Multiple istio-ingress-k8s charms try to apply changes in a single underlying HTTPRoute resource which causes conflicts

[wood-push-melon]

Bug Description

This happens if a requirer charm application would like to use multiple istio-ingress-k8s charms to expose services.

If a requirer charm integrates with multiple istio-ingress-k8s charms, the istio-ingress-k8s charms will apply changes to a single HTTPRoute. This will lead to conflict errors in the istio-ingress-k8s charms.

From what I understand, it is supposed to create multiple HTTPRoutes referenced by different gateways.

Please see more details below.

cc @shipperizer

To Reproduce

# Deploy public ingress
juju deploy istio-ingress-k8s istio-ingress-public --channel edge

# Deploy admin ingress
juju deploy istio-ingress-k8s istio-ingress-admin --channel edge

# Deploy client charm
juju deploy hydra --channel edge

# Deploy dependency charms
juju deploy postgresql-k8s --channel 14/stable --trust
juju integrate hydra postgresql-k8s

# Integrate client charm with public ingress
juju integrate hydra:public-ingress istio-ingress-public

# Integrate client charm with admin ingress. This will cause errors
juju integrate hydra:admin-ingress istio-ingress-admin

Environment

microk8s: v1.27.16
istio-ingress-k8s channel: edge

Relevant log output

unit-istio-ingress-admin-0: 19:31:05 INFO unit.istio-ingress-admin/0.juju-log ingress:24: Applying resources
unit-istio-ingress-admin-0: 19:31:05 INFO unit.istio-ingress-admin/0.juju-log ingress:24: HTTP Request: PATCH https://10.152.183.1/apis/gateway.networking.k8s.io/v1/namespaces/test/httproutes/hydra-http?fieldManager=istio-ingress-admin "HTTP/1.1 409 Conflict"
unit-istio-ingress-admin-0: 19:31:05 ERROR unit.istio-ingress-admin/0.juju-log ingress:24: Uncaught exception while in charm code:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/generic_client.py", line 232, in raise_for_status
    resp.raise_for_status()
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/httpx/_models.py", line 763, in raise_for_status
    raise HTTPStatusError(message, request=request, response=self)
httpx.HTTPStatusError: Client error '409 Conflict' for url 'https://10.152.183.1/apis/gateway.networking.k8s.io/v1/namespaces/test/httproutes/hydra-http?fieldManager=istio-ingress-admin'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/409

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/./src/charm.py", line 684, in <module>
    main(IstioIngressCharm)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/main.py", line 45, in main
    return _main.main(charm_class=charm_class, use_juju_for_storage=use_juju_for_storage)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/_main.py", line 543, in main
    manager.run()
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/_main.py", line 529, in run
    self._emit()
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/_main.py", line 518, in _emit
    _emit_charm_event(self.charm, self.dispatcher.event_name, self._juju_context)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/_main.py", line 134, in _emit_charm_event
    event_to_emit.emit(*args, **kwargs)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 347, in emit
    framework._emit(event)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 857, in _emit
    self._reemit(event_path)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 947, in _reemit
    custom_handler(event)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/lib/charms/traefik_k8s/v2/ingress.py", line 461, in _handle_relation
    self.on.data_provided.emit(  # type: ignore
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 347, in emit
    framework._emit(event)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 857, in _emit
    self._reemit(event_path)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/ops/framework.py", line 947, in _reemit
    custom_handler(event)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/./src/charm.py", line 234, in _on_ingress_data_provided
    self._sync_all_resources()
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/./src/charm.py", line 478, in _sync_all_resources
    self._sync_ingress_resources()
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/./src/charm.py", line 580, in _sync_ingress_resources
    krm.reconcile(current_ingresses)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube_extensions/batch/_kubernetes_resource_manager.py", line 179, in reconcile
    self.apply(resources=resources, force=force)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube_extensions/batch/_kubernetes_resource_manager.py", line 102, in apply
    apply_many(
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube_extensions/batch/_many.py", line 70, in apply_many
    returns[i] = client.apply(
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/client.py", line 754, in apply
    return self.patch(
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/client.py", line 489, in patch
    return self._client.request(
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/generic_client.py", line 308, in request
    return self.handle_response(method, resp, br)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/generic_client.py", line 248, in handle_response
    self.raise_for_status(resp)
  File "/var/lib/juju/agents/unit-istio-ingress-admin-0/charm/venv/lightkube/core/generic_client.py", line 234, in raise_for_status
    raise transform_exception(e)
lightkube.core.exceptions.ApiError: Apply failed with 3 conflicts: conflicts with "istio-ingress-public":
- .metadata.labels.app.kubernetes.io/instance
- .spec.parentRefs
- .spec.rules