at a lower level of abstraction, focusing on the deployment and lifecycle of containers within a cluster. It provides features for load balancing, networking, service discovery, and scaling of containers.
Configuration language
Terraform uses a domain-specific language called HashiCorp Configuration Language (HCL), or JSON for Terraform v0.12 and earlier. Developers write declarative configuration files in HCL. In contrast, they use YAML or JSON-based manifest files to define and configure Kubernetes clusters pods, services, deployments, and other resources.
Failure recovery
Terraform does not provide automatic failure recovery. You must write scripts and run them in case of failure so Terraform can restore the infrastructure. In contrast, Kubernetes can automatically detect and restart failed containers to maintain the desired state of the application. You must use additional Terraform tools to implement failure recovery with Terraform.
Ease of use
In terms of ease of use and getting started, Terraform is considered easier for beginners compared to Kubernetes. Setup and installation are straightforward, and HCL is intuitive to learn and work with. You can easily manage cloud infrastructure in different environments with a unified workflow.
Kubernetes has a steeper learning curve as you have to understand how to deploy Kubernetes clusters. It involves configuring the primary and worker nodes, installing the necessary components, and ensuring proper communication among them. The setup process is more involved and requires more knowledge that just the infrastructure environments. It requires knowledge of containerization principles, networking, load balancing, and scaling strategies.
When to use: Terraform compared with Kubernetes
You can use Terraform to support infrastructure for multi-tier applications that scale up or down frequently to meet demand. Developers use preconfigured Terraform templates to set up coding environments quickly with minimal support from the operations team. Network engineers use Terraform to deploy infrastructure like firewalls and routers in the cloud. You can use Terraform to create and deploy new, disposable environments and then discard them after they are used.
Use Kubernetes to manage containerized applications at scale. For example, to move seamlessly from local development machines to production deployments or to run highly available and scalable Kubernetes clusters on AWS while maintaining full compatibility with deployments running on-premises.
Summary of differences: Terraform compared with Kubernetes
| Terraform |
Kubernetes |
|
| What is it? |
Infrastructure-as-code tool |
Container orchestration tool |
| Why is it used? |
To bring repeatability, transparency, and efficiency to managed infrastructure |
To reduce operating complexities so you can scale your container workloads and multicontainer applications |
| Resource management |
Manages all types of infrastructure objects like compute instances, storage, and networking |
Only manages server resources as a Kubernetes cluster for container workloads |
| Abstraction |
Abstracts infrastructure provisioning across multiple cloud environments |
Abstracts server provisioning within a single cluster |
| Configuration language |
HCL |
YAML or JSON |
| Failure recovery |
You must use tools and scripts to manage failure recovery |
Automated and self-managed |
| Ease of use |
Smaller learning curve, easier to get started |
Requires knowledge of containerization principles, networking, load balancing, and scaling strategies before you can get started |
How can AWS help with your Terraform and Kubernetes requirements?
AWS Terraform modules are the building blocks for Terraform-managed resources on AWS. Modules are published under an open-source license and developed by AWS in partnership with HashiCorp. Instead of Terraform, you can also consider using the AWS Cloud Development Kit (AWS CDK), an open-source software development framework. With AWS CDK you can:
- Define your cloud application resources with familiar programming languages including Terraform HCL state files.
- Accelerate your onboarding to AWS because it doesn't require you to learn as many new things.
Similarly, Amazon Elastic Kubernetes Service (Amazon EKS) is a managed Kubernetes service to run Kubernetes in the AWS Cloud and on-premises data centers. In the cloud, Amazon EKS automatically manages the availability and scalability of Kubernetes resources for scheduling containers, managing application availability, storing cluster data, and other key tasks.
Instead of Kubernetes, you can also use Amazon Elastic Container Service (Amazon ECS), a fully-managed container orchestration service to deploy, manage, and scale containerized applications on the AWS cloud platform. With Amazon ECS you can:
- Describe your application and the resources required.
- Launch, monitor, and scale your application across flexible compute options with automatic integrations to other supporting AWS services.
- Perform system operations such as creating custom scaling and capacity rules, as well as observe and query data from application logs and telemetry.
Get started with Terraform and Kubernetes on AWS by creating an account today.
