Gateway (and DataPlane) sorting and address priority

[shaneutt]

Problem Statement

For the purposes of clean kubectl get gateways output we're sorting addresses for Gateways based on whether or not they are LoadBalancer addresses (IPs or Hostnames). In practice most situations will only ever have a ClusterIP and a LoadBalancer IP, so this worked during the POC/pre-alpha stage to get the basics working but in the future when we have more than 2 addresses for Gateways this is not a consistent sort, AND we need to make a decision whether hostname or IP addresses should be prioritized.

Proposed Solution

• make the sorted of addresses for the Gateway status addresses consistent by introducing address type and address value sorting
• decide on whether hostname or ip addresses should have the highest priority, for the purposes of kubectl get gateways quick view output

Related Issues

Not necessarily a blocker but it might be good to take care of this one first:

• Kong/gateway-operator-archive#272

Acceptance Criteria

• when a Service has more than 2 addresses, address sorting is consistent so that I'm not getting extra reconciles
• the decision about which type of loadbalancer address has the highest precedence is documented

[randmonkey]

Are orders within same type (loadbalancer IPs, cluster IPs) defined here? LoadBalancer services could have multiple ingress addresses, and a service can have 2 cluster IPs if dualstack is supported.

[shaneutt]

Are orders within same type (loadbalancer IPs, cluster IPs) defined here? LoadBalancer services could have multiple ingress addresses, and a service can have 2 cluster IPs if dualstack is supported.

This was meant to encompass the situation where there are multiple LoadBalancer ips, yes. As for dual stack that one's a bit trickier since it gets so little use, but I think if you're up for it you could do that here as well.

[github-actions]

This issue has been automatically marked as stale due to 60 days of inactivity. Please update or comment if this is still relevant.

[pmalek]

This task basically means adding sorting to

kong-operator/controller/gateway/controller_reconciler_utils.go

Lines 203 to 235 in 39176b5

	func gatewayAddressesFromService(svc corev1.Service) ([]gwtypes.GatewayStatusAddress, error) {
	addresses := make([]gwtypes.GatewayStatusAddress, 0, len(svc.Status.LoadBalancer.Ingress))
	switch svc.Spec.Type {
	case corev1.ServiceTypeLoadBalancer:
	for _, serviceAddr := range svc.Status.LoadBalancer.Ingress {
	if serviceAddr.IP != "" {
	addresses = append(addresses, gwtypes.GatewayStatusAddress{
	Value: serviceAddr.IP,
	Type: lo.ToPtr(gatewayv1.IPAddressType),
	})
	}
	if serviceAddr.Hostname != "" {
	addresses = append(addresses, gwtypes.GatewayStatusAddress{
	Value: serviceAddr.Hostname,
	Type: lo.ToPtr(gatewayv1.HostnameAddressType),
	})
	}
	}
	default:
	// if the Service is not a LoadBalancer, it will never have any public addresses and its status address list
	// will always be empty, so we use its internal IP instead
	if svc.Spec.ClusterIP == "" {
	return addresses, fmt.Errorf("service %s doesn't have a ClusterIP yet, not ready", svc.Name)
	}
	addresses = append(addresses, gwtypes.GatewayStatusAddress{
	Value: svc.Spec.ClusterIP,
	Type: lo.ToPtr(gatewayv1.IPAddressType),
	})
	}
	return addresses, nil
	}

.