feat: add LB session persistence and listener idle timeout features

[mnogueiraops]

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Subject: feat: Add LB Cookie Session Persistence and Listener Idle Timeout

Related Issue: Fixes #106 + Add LB side Cookie Session Persistence

Description:

This pull request introduces two significant enhancements to the OCI Native Ingress Controller, allowing finer-grained control over OCI Load Balancer configurations through IngressClassParameters:

1. Load Balancer (LB) Cookie-Based Session Persistence:
   • A new lbCookieSessionPersistenceConfiguration field can now be defined within IngressClassParameters. This allows users to enable and configure LB cookie stickiness (e.g., cookie name, max-age/timeout, path, domain, security attributes) for backend sets.
   • The ingress controller now applies this configuration to backend sets created based on Ingress rules.
   • The ingressclass controller also applies this configuration to the default backend set of the Load Balancer.
2. Default Listener Idle Timeout:
   • A new defaultListenerIdleTimeoutInSeconds field can be specified in IngressClassParameters.
   • The ingress controller uses this value to configure the idle timeout on listeners (e.g., HTTP, HTTPS) it provisions for Ingress resources.

Summary of Changes:

• API Updated (api/v1beta1/ingressclassparameters_types.go):
  • Added lbCookieSessionPersistenceConfiguration (and its LbCookieSessionPersistenceConfigurationDetails struct) to IngressClassParametersSpec.
  • Added defaultListenerIdleTimeoutInSeconds to IngressClassParametersSpec.
• Controller Logic Modified:
  • pkg/controllers/ingressclass/ingressclass.go: Updated to handle lbCookieSessionPersistenceConfiguration for the default backend set.
  • pkg/controllers/ingress/ingress.go:
    • Enhanced to apply defaultListenerIdleTimeoutInSeconds during listener creation and updates.
    • Refactored syncBackendSet to apply lbCookieSessionPersistenceConfiguration to Ingress-derived backend sets during creation and updates, ensuring a consolidated update approach.
• OCI Client & LoadBalancer Helpers Updated:
  • Modified methods in pkg/loadbalancer/loadbalancer.go (CreateListener, UpdateListener, CreateBackendSet, UpdateBackendSet) to support the new parameters.
  • Extended LoadBalancerInterface in pkg/oci/client/loadbalancer.go (e.g., added GetBackendSet) and its implementation.
• Build Error Corrections: Addressed various compilation issues identified during development, including CRD generation marker fixes, OCI SDK type mismatches, and incorrect function signatures/calls.
• Examples Updated: The example IngressClassParameters YAML (deploy/example/customresource/ingressclassparameter.yaml) has been updated with commented-out sections for the new configurations.

Documentation Impact:

• The primary README.md or other documentation detailing IngressClassParameters fields will need to be updated to describe lbCookieSessionPersistenceConfiguration and defaultListenerIdleTimeoutInSeconds.

Validation Steps:

Prerequisites:

1. Ensure the controller is built with these changes.
2. Regenerate the IngressClassParameters CRD manifest (e.g., using controller-gen crd paths=./api/v1beta1/... output:crd:dir=./deploy/manifests/oci-native-ingress-controller/crds) and apply the updated CRD to your Kubernetes cluster (kubectl apply -f ...). (Already commited with this done)
3. Deploy the new controller image.

1. Validate LB Cookie Session Persistence:
a. Define an IngressClassParameters resource with the lbCookieSessionPersistenceConfiguration section (e.g., set cookieName, timeoutInSeconds).
b. Create an IngressClass referencing these parameters.
c. Deploy an application with an Ingress using this IngressClass.
d. Verify in OCI Console: Check the OCI Load Balancer. The backend set corresponding to your Ingress rule should have the specified cookie session persistence settings.
e. Test Stickiness: Make multiple requests from a single client to your application's endpoint. Verify requests are routed to the same backend pod and check for the presence of the configured cookie in HTTP responses.

2. Validate Default Listener Idle Timeout:
a. Define an IngressClassParameters resource setting defaultListenerIdleTimeoutInSeconds (e.g., to 120).
b. Ensure your IngressClass uses these parameters.
c. Deploy an Ingress that creates listeners.
d. Verify in OCI Console: Check the listeners on the OCI Load Balancer. Their "Idle Timeout" should match the value from defaultListenerIdleTimeoutInSeconds.

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