k8s Resource Quotas definition - kubernetes

Question

I want to ignore the resource request that is defined in the service manifest:
resources:
requests:
memory: "512Mi"
cpu: "500m"
limits:
memory: "1024Mi"
cpu: "1000m"
because sometimes developers specifies requests more than they need, and it causes other services to not have enough resources.
I read about Resource Quotas, which I need to define at the namespace level.
My question is: If I define Resource Quotas in the namespace, will the resource request at the service be considered? ignored? or anything else?
Thanks.

Answer 1

What you can use here is a ResourceQuota something like:
apiVersion: v1
kind: ResourceQuota
metadata:
name: mem-cpu
spec:
hard:
cpu: "100m"
memory: "100Mi"
requests.cpu: "500m"
requests.memory: "512Mi"
limits.cpu: "1"
limits.memory: 1Gi
So if you have defined the resource quota (the value which cannot be exceeded by sum of cpu & memory requests respectively) in a namespace to 500m cpu & 512Mi of memory and you worry a single pod might take it up all, you can also define cpu & memory resources in the ResourceQuota (as you see in the example above).
A pod with resource requests:
resources:
limits:
memory: "512Mi"
cpu: "500m"
requests:
memory: "200Mi"
cpu: "200m"
will result in an error:
Error from server (Forbidden): error when creating "so2.yaml": pods "quota-mem-cpu-demo" is forbidden: exceeded quota: mem-cpu, requested: cpu=200m,memory=200Mi, used: cpu=0,memory=0, limited: cpu=100m,memory=100Mi
While this would work:
resources:
limits:
memory: "512Mi"
cpu: "500m"
requests:
memory: "100Mi"
cpu: "100m"
So you can control what resources a user requests.

Answer 2

If I define Resource Quotas in the namespace, will the resource request at the service be considered? ignored? or anything else?
As said in the name, this is a Quota, meaning that the team using the namespace can use up to that quota, but no more. As explained in the documentation, this is enforced at creation time. When a Resource Quota is set, users are required to define resources in the manifests:
If quota is enabled in a namespace for compute resources like cpu and memory, users must specify requests or limits for those values; otherwise, the quota system may reject pod creation.
Hint: Use the LimitRanger admission controller to force defaults for pods that make no compute resource requirements.