一、默认的requests和limits

说明：配置的默认requests和limits作用层面仅限于pod，对deployment等高级调度资源不生效

1.定义一个yaml文件

[root@k8s-master01 study]# vim limitrange.yaml 
apiVersion: v1
kind: LimitRange
metadata:
  name: cpu-mem-limit-range
spec:
  limits:
  - default:
      cpu: 1
      memory: 512Mi
    defaultRequest:
      cpu: 0.5
      memory: 256Mi
    type: Container
#default：默认limits配置
#defaultRequest：默认requests配置

2.开始创建

[root@k8s-master01 study]# kubectl create ns rq-test

[root@k8s-master01 study]# kubectl create -f limitrange.yaml -n rq-test

3.创建deployment

[root@k8s-master01 study]# kubectl create deploy test-1 --image=registry.cn-hangzhou.aliyuncs.com/zq-demo/nginx:1.14.2 --replicas=3 -n rq-test

4.查看deployment创建情况

[root@k8s-master01 study]# kubectl get deployment -n rq-test

NAME     READY   UP-TO-DATE   AVAILABLE   AGE

test-1   3/3     3            3           8m11s

5.在线编辑查看resources是否已配置，观察到没有配置

[root@k8s-master01 study]# kubectl edit deployment test-1 -n rq-test

...

... 

       name: nginx

        resources: {}

...

... 

6.查看pod生成的默认参数。观察到已成功添加到默认参数，同时说明limitrange对deployment不生效，而对pod生效

[root@k8s-master01 study]# kubectl get po -n rq-test
NAME                       READY   STATUS        RESTARTS   AGE
test-1-74795ddfbc-6zxft    1/1     Running       0          13m
test-1-74795ddfbc-hhsnd    1/1     Running       0          13m
test-1-74795ddfbc-lxpjh    1/1     Running       0          6s
[root@k8s-master01 study]# kubectl get po test-1-74795ddfbc-lxpjh   -n rq-test -oyaml
...
...
    imagePullPolicy: IfNotPresent
    name: nginx
    resources:
      limits:
        cpu: "1"
        memory: 512Mi
      requests:
        cpu: 500m
        memory: 256Mi
...
...

二、限制容器可以使用的最大和最小资源

1.在上面基础修改yaml文件

[root@k8s-master01 study]# vim limitrange.yaml 
apiVersion: v1
kind: LimitRange
metadata:
  name: cpu-mem-limit-range
spec:
  limits:
  - default:
      cpu: 1
      memory: 512Mi
    defaultRequest:
      cpu: 0.5
      memory: 256Mi
    max:
      cpu: "2"
      memory: 1Gi
    min:
      cpu: "10m"
      memory: 128Mi
    type: Container
max：内存CPU的最大配置
min：内存CPU的最小配置

2.重新部署

[root@k8s-master01 study]# kubectl create ns rq-test

[root@k8s-master01 study]# kubectl replace -f limitrange.yaml -n rq-test 

3.结果验证，观察到参数已经配置完成

[root@k8s-master01 study]# kubectl get limitrange -n rq-test -oyaml
apiVersion: v1
items:
- apiVersion: v1
  kind: LimitRange
  metadata:
    creationTimestamp: "2022-12-11T02:11:12Z"
    name: cpu-mem-limit-range
    namespace: rq-test
    resourceVersion: "31880"
    uid: 3a3f1870-890c-4b67-aaf4-343b49bc6d75
  spec:
    limits:
    - default:
        cpu: "1"
        memory: 512Mi
      defaultRequest:
        cpu: 500m
        memory: 256Mi
      max:
        cpu: "2"
        memory: 1Gi
      min:
        cpu: 10m
        memory: 128Mi
      type: Container
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

4.在线编辑deployment,修改内存以及CPU参数小于最小值

[root@k8s-master01 study]# kubectl edit deploy test-1 -n rq-test
...
...
        resources: 
          requests:
            cpu: 1m
            memory: 1Mi
...
...

5.查看pod状态，观察到没有生成新的pod

[root@k8s-master01 study]# kubectl get po -n rq-test

NAME                       READY   STATUS        RESTARTS   AGE

test-1-74795ddfbc-6zxft    1/1     Running       0          58m

test-1-74795ddfbc-hhsnd    1/1     Running       0          58m

test-1-74795ddfbc-lxpjh    1/1     Running       0          45m