api: add namespace as part of endpoint external identifiers

[fristonio]

• Fixes Add namespace as part of external identifies of an endpoint #9331

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This change is 

[coveralls]

Coverage increased (+1.005%) to 45.509% when pulling 7735103 on fristonio/fix-9331 into 1810709 on master.

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[aanm]

test-me-please

[aanm]

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[gandro]

The PodName already contains the namespace (getK8sNamespaceAndPodName() returns the format namespace/podname). I don't quite understand the reason to add the namespace as a separate field.

[aanm]

We have been unnecessarily parsing the namespace from this field in places that use the podname. That's why the reason of adding a dedicated field. This field can be misleading as it specifies that is a pod name which it isn't, it's a namespace + pod name. Maybe this PR should also populate this field with the pod name only.

[gandro]

Note that the PodName field is currently parsed by Hubble, thus
removing the namespace from PodName would be a breaking API change (and therefore breaking Hubble), see:
https://github.com/cilium/hubble/blob/5d60255e1190b135959464bfac3954eaec215a51/pkg/parser/endpoint/endpoint.go#L36

It is probably something we can mitigate in Hubble (by checking for the availability of the Namespace field, and falling back to the old behavior if missing), but there might be other consumers that assume PodName contains the namespace.

[gandro]

To clarify, I'm fine with changing the contents of PodName to only contain the pod name. We will just have to do the corresponding PR in Hubble ASAP.

However as the PR is right now, I don't understand what problem it actually solves. Consumers that want the pod name still have to parse the namespace away, and I'm not aware of any consumers that are only interested in the namespace.

In any case, thanks for the PR @fristonio :)

[gandro]

As an alternative proposal, we could deprecate the above pod-name as is (i.e. it will stick to the current ns/pod format and mention in its description that it is deprecated), and introduce k8s-pod-name and k8s-pod-namespace fields that only contain the pod name or namespace respectively.

[aanm]

@gandro That makes sense because we have that concept already in our API

cilium/api/v1/models/endpoint_change_request.go

Lines 53 to 57 in 8a3ef84

	// Kubernetes namespace name
	K8sNamespace string `json:"k8s-namespace,omitempty"`
	// Kubernetes pod name
	K8sPodName string `json:"k8s-pod-name,omitempty"`

Maybe we should call it k8s-namespace to be similar to this field ^^^^

[fristonio]

Yeah, this sounds good. I will update the PR with the required changes.

[aanm]

test-me-please

[fristonio]

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[fristonio]

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[aanm]

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