Add support for HTTP/2 listener protocol in OCI Load Balancer

[raniellyferreira]

Problem

When using Layer 7 load balancers with service.beta.kubernetes.io/oci-load-balancer-backend-protocol: "HTTP", the HTTPS listener on port 443 was defaulting to HTTP/1.1 instead of respecting the oci.oraclecloud.com/oci-load-balancer-protocol: "HTTP2" annotation.

This prevented users from configuring HTTP/2 on the listener while maintaining HTTP communication with backends, which is a common configuration pattern for performance optimization.

Solution

Added support for the oci.oraclecloud.com/oci-load-balancer-protocol annotation to allow independent configuration of listener and backend protocols.

Key Changes

1. New annotation: Added ServiceAnnotationLoadBalancerProtocol = "oci.oraclecloud.com/oci-load-balancer-protocol"
2. Separate protocol handling: Modified getListenersOciLoadBalancer() to handle listener and backend protocols independently
3. HTTP/2 support: Added HTTP2 to the list of supported listener protocols
4. Enhanced validation: Added proper error handling for invalid protocol values
5. Backward compatibility: All existing functionality is preserved

Usage Example

apiVersion: v1
kind: Service
metadata:
  name: nginx-ingress-controller
  annotations:
    # Backend communicates via HTTP
    service.beta.kubernetes.io/oci-load-balancer-backend-protocol: "HTTP"
    # Listener uses HTTP/2 for better performance
    oci.oraclecloud.com/oci-load-balancer-protocol: "HTTP2"
spec:
  type: LoadBalancer
  ports:
    - name: https
      port: 443
      targetPort: https

Supported Protocols

Backend Protocol (service.beta.kubernetes.io/oci-load-balancer-backend-protocol):

• TCP (default)
• HTTP
• GRPC

Listener Protocol (oci.oraclecloud.com/oci-load-balancer-protocol):

• TCP (default, matches backend protocol)
• HTTP
• HTTP2 NEW
• GRPC

Testing

• Added comprehensive test coverage for HTTP2 and HTTP listener protocols
• All existing tests continue to pass
• Build verification successful
• Backward compatibility maintained

Before/After

Before: HTTP-443 listener defaulted to HTTP/1.1 regardless of the protocol annotation
After: HTTP-443 listener correctly uses HTTP/2 when oci.oraclecloud.com/oci-load-balancer-protocol: "HTTP2" is specified

This change resolves issue #449 and enables users to optimize their load balancer configurations for modern HTTP/2 performance while maintaining flexibility in backend communication protocols.

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[Copilot]

Pull Request Overview

Adds independent listener protocol configuration to OCI Load Balancer resources, introducing HTTP/2 support via a new annotation and updating listener naming and timeout logic.

• New oci.oraclecloud.com/oci-load-balancer-protocol annotation for listener protocol
• getListenersOciLoadBalancer split into backendProtocol and listenerProtocol, with HTTP2 validation
• Listener naming and default idle timeouts updated to include HTTP/2

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
pkg/cloudprovider/providers/oci/load_balancer_util.go	Normalize listener names to use the "HTTP" prefix for HTTP/2
pkg/cloudprovider/providers/oci/load_balancer_spec.go	Added listenerProtocol override, HTTP2 support, and idle timeout map
pkg/cloudprovider/providers/oci/load_balancer_spec_test.go	Added test cases covering HTTP2 and HTTP listener protocols

Comments suppressed due to low confidence (1)

pkg/cloudprovider/providers/oci/load_balancer_spec.go:1163

• The comment is outdated now that HTTP/2 (and gRPC) are supported; please update it to reflect all currently supported protocols.

			// At that point LB only supports HTTP and TCP

[raniellyferreira]

Up