k8s中可以对namespace来做资源限制，主要通过 ResourceQuota 对象来定义资源配额限制，它可以限制命名空间中某种类型的对象的总数目上限，也可以限制命令空间中的 Pod 可以使用的计算资源的总上限。
首先我们可以检查是否本集群开启了资源配额
kubectl api-resources | grep quota #返回 resourcequotas quota true ResourceQuota
说明已经开启了资源配额
我们下面可以撰写一个例子来实现资源的配额
cat test-quota.yaml apiVersion: v1 kind: ResourceQuota metadata: name: quota namespace: test spec: hard: requests.cpu: "4" requests.memory: "1Gi" requests.storage: "100Gi" pods: "4"
创建资源配额
kubectl apply -f test-quota.yaml
验证方式
cat client.yml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: client
name: client
spec:
replicas: 1
selector:
matchLabels:
app: client
strategy: {}
template:
metadata:
labels:
app: client
spec:
containers:
- image: busybox:1.24.1
name: busybox
args:
- sh
- -c
- "sleep 3600"
resources:
requests:
memory: 2Gi创建测试deployment
kubectl apply -f client.yml -n test
然后我们可以看到POD是pendding状态，于是查看RS副本事件
kubectl -n test describe rs client-9d57dfdf6
返回如下事件信息
Events: Type Reason Age From Message ---- ------ ---- ---- ------- Warning FailedCreate 29s replicaset-controller Error creating: pods "client-9d57dfdf6-9x74f" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 29s replicaset-controller Error creating: pods "client-9d57dfdf6-62kxp" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 29s replicaset-controller Error creating: pods "client-9d57dfdf6-nx9bs" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 29s replicaset-controller Error creating: pods "client-9d57dfdf6-zs9jl" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 28s replicaset-controller Error creating: pods "client-9d57dfdf6-llrdj" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 28s replicaset-controller Error creating: pods "client-9d57dfdf6-25qrk" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 28s replicaset-controller Error creating: pods "client-9d57dfdf6-2tlxl" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 28s replicaset-controller Error creating: pods "client-9d57dfdf6-fdl4j" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 27s replicaset-controller Error creating: pods "client-9d57dfdf6-hjfnf" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=1Gi, limited: requests.memory=1Gi Warning FailedCreate 8s (x4 over 26s) replicaset-controller (combined from similar events): Error creating: pods "client-9d57dfdf6-5xkj7" is forbidden: exceeded quota: quota, requested: requests.memory=2Gi, used: requests.memory=0, limited: requests.memory=1Gi
再尝试创建一个5副本的deployment
cat web.yml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: web
name: web
spec:
replicas: 5
selector:
matchLabels:
app: web
strategy: {}
template:
metadata:
labels:
app: web
spec:
containers:
- image: nginx
name: nginx
resources:
requests:
memory: 100m
cpu: 50m创建测试deployment
kubectl apply -f web.yml -n test
查看创建的副本事件
kubectl -n test describe rs web-584b96b57
返回如下事件信息
Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulCreate 70s replicaset-controller Created pod: web-584b96b57-m9hkv Normal SuccessfulCreate 70s replicaset-controller Created pod: web-584b96b57-24pk5 Normal SuccessfulCreate 70s replicaset-controller Created pod: web-584b96b57-szg9x Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-4ttxz" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Normal SuccessfulCreate 70s replicaset-controller Created pod: web-584b96b57-czr6q Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-jv9mp" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-7vsjh" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-7pbxc" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-sdlgw" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-ksjzx" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-gqk28" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-spczj" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 70s replicaset-controller Error creating: pods "web-584b96b57-8kzvt" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4 Warning FailedCreate 20s (x12 over 69s) replicaset-controller (combined from similar events): Error creating: pods "web-584b96b57-rjkxh" is forbidden: exceeded quota: quota, requested: pods=1, used: pods=4, limited: pods=4
通过以上两个例子可以看到资源限制可以达到我们的要求。