# Decentralized firewall management
This sample shows how a decentralized firewall management can be organized using the [firewall factory](../../factories/net-vpc-firewall-yaml/README.md).
This approach is a good fit when Shared VPCs are used across multiple application/infrastructure teams. A central repository keeps environment/team
specific folders with firewall definitions in `yaml` format.
In the current example multiple teams can define their [VPC Firewall Rules](https://cloud.google.com/vpc/docs/firewalls)
for [dev](./firewall/dev) and [prod](./firewall/prod) environments using team specific subfolders. Rules defined in the
[common](./firewall/common) folder are applied to both dev and prod environments.
> **_NOTE:_** Common rules are meant to be used for situations where [hierarchical rules](https://cloud.google.com/vpc/docs/firewall-policies)
do not map precisely to requirements (e.g. SA, etc.)
This is the high level diagram:
![High-level diagram](diagram.png "High-level diagram")
The rules can be validated either using an automated process or a manual process (or a combination of
the two). There is an example of a YAML-based validator using [Yamale](https://github.com/23andMe/Yamale)
in the [`validator/`](validator/) subdirectory, which can be integrated as part of a CI/CD pipeline.
## Variables
| name | description | type | required | default |
|---|---|:---:|:---:|:---:|
| [billing_account_id](variables.tf#L15) | Billing account id used as default for new projects. | string
| ✓ | |
| [prefix](variables.tf#L29) | Prefix used for resources that need unique names. | string
| ✓ | |
| [root_node](variables.tf#L50) | Hierarchy node where projects will be created, 'organizations/org_id' or 'folders/folder_id'. | string
| ✓ | |
| [ip_ranges](variables.tf#L20) | Subnet IP CIDR ranges. | map(string)
| | {…}
|
| [project_services](variables.tf#L34) | Service APIs enabled by default in new projects. | list(string)
| | […]
|
| [region](variables.tf#L44) | Region used. | string
| | "europe-west1"
|
## Outputs
| name | description | sensitive |
|---|---|:---:|
| [fw_rules](outputs.tf#L15) | Firewall rules. | |
| [projects](outputs.tf#L33) | Project ids. | |
| [vpc](outputs.tf#L41) | Shared VPCs. | |