The cloud and continuous delivery had a dramatic effect on infrastructure security. When following infrastructure as code, the entire infrastructure — which includes networks, firewalls and accounts — is defined in scripts and configuration files, and with Phoenix Servers and Environments, the infrastructure is recreated in each deployment, often many times a day. In such a scenario, testing the infrastructure after it's created is neither sufficient nor feasible. A tool that helps address this problem is cfn_nag. It scans the CloudFormation templates used with AWS for patterns that may indicate insecure infrastructure, and it does so before the infrastructure is created. Running a tool such as cfn_nag in a build pipeline is fast and it can detect a number of problems before they even reach a cloud environment.