Merge pull request #7079 from ourcolorfuldays/fix3

Make more precisely
This commit is contained in:
Joseph Heck
2018-02-12 15:36:47 -08:00
committed by GitHub
@@ -185,7 +185,7 @@ value V that is running a pod that has a label with key "security" and value "S1
rule says that the pod prefers to not schedule onto a node if that node is already running a pod with label
having key "security" and value "S2". (If the `topologyKey` were `failure-domain.beta.kubernetes.io/zone` then
it would mean that the pod cannot schedule onto a node if that node is in the same zone as a pod with
label having key "security" and value "S2".) See the [design doc](https://git.k8s.io/community/contributors/design-proposals/scheduling/podaffinity.md).
label having key "security" and value "S2".) See the [design doc](https://git.k8s.io/community/contributors/design-proposals/scheduling/podaffinity.md)
for many more examples of pod affinity and anti-affinity, both the `requiredDuringSchedulingIgnoredDuringExecution`
flavor and the `preferredDuringSchedulingIgnoredDuringExecution` flavor.
@@ -194,10 +194,10 @@ The legal operators for pod affinity and anti-affinity are `In`, `NotIn`, `Exist
In principle, the `topologyKey` can be any legal label-key. However,
for performance and security reasons, there are some constraints on topologyKey:
1. For affinity and for `RequiredDuringScheduling` pod anti-affinity,
1. For affinity and for `requiredDuringSchedulingIgnoredDuringExecution` 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`).
2. For `requiredDuringSchedulingIgnoredDuringExecution` 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 `preferredDuringSchedulingIgnoredDuringExecution` 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`