Infrastructure as Code

Infrastructure as Code (IaC) is the practice of defining, provisioning, and managing infrastructure using machine-readable configuration files rather than manual setups. Tools like Terraform, Ansible, and Puppet enable teams to automate deployments, enforce consistency, and eliminate undocumented configuration drift.

Without IaC, infrastructure becomes prone to silent configuration changes, manual fixes, and inconsistencies between environments. Using IaC ensures:

• Reproducibility – Environments can be recreated identically.
• Transparency – All changes are logged and reviewed through version control.
• Safety – Automated checks reduce human error during large-scale changes.
• Collaboration – Multiple engineers can understand, review, and improve infrastructure.

• Declarative Configuration – Define the desired state, not the steps.
  • a list of imperative tasks should be idempotent, see below
• Idempotency – Applying the same configuration yields the same outcome every time.
• Version Control – Every change is reviewed, traceable, and reversible.
• Automation – Tasks such as provisioning, scaling, and patching run automatically.

• Reduced reliance on "tribal knowledge."
• Faster onboarding for new team members.
• Simple recovery from failures – rebuild instead of repair.
• Predictable, testable infrastructure rollouts.
• Enables DevOps practices like CI/CD and ephemeral environments.

• Terraform – Multi-cloud provisioning at scale.
• Ansible – Configuration management and automation. Imperative approach.
• Puppet – Policy-based infrastructure management. Declarative Approach.
• Kubernetes Manifests / Helm Charts – Declarative container orchestration.

• Drift Between Environments – Occurs when manual changes circumvent IaC.
• Poor Documentation – IaC is code, and code needs clear documentation.
• Lack of Testing – Misconfigurations can break entire systems.
• Overcomplication – Not everything must be automated at once.

• Commit all configuration to Git.
• Use code reviews for infrastructure changes.
• Test changes in staging environments before production.
• Avoid manual changes; enforce policy-as-code where possible.
• Regularly audit for drift.

• Ops Runbooks
• Hero Sysadmin
• Hero Developer