This PR adds support for exposing Swift OpenAPI Lambda functions behind
an Application Load Balancer (ALB), providing an alternative to API
Gateway for HTTP routing to Lambda functions.
## Changes
### New ALB Support
- **OpenAPILambdaALB Protocol**: New protocol for ALB integration
alongside existing API Gateway support
- **ALB Event Handling**: Added `ALBTargetGroupRequest` and
`ALBTargetGroupResponse` support
- **HTTP Request Conversion**: Extension methods to convert ALB events
to/from HTTP requests/responses
### Core Library Updates
- **ALB-related source files**: New `/Sources/ALB/` directory with
ALB-specific implementations
- **Event Type Support**: Support for `ALBTargetGroupRequest` events
from Elastic Load Balancing
- **Response Mapping**: Proper mapping from OpenAPI responses to ALB
target group responses
### Complete ALB Example
- **QuoteAPI ALB Example**: Full working example in
`Examples/quoteapi-alb/`
- **Infrastructure as Code**: Complete SAM template with VPC, subnets,
security groups, and ALB
- **Build System**: Makefile and Docker build support for ALB deployment
- **Documentation**: Comprehensive README with ALB-specific deployment
instructions
### Key Files Added
```
Sources/ALB/
├── OpenAPILambdaALB.swift
└── ALBTargetGroup+HTTPRequest.swift
Examples/quoteapi-alb/
├── Package.swift
├── template.yaml
├── Makefile
├── README.md
├── Sources/QuoteAPI/QuoteService.swift
├── Sources/QuoteAPI/openapi.yaml
├── Sources/QuoteAPI/openapi-generator-config.yaml
└── events/GetQuote.json
```
## Usage
### Simple ALB Integration
```swift
@main
struct QuoteServiceALBImpl: APIProtocol, OpenAPILambdaALB {
func register(transport: OpenAPILambdaTransport) throws {
try self.registerHandlers(on: transport)
}
static func main() async throws {
let service = QuoteServiceALBImpl()
try await service.run()
}
// Your OpenAPI implementation...
}
```
### Key Differences from API Gateway
- Uses `OpenAPILambdaALB` instead of `OpenAPILambdaHttpApi`
- Handles `ALBTargetGroupRequest` events instead of
`APIGatewayV2Request`
- Returns `ALBTargetGroupResponse` instead of `APIGatewayV2Response`
- Requires VPC infrastructure (included in SAM template)
- No built-in authorization (implement via custom middleware if needed)
## Benefits
- **Cost Optimization**: ALB can be more cost-effective for high-traffic
applications
- **VPC Integration**: Native VPC support for private network access
- **Load Balancing**: Advanced load balancing features and health checks
- **WebSocket Support**: Future WebSocket support through ALB
- **Flexibility**: Choice between API Gateway and ALB based on use case
## Testing
- ✅ ALB example builds successfully with `sam build`
- ✅ Local testing with `sam local invoke`
- ✅ Complete infrastructure deployment via SAM
- ✅ HTTP requests properly routed through ALB to Lambda
- ✅ OpenAPI specification compatibility maintained
## Deployment
Deploy the ALB example:
```bash
cd Examples/quoteapi-alb
sam build && sam deploy --guided
```
Test the deployed endpoint:
```bash
curl http://[alb-dns-name]/stocks/AAPL
```
## Backward Compatibility
This is a purely additive change:
- Existing API Gateway implementations continue to work unchanged
- No breaking changes to existing APIs
- New ALB support is opt-in via protocol conformance
*Issue #, if available:*
*Description of changes:*
By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.
Updated the Swift workflow to run on Ubuntu instead of macOS and
simplified the trigger conditions.
*Issue #, if available:*
*Description of changes:*
By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.
---------
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
only PR are authorized
*Issue #, if available:*
*Description of changes:*
By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.
Apply recommendations in code and documentation
- [CI] restrict permissions to `read-all` instead of the default
`write-all`
- Example `openapi.yaml` : add a note about using `security:` definition
when deploying to production
- Example `README.md` : add a note about Lambda functions configuration
with improved security and scalability changes for production
environment
- Update this library to support the upcoming release of AWS Lambda
Runtime for Swift v2.
This change affects the public API (some `Sendable` added) and requires
a major version bump. I propose to release v2 to align this library's
major with the Swift AWS Lambda Runtime's major.
- Add a QuoteAPI example in the `Examples` directory
* Put query string into the path for OpenAPIGenerator code
* minor comments and formatting changes
---------
Co-authored-by: Sébastien Stormacq <sebastien.stormacq@gmail.com>
Sébastien Stormacq
Victor Hugo Barros
Franz Busch
Emlyn Murphy