Implementing Repository-Level Access Controls

Implementing Repository-Level Access Controls

Version control systems provide the first layer of access control for IaC. Modern platforms like GitHub, GitLab, and Bitbucket offer sophisticated permission models that enable fine-grained control over who can view, modify, and approve infrastructure code. These controls form the foundation of IaC security by preventing unauthorized code changes.

Branch protection rules enforce code review requirements and prevent direct modifications to critical branches. Production IaC code should require multiple approvals from authorized team members before merging. Automated security scans can serve as required status checks, ensuring code passes security validation before approval.

# Example GitHub branch protection configuration
# .github/settings.yml
repository:
  name: infrastructure-code
  description: IaC repository for cloud infrastructure
  private: true
  has_issues: true
  has_projects: false
  has_wiki: false
  default_branch: main

branches:
  - name: main
    protection:
      required_pull_request_reviews:
        required_approving_review_count: 2
        dismiss_stale_reviews: true
        require_code_owner_reviews: true
        dismissal_restrictions:
          users: []
          teams:
            - security-team
      required_status_checks:
        strict: true
        contexts:
          - security-scan/terraform
          - security-scan/checkov
          - policy-validation/opa
      enforce_admins: true
      required_linear_history: true
      restrictions:
        users: []
        teams:
          - infrastructure-team
          - security-team

  - name: develop
    protection:
      required_pull_request_reviews:
        required_approving_review_count: 1
      required_status_checks:
        contexts:
          - security-scan/terraform
          - unit-tests

# CODEOWNERS file for automatic review assignment
# infrastructure/production/ @infrastructure-team @security-team
# infrastructure/security-groups/ @security-team
# infrastructure/iam-roles/ @security-team @compliance-team
# infrastructure/development/ @dev-team @infrastructure-team

Code ownership patterns provide automated review assignment based on file paths or code patterns. Security-sensitive components like IAM roles, network configurations, and encryption settings can require security team approval. This automated assignment ensures appropriate expertise reviews all changes while reducing manual coordination overhead.