Infrastructure as Code (IaC)

Also Known As

TL;DR

Explanation

IaC applies software engineering practices — version control, code review, CI/CD, testing — to infrastructure management. Tools include Terraform (cloud-agnostic declarative provisioning), Ansible (agentless configuration management), CloudFormation (AWS-specific), and Pulumi (infrastructure in real programming languages). Benefits: reproducible environments (dev/staging/production parity), disaster recovery from code in minutes, peer review of infrastructure changes, and audit trail in git. For PHP deployments, Ansible playbooks commonly manage PHP-FPM configuration, nginx vhosts, TLS certificates, and Composer install workflows as part of the deployment pipeline.

Common Misconception

Why It Matters

Common Mistakes

• Making manual changes to infrastructure after IaC is in place — drift between code and reality causes the next apply to fail dangerously.
• Not using remote state — local Terraform state is lost when the machine dies and blocks collaboration.
• Storing secrets in IaC files — use a secrets manager and reference secrets by name, never value.
• Applying changes to production without testing in a staging environment first.

Code Examples

# Manual server setup — not reproducible:
ssh new-server
apt-get install nginx php8.3-fpm
nano /etc/nginx/sites-available/myapp  # Hand-edited
# No record of what was installed or configured
# Cannot reproduce exactly — 'works on this server'

# IaC with Terraform:
resource "aws_instance" "web" {
  ami           = "ami-12345"
  instance_type = "t3.medium"
  user_data     = file("setup.sh")  # Reproducible, version-controlled
}

# Terraform — declarative infrastructure
resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  tags = { Name = "php-app", Env = "production" }
}

resource "aws_db_instance" "main" {
  engine         = "mysql"
  engine_version = "8.0"
  instance_class = "db.t3.small"
  # ... version-controlled, code-reviewed, repeatable
}

# Apply
$ terraform plan   # dry run — shows changes
$ terraform apply  # provision/update

References

• ↗ https://www.terraform.io/intro
• ↗ https://docs.ansible.com/

Tags

Related Terms