# waf — WAFv2 Web ACL

> **Module kind:** primitive  |  **Version:** 1.0.0

A WAFv2 Web ACL scoped to CloudFront. It applies managed rule groups by
default and can be associated with a CloudFront distribution to filter
traffic before it reaches the origin. CloudFront-scoped Web ACLs are
always created in `us-east-1`.

## Resources

| Resource | Type | Purpose |
|----------|------|---------|
| `webacl` | `aws_wafv2_web_acl` | WAFv2 Web ACL with managed rules |

## Inputs

| Name | Type | Required | Default | Description |
|------|------|----------|---------|-------------|
| `name` | string | yes | — | Name of the Web ACL |
| `scope` | string | no | `cloudfront` | Scope of the Web ACL (default cloudfront for CloudFront associations) |
| `default_action` | string | no | `allow` | Default action (default allow) |
| `rules` | string | no | — | Optional custom rules as JSON (default: managed rules only) |
| `region` | string | yes | — | AWS region (CloudFront-scoped WAF is always us-east-1; the adapter ignores this for cloudfront scope) |

## Outputs

| Name | Type | Description |
|------|------|-------------|
| `web_acl_arn` | arn | The WAF Web ACL ARN |

## Usage

```json
{
  "id": "waf",
  "type": "aws:wafv2:webacl",
  "module": "waf@1.0.0",
  "inputs": {
    "name": "acdl-static-assets-waf",
    "scope": "cloudfront",
    "default_action": "allow",
    "region": "us-east-1"
  }
}
```

The `web_acl_arn` output is typically wired as a `ref:` expression into
the `cloudfront` primitive's `waf_web_acl_arn` input inside a module
composition (see `modules/l2/static-assets`).

## Compliance extension points

- **Rate limiting** — add a rate-based rule to cap requests per IP
  (SOC2 CC6.1, DORA operational resilience).
- **Geo blocking** — add a geo-match statement to block/allow countries
  for data-residency compliance (GDPR Art.44, SOC2 CC6.1).
- **Custom rules** — add custom rule statements for application-specific
  filtering (e.g. block SQLi/IP allow-lists) (SOC2 CC6.1).
- **Logging** — enable WAF access logging to S3/CloudWatch/Kinesis for
  auditability (SOC2 CC7.2, DORA audit trail).

## Examples

Validated example contracts are in [`examples/`](examples/). The platform-test
pipeline validates them against `schemas/contract.schema.json`.

### Simple

A minimal deployment:

[`examples/simple.yml`](examples/simple.yml)
```yaml
environment: dev
id: waf
infrastructure:
  waf:
    inputs:
      name: my-waf
      region: us-east-1
    version: 1.0.0
name: waf-firewall
```

### Complex

A production deployment with optional inputs:

[`examples/complex.yml`](examples/complex.yml)
```yaml
environment: dev
id: waf
infrastructure:
  waf:
    inputs:
      default_action: allow
      name: my-production-waf
      region: us-east-1
      scope: cloudfront
    version: 1.0.0
name: waf-firewall
```

## Versioning

`1.0.0` — interface MAJOR, behavior MINOR, lifecycle PATCH. MAJOR bumps
require a new registry entry (immutable publication); old entries enter
a 12-month deprecation window.