Description:
The HTTPRoute specification states that you can specify a backend service under backendRef and give the service name and port. It also permits creating custom resource definitions in addition to these two fields.
The implementations of the backend services can be secured using basic authentication, OAuth2, MTLS, etc. Along with these configs, backends can set their own timeout limits, retry configurations, etc. In order to cater these requirements I would like to a propose a custom resources definition as follows to hold the backend related information.

Backend CRD

apiVersion: gateway.envoy.io/v1alpha1
kind: Backend
metadata:
  name: order-svc
spec:
  certificateName: order-cert
  http2Enabled: false
  timeout: 2000
  credentials:
    type: Basic
    cred-secret: order-secret
  retryConfig:
    count: 3
    statusCode: 503
  circuitBreakers:
    maxConnections: 4
    maxRequests: 10
    maxPendingRequests: 5
    maxRetries: 4
    maxConnectionPools: 4

HTTPRoute with the Backend CRD

kind: HTTPRoute
apiVersion: gateway.networking.k8s.io/v1alpha2
metadata:
 name: bookinfo
spec:
 parentRefs:
   - name: eg-gw
 hostnames:
   - "bookinfo.com"
 rules:
 - matches:
   - path:
       type: PathPrefix
       value: /orders
     method: GET
   backendRefs:
   - group: gateway.envoy.io
     kind: Backend
     name: order-svc
     port: 8080

I did follow proposed changes in here as well - https://gist.github.com/danehans/30d45d80de58bf63d95fc3542d0ebec7

We would like to contribute to the project and would love to know your thoughts on this.