AWS services in this solution

AWS service	Description
AWS CodeBuild	Core. CodeBuild validates the configuration files (firewall, firewall policy, and rule group) and checks if the JSON format is valid.
AWS CodePipeline	Core. CodePipeline validates, tests, and implements changes based on updates to the configuration package in the S3 bucket.
AWS Network Firewall	Core. This solution automates the process of provisioning a centralized Network Firewall to inspect traffic between VPCs.
Amazon VPC	Core. This solution creates an inspection VPC with four subnets to support Transit Gateway attachments and Network Firewall endpoints.
Amazon S3	Supporting. This solution creates S3 buckets for firewall configurations, source code, artifacts, and logs.
AWS Systems Manager	Supporting. Provides application-level resource monitoring and visualization of resource operations and cost data.
AWS Transit Gateway	Optional. This solution creates Transit Gateway attachments for your VPCs if you provide an existing transit gateway ID.