Atlantis

Atlantis is an open-source self-hosted application that automates Terraform pull request workflows by running Terraform plans and applies in response to version-control events and pull request comments (infrastructure automation / GitOps for Infrastructure-as-Code (IaC)).

• Automated Terraform plan and apply execution triggered from pull requests and comments (infrastructure automation).
• Integration with Git-based platforms such as GitHub, GitLab, Bitbucket, and Azure DevOps (version control integration).
• Server that listens for webhooks and posts Terraform plans back to pull requests for review (collaboration workflow).
• Policy and safety controls including per-project configuration, approvals, and locking to avoid concurrent Terraform runs (governance and concurrency control).
• Support for multi-repo and multi-environment Terraform workflows through configuration files stored alongside code (environment and workflow management).

More About Atlantis

Atlantis is an open-source tool that connects Terraform-based IaC workflows with pull request processes in Git hosting platforms, enabling teams to manage infrastructure changes through the same review and approval mechanisms used for application code (infrastructure automation / GitOps). It addresses the problem of coordinating Terraform plan and apply operations across multiple engineers and repositories while keeping a single source of truth in version control systems.

The core Atlantis server receives webhook events from supported Git platforms (version control integration) such as GitHub, GitLab, Bitbucket, and Azure DevOps. When a pull request that modifies Terraform configuration is opened or updated, Atlantis can automatically run terraform plan and post the output as a comment on the pull request (infrastructure automation). This process lets reviewers see the proposed infrastructure changes inline with code review, without requiring each engineer to run Terraform locally.

Atlantis supports a comment-driven workflow, where predefined commands such as atlantis plan and atlantis apply are issued as pull request comments (collaboration workflow). The server interprets these commands, executes Terraform in a controlled environment, and updates the pull request with status and logs. This approach keeps an auditable record of who triggered each plan or apply and under which code revision it Radio Access Network (RAN) (governance and compliance).

Configuration for Atlantis is defined via server-side configuration and per-repository atlantis.yaml files (configuration management). These configurations specify Terraform projects, working directories, workflows, and custom commands, and they allow teams to manage multiple workspaces, modules, and environments across many repositories (environment and workflow management). Locking features help ensure that only one Terraform apply runs at a time per project to avoid state conflicts, and policies can require approvals or restrict who can run apply commands (governance and concurrency control).

In enterprise and institutional environments, Atlantis is typically deployed as a self-hosted service, often running in containers or Kubernetes, and integrated with existing Continuous Integration and Continuous Deployment (CI/CD) pipelines and Git-based workflows (platform integration). It fits within IaC practices by ensuring that all Terraform changes pass through version-controlled pull requests, review, and automated planning before application. For directory and taxonomy purposes, Atlantis is categorized under infrastructure automation, GitOps for IaC, and collaboration tooling for Terraform-based workflows.