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fixed #3968 (#4105) 

* fixed #3968

* advise from @chenopis
reviewable/pr4113/r2^2
Vincent 2017-06-24 05:03:07 +08:00 committed by Andrew Chen
parent 79eca9b815
commit 80c90ba8fb
1 changed files with 7 additions and 6 deletions
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13
docs/concepts/configuration/assign-pod-node.md
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@ -190,13 +190,14 @@ flavor and the `preferredDuringSchedulingIgnoredDuringExecution` flavor.
As with node affinity, the legal operators for pod affinity and anti-affinity are `In`, `NotIn`, `Exists`, `DoesNotExist`, `Gt`, `Lt`.
In principle, the `topologyKey` can be any legal label value. However,
for performance reasons, only a limited set of topology keys are allowed.
By default the allowed topology keys are:
In principle, the `topologyKey` can be any legal label-key. However,
for performance and security reasons, there are some constraints on topologyKey:
* `kubernetes.io/hostname`
* `failure-domain.beta.kubernetes.io/zone`
* `failure-domain.beta.kubernetes.io/region`
1. For affinity and for `RequiredDuringScheduling` pod anti-affinity,
empty `topologyKey` is not allowed.
2. For `RequiredDuringScheduling` pod anti-affinity, the admission controller `LimitPodHardAntiAffinityTopology` was introduced to limit `topologyKey` to `kubernetes.io/hostname`. If you want to make it available for custom topologies, you may modify the admission controller, or simply disable it.
3. For `PreferredDuringScheduling` pod anti-affinity, empty `topologyKey` is interpreted as "all topologies" ("all topologies" here is now limited to the combination of `kubernetes.io/hostname`, `failure-domain.beta.kubernetes.io/zone` and `failure-domain.beta.kubernetes.io/region`).
4. Except for the above cases, the `topologyKey` can be any legal label-key.
In addition to `labelSelector` and `topologyKey`, you can optionally specify a list `namespaces`
of namespaces which the `labelSelector` should match against (this goes at the same level of the definition as `labelSelector` and `topologyKey`).