默认情况下为命名空间设置 priorityclass

Question

I would like to know how it's possible to set a priorityClass by default for all pods in a specific namespace without using a globalvalue: true

may be with admission controller but i don't know.

Do you have an concret example for that?

Answer 1

PriorityClass : A PriorityClass is a non-namespaced object

PriorityClass also has two optional fields: globalDefault and description.

The globalDefault field indicates that the value of this PriorityClass should be used for Pods without a priorityClassName.

Only one PriorityClass with globalDefault set to true can exist in the system . If there is no PriorityClass with globalDefault set, the priority of Pods with no priorityClassName is zero.

Create Priority Class as using below yaml (no globalDefault flag is set)

apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
  name: high-priority
value: 1000000
description: "This priority class should be used for pods."


$ kubectl get priorityclasses.scheduling.k8s.io
NAME                      VALUE        GLOBAL-DEFAULT   AGE
high-priority             1000000      false            10s

Now add priority class to pod manifest and schedule them in your namespace

$ kubectl create namespace priority-test
namespace/priority-test created

$ kubectl get namespaces 
NAME              STATUS   AGE
default           Active   43m
kube-node-lease   Active   43m
kube-public       Active   43m
kube-system       Active   43m
priority-test     Active   5s

Example: pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - name: nginx
    image: nginx
  priorityClassName: high-priority



$ kubectl apply -f pod.yaml -n priority-test
pod/nginx created


ubuntu@k8s-master-1:~$ kubectl get all -n priority-test
NAME        READY   STATUS    RESTARTS   AGE
pod/nginx   1/1     Running   0          25s


$ kubectl describe pod -n priority-test nginx  | grep -i priority
Namespace:            priority-test
Priority:             1000000
Priority Class Name:  high-priority
  Normal  Scheduled  <unknown>  default-scheduler      Successfully assigned priority-test/nginx to worker-1

Answer 2

Currently per namespace priorities are not possible.

But you can achieve similar result if instead you set default priorityClass with globalDefault: true and eg value: 1000 . Next create another lower priority class and with eg value: 100 and add it to all dev/staging pods.

Btw. not directly related to the question but it would be much easier to accomplish what you need if you use nodeSelector s and schedule dev pods to separate nodes. This way production pods don't have to compete for resources with non-essential pods.