资源配额 LimitRange
默认情况下，K8s集群上的容器对计算资源没有任何限制，可能会导致个别容器资源过大导致影响其他容器正常工作，这时可以使用LimitRange定义容器默认CPU和内存请求值或者最大上限。(默认是使用宿主机上面所有的资源)
在哪个命名空间下面创建，那么就是应用在哪个命名空间。
LimitRange限制维度：
? 限制容器配置requests.cpu/memory，limits.cpu/memory的最小、最大值
? 限制容器配置requests.cpu/memory，limits.cpu/memory的默认值
? 限制PVC配置requests.storage的最小、最大值
限制创建pod设置request和limit，最小得超过最小值，但是不能超过最大值，就是最小和最大的限
制。下面是针对于pod下面的每一个容器的。
[root@master limitrnage]# kubectl apply -f test1.yaml
limitrange/cpu-memory-min-max created
[root@master limitrnage]# cat test1.yaml
apiVersion: v1
kind: LimitRange
metadata:name: cpu-memory-min-maxnamespace: dev1
spec:limits:- max: #容器能够设置limit最大值cpu: 1memory: 1Gimin: #容器能够设置request最小值cpu: 200m memory: 200Mitype: Container[root@master limitrnage]# kubectl get limits -n dev1
NAME CREATED AT
cpu-memory-min-max 2021-07-02T01:01:16Z
[root@master limitrnage]# kubectl describe limits cpu-memory-min-max -n dev1
Name: cpu-memory-min-max
Namespace: dev1
Type Resource Min Max Default Request Default Limit Max Limit/Request Ratio
---- -------- --- --- --------------- ------------- -----------------------
Container cpu 200m 1 1 1 -
Container memory 200Mi 1Gi 1Gi 1Gi 测试request，小于request
[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginxresources:requests:cpu: 100mmemory: 100Mi[root@master limitrnage]# kubectl apply -f pod.yaml
Error from server (Forbidden): error when creating "pod.yaml": pods "web" is forbidden: [minimum cpu usage per Container is 200m, but request is 100m, minimum memory usage per Container is 200Mi, but request is 100Mi]request值大于limit
[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginxresources:requests:cpu: 1500mmemory: 400Mi[root@master limitrnage]# kubectl apply -f pod.yaml
The Pod "web" is invalid: spec.containers[0].resources.requests: Invalid value: "1500m": must be less than or equal to cpu limit测试limit，request值正常，但是limit的值不符合要求，超过CPU限制
[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginxresources:requests:cpu: 300mmemory: 400Milimits:cpu: 2memory: 1Gi [root@master limitrnage]# kubectl apply -f pod.yaml
Error from server (Forbidden): error when creating "pod.yaml": pods "web" is forbidden: maximum cpu usage per Container is 1, but limit is 2超过mem限制
[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginxresources:requests:cpu: 300mmemory: 400Milimits:cpu: 500mmemory: 2Gi [root@master limitrnage]# kubectl apply -f pod.yaml
Error from server (Forbidden): error when creating "pod.yaml": pods "web" is forbidden: maximum memory usage per Container is 1Gi, but limit is 2Gi计算资源默认值限制
不指定request和limit的值的时候，会发生什么变化。
#在设置的上面的limit最大值和request最小值的的时候，如果创建容器不指定其resources字段，默认以limit最大值进行分配[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginx[root@master limitrnage]# kubectl apply -f pod.yaml
pod/web created
[root@master limitrnage]# kubectl describe pod web -n dev1
Name: web
Namespace: dev1
Priority: 0
......................................Limits: #可以看到是以最大值进行分配cpu: 1memory: 1GiRequests:cpu: 1memory: 1Gi所以还要设置一个默认值，否则默认值会比较大，因为参考的是最大值。
[root@master limitrnage]# cat test1.yaml
apiVersion: v1
kind: LimitRange
metadata:name: cpu-memory-min-maxnamespace: dev1
spec:limits:- max: cpu: 1memory: 1Gimin: cpu: 200m memory: 200MidefaultRequest:cpu: 300mmemory: 300Mitype: Container [root@master limitrnage]# kubectl describe limits cpu-memory-min-max -n dev1
Name: cpu-memory-min-max
Namespace: dev1
Type Resource Min Max Default Request Default Limit Max Limit/Request Ratio
---- -------- --- --- --------------- ------------- -----------------------
Container cpu 200m 1 300m 1 -
Container memory 200Mi 1Gi 300Mi 1Gi -[root@master limitrnage]# cat pod.yaml
apiVersion: v1
kind: Pod
metadata:name: webnamespace: dev1
spec:containers:- image: nginxname: nginx
[root@master limitrnage]# kubectl apply -f pod.yaml
pod/web created
[root@master limitrnage]# kubectl get pod -n dev1
NAME READY STATUS RESTARTS AGE
web 1/1 Running 0 19s
[root@master limitrnage]# kubectl describe pod web -n dev1
Name: web
Namespace: dev1
.............................................Limits:cpu: 1memory: 1GiRequests:cpu: 300mmemory: 300Mi这里最好将默认最大值limit也限制一下，要不然是按照最大值限制的。
存储资源最大、最小限制：pvc申请超过10G会拒绝，低于1G也会拒绝，这个范围就是1-10G
[root@master limitrnage]# kubectl describe limits storage-min-max -n dev1
Name: storage-min-max
Namespace: dev1
Type Resource Min Max Default Request Default Limit Max Limit/Request Ratio
---- -------- --- --- --------------- ------------- -----------------------
PersistentVolumeClaim storage 1Gi 10Gi - - -
[root@master limitrnage]# cat test2.yaml
apiVersion: v1
kind: LimitRange
metadata:name: storage-min-maxnamespace: dev1
spec:limits:- type: PersistentVolumeClaimmax:storage: 10Gimin:storage: 1Gi[root@master limitrnage]# cat pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:name: nfs-pvcnamespace: dev1
spec:accessModes:- ReadWriteManyresources:requests:storage: 15GistorageClassName: nfs[root@master limitrnage]# kubectl apply -f pvc.yaml
Error from server (Forbidden): error when creating "pvc.yaml": persistentvolumeclaims "nfs-pvc" is forbidden: maximum storage usage per PersistentVolumeClaim is 10Gi, but request is 15Gi