This commit deletes the k8s informer based Cilium Ingress controller.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

Currently, the slim version of the k8s golang model gets used for the
Cilium Ingress controller. The main goal of the slim model is to keep
the memory footprint at a minimal level. This is especially important
for big resources that occur often in a cluster.

There's no actual reason to use the slim model in Cilium Ingress reconciler.

Therefore, all the Ingress related helper functions are migrated from the
slim to the "normal" model.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit restores the functions `regenerate` & `isEffectiveLoadBalancerModeDedicated`
from the old Cilium Ingress controller.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit lays out the basic reconcile skeleton that should be implemented
with the new Cilium Ingress reconciler.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit implements the creation and update of dependent k8s resources
during a reconciliation.

Shared loadbalancing mode:
* Creation & update of the shared CiliumEnvoyConfig in the Cilium installation namespace

The shared CiliumEnvoyConfig contains the aggregated config of all shared Ingress resources
in the cluster.

Dedicated loadbalancing mode:
* Dedicated loadbalancer Service in the same namespace as the Ingress
* Dedicated Endpoints in the same namespace as the Ingress
* Deidcated CiliumEnvoyConfig in the same namespace as the Ingress

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit implements the cleanup of dependent resources that were
created during previous reconciliation runs.

Resources need to be cleaned-up in various scenarios:

* Shared Ingress gets deleted
* Loadbalancer Mode of Ingress gets changed (dedicated <-> shared)
* Change of responsible ingress controller (IngressClass)

In these cases the reconciler checks whether some resources need to be
cleaned up or udpated (shared CEC).

Note: resources (Service, Endpoints & CiliumEnvoyConfig) of dedicated
Ingresses are deleted via K8s Garbage Collection (via OwnerReferences).

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit implements the update of the Ingress' loadbalancer
status during reconciliation.

It checks whether the related loadbalancer Service already has
an IP assigned. If it's present, it writes the status of the Ingress
accordingly.

In case of a change in the Ingress controller ownership, the reconciler
tries to reset the loadbalancer status of the reconciler.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit fixes the usage of ownerreferences.

Shared loadbalancing mode:

K8s OwnerReferences are only meant to reference resources in the same namespace.
Therefore, the shared CiliumEnvoyConfig in the namespace of Cilium should not
contain any OwnerReferences, as it would make use of non-supported cross-namespace
references. In these cases the reconciler is responsible to cleanup/update the shared
CiliumEnvoyConfig - and can not rely on K8s GC functionality.

Dedicated loadbalancing mode:

The related resources Service, Endpoints & CiliumEnvoyConfig should contain only one
OwnerReference to the Ingress resource. This reference should be marked as controlled
by the Cilium Ingress controller.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit replaces the package logger with an injected logger
by the Hive framework.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit renames and moves the Ingress related constants to
the corresponding annotation package.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

Whenever there's a change on the default ingress-controller annotation
on the cilium IngressClass (`ingressclass.kubernetes.io/is-default-class`),
the relevant Ingresses need to be reconciled. There might be the possibility
that Cilium is no longer the Ingress controller for the Ingresses that don't
have an explicit controller set via (legacy) annotation or `ingressClassName`.

Therefore, this commit registers a corresponding watch on the cilium IngressClass.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit optimizes the watch on the Ingress resources to only watch for Ingresses
that are managed by Cilium.

This includes the Ingresses that were managed by Cilium before the change (e.g. change
of the field `ingressClassName`). This is necessary to cleanup potentially
existing resources from previous reconciliations.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit refactores the existing regeneration logic by introducing
explicit functions to build the model for the shared and dedicated
loadbalancing case.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

This commit adds unit tests for the Ingress helper & reconciler.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>