Remove namespace from core Entity

[jakubdyszkiewicz]

Summary

The idea is that our core model should not know anything about K8S namespace. To achieve that, we embed namespace into name. For example our name from core entity: sample.demo indicates that on k8s the name is sample and namespace is demo.

Postgres
In postgres we've got separate column for namespace. For now I left the column. We should solve the problem of migrations (especially since we plan to add new column which is creation/modify date).

Mesh
Mesh is now a Cluster scoped object on K8S. Meaning it does not belong to any namespace.

Changes from user perspective

kumactl output will look like following

❯❯❯ kumactl get dataplanes
MESH                  NAME                                     TAGS
kuma-system   demo-app-7df8d4b675-v6msc.kuma-demo      app=demo-app pod-template-hash=7df8d4b675 service=demo-app.kuma-demo.svc:8000
kuma-system   demo-client-6d8745c7d6-fvjfr.kuma-demo   app=demo-client pod-template-hash=6d8745c7d6 service=demo-client.kuma-demo.svc:3000

[CLAassistant]

All committers have signed the CLA.

[yskopets]

Let's also document migration path

[yskopets]

Let's bring this test back.

It's very interesting to see how ordering will work on k8s now.

I'm afraid that it doesn't make any sense from a user perspective. That is not ok and should be taken into account.

Maybe, it's more practical to choose namespace.name convention (or namespace:name like Marco once suggested)

[jakubdyszkiewicz]

Namespace now is in name and we've already got test for ordering the name. Ordering will work with name first and then namespace if it's present in the name.

Is this that important anyways? I think the only situation it will matter to user is when there are equal number of tags. We will soon change the ordering to take into account the modification date.

[yskopets]

Let's use strings.LastIndex() instead. I think, it will make the intention more clear

[jakubdyszkiewicz]

I don't think I understand how to apply the LastIndex() here. Can you provide what you have in mind?

[yskopets]

idx := strings.LastIndex(coreName, ".")
if idx == -1 {
  return "", "", errors.New(`name must include namespace after the dot, ex. "name.namespace"`)
}
if idx == len(coreName) - 1 {
  return "", "", errors.New("namespace must be non-empty")
}
return coreName[:idx], coreName[idx + 1:], nil

[yskopets]

Let's bring this test back.

It's very interesting to see how ordering will work on k8s now.

I'm afraid that it doesn't make any sense from a user perspective. That is not ok and should be taken into account.

Maybe, it's more practical to choose namespace.name convention (or namespace:name like Marco once suggested)

[yskopets]

idx := strings.LastIndex(coreName, ".")
if idx == -1 {
  return "", "", errors.New(`name must include namespace after the dot, ex. "name.namespace"`)
}
if idx == len(coreName) - 1 {
  return "", "", errors.New("namespace must be non-empty")
}
return coreName[:idx], coreName[idx + 1:], nil