Why infrastructure as code

Infrastructure as code (IaC) means defining infrastructure, such as networks, virtual machines, storage and permissions, in text files instead of clicking through a console or running ad hoc commands.

Benefits

• Repeatable: the same files create the same environment in development, test and production.
• Reviewable: changes go through pull requests, so others can check them.
• Versioned: the history shows what changed, when and why, and you can roll back.
• Documented: the code describes the system, so the knowledge is not held by one person alone.
• Auditable: it is easier to show what exists and who approved it.

Common pitfalls

• Manual console changes that the code does not know about, which cause drift
• Secrets committed to the repository
• Large, unreviewed changes that are hard to undo

Where to start

Pick one small, low-risk environment, such as a test network with a single virtual machine, and manage all of it through code. Expand once the team trusts the workflow.