How to use Atlantis for Terraform in a team?

Question

Accepted Answer

**Atlantis** — server for automatic planning and applying Terraform via Pull Requests.

**How it works:**
1. Developer creates a PR with Terraform changes.
2. Atlantis automatically runs `terraform plan`.
3. Plan results are commented in the PR.
4. For apply, the comment `atlantis apply`.

**Installation (Docker):**
```bash
docker run -d \
  -p 4141:4141 \
  -e ATLANTIS_GITHUB_USER=myuser \
  -e ATLANTIS_GITHUB_TOKEN=xxx \
  -e ATLANTIS_WEBHOOK_SECRET=xxx \
  ghcr.io/runatlantis/atlantis:latest server
```

**atlantis.yaml (in repository root):**
```yaml
version: 3
projects:
  - name: production-vpc
    dir: infrastructure/production/vpc
    workspace: default
    autoplan:
      when_modified: ["*.tf", "*.tfvars"]
      enabled: true
    apply_requirements: [approved, mergeable]
    workflow: custom
  - name: production-eks
    dir: infrastructure/production/eks
    workspace: default
    apply_requirements: [approved]

workflows:
  custom:
    plan:
      steps:
        - init
        - run: terraform validate
        - plan:
            extra_args: ["-var-file", "terraform.tfvars"]
    apply:
      steps:
        - apply:
            extra_args: ["-var-file", "terraform.tfvars"]
```

**Pre/Post workflow hooks:**
```yaml
hooks:
  pre_plan:
    - run: tflint --config .tflint.hcl
  post_apply:
    - run: python notify_slack.py
```

**Advantages:** Code review for infrastructure, audit, automatic plan, locking.

DevOps: How to use Atlantis for Terraform in a team?