Getting started with infrastructure as code

What infrastructure as code gives you

Infrastructure as code (IaC) means describing servers, networks, and cloud resources in version-controlled files and applying them with tooling rather than clicking through consoles. The benefits are practical: changes are reviewable, environments can be recreated, and there is a record of who changed what and why.

Two tool categories are commonly used together. Provisioning tools such as Terraform and OpenTofu create and change resources like networks, virtual machines, and managed services. Configuration management tools such as Ansible bring servers to a desired state by installing packages, writing configuration, and managing services.

Do not try to codify everything at once

The most common reason IaC adoption stalls is scope. Start with one slice that is repeated, risky, or hard to audit: a network and its security rules, a set of DNS records, or the setup for a new environment. Get that slice fully under code, reviewed, and applied through a consistent process before moving on.

Bring existing resources under management

Most teams already have infrastructure that was created by hand. Terraform and OpenTofu can import existing resources into state so that they can be managed as code from then on. Import carefully, run a plan afterwards, and aim for a plan that shows no changes before you start modifying anything.

Treat state as sensitive and shared

Provisioning tools keep a state file that maps your code to real resources. Store it in a remote backend with locking so two people cannot apply at once, restrict access to it, and never commit it to Git. State can contain sensitive values, so it should be protected like a credential store.

Make the plan the unit of review

The most valuable habit in IaC is reading the plan. Run formatting, validation, and a plan on every pull request, review the proposed changes, and apply the same reviewed plan from the pipeline.

terraform init
terraform fmt -check
terraform validate
terraform plan -out=tfplan
terraform apply tfplan

Introduce modules when patterns repeat

Resist the urge to build a module library on day one. Write the resources directly until you have seen the same pattern two or three times, then extract a module with a small, clear interface. Abstractions created too early tend to encode guesses that later need to be undone.

Keep secrets out of code

Never hard-code passwords, tokens, or keys in configuration files. Reference a secrets manager or inject values at apply time, and make sure secret scanning is part of the repository checks.

Detect and reduce drift

Drift happens when someone changes a resource outside of code. Run plans on a schedule to surface it, decide whether the code or the environment is correct, and over time restrict console write access so that the code path is the easiest path.