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Atmos Components

When you design cloud architectures with Atmos, you start by breaking them apart into pieces called components. Then, you implement Terraform "root modules" for each of those components, and compose them with Stack configurations.

The most common use-case for Atmos is using implementing components using Terraform "root modules". But since Atmos was designed to be tool-agnostic, custom commands can be used to implement components for any type of tooling.

Components can be as small as you'd like (but we don't recommend too small), or as large as a Terralith (but we don't recommend that either). See our best practices for components to get a sense of what we recommend.


Typical components of an architecture are things like VPCs, clusters, databases, buckets, load balancers, and applications. Implement components using Terraform "root" modules.


Components offer a multitude of applications across various business scenarios. Cloud Posse publishes its AWS components for free, so you can see some technical use-cases for Terraform components.

  • Accelerate Development Cycles: By reusing components, development teams can significantly shorten the time from concept to deployment, facilitating faster product iterations and quicker responses to market changes.

  • Security policies and compliance controls DevOps and SecOps teams implement components to uniformly apply security policies and compliance controls across all cloud environments, ensuring regulatory adherence.

  • Enhance Collaboration Across Teams: Components foster a shared understanding and approach to infrastructure, promoting collaboration between development, operations, and security teams, leading to more cohesive and secure product development.

Flavors of Components

Atmos natively supports two kinds of components, but using custom commands, the CLI can be extended to support anything (e.g. docker, packer, ansible, etc.)

  1. Terraform: These are stand-alone "root modules" that implement some piece of your infrastructure. For example, typical components might be an EKS cluster, RDS cluster, EFS filesystem, S3 bucket, DynamoDB table, etc. You can find the full library of SweetOps Terraform components on GitHub. By convention, we store components in the components/terraform/ directory within the infrastructure repository.

  2. Helmfiles: These are stand-alone applications deployed using helmfile to Kubernetes. For example, typical helmfiles might deploy the DataDog agent, cert-manager controller, nginx-ingress controller, etc. By convention, we store these types of components in the components/helmfile/ directory within the infrastructure repository.

Terraform Components

One important distinction about components that is worth noting about Terraform components is they should be opinionated Terraform "root" modules that typically call other child modules. Components are the building blocks of your infrastructure. This is where you define all the business logic for provisioning some common piece of infrastructure like ECR repos (with the ecr component) or EKS clusters (with the eks/cluster component). Our convention is to stick Terraform components in the components/terraform/ directory.