Define resource quota objects per namespace. you can set maximum compute resources per namespace and also define number of objects to be deployed per namespace. follow the below samples

apiVersion: v1
kind: ResourceQuota
metadata:
  name: mem-cpu-demo
  namespace: quota-mem-cpu-example
spec:
  hard:
    requests.cpu: "1"
    requests.memory: 1Gi
    limits.cpu: "2"
    limits.memory: 2Gi
----
The ResourceQuota places these requirements on the quota-mem-cpu-example namespace:

Every Container must have a memory request, memory limit, cpu request, and cpu limit.
The memory request total for all Containers must not exceed 1 GiB.
The memory limit total for all Containers must not exceed 2 GiB.
The CPU request total for all Containers must not exceed 1 cpu.
The CPU limit total for all Containers must not exceed 2 cpu.

similarly define object quota

apiVersion: v1
kind: ResourceQuota
metadata:
  name: object-quota-demo
  namespace: quota-object-example
spec:
  hard:
    persistentvolumeclaims: "1"
    services.loadbalancers: "2"
    services.nodeports: "0"


Which implies that there can be at most one PersistentVolumeClaim, at most two Services of type LoadBalancer, and no Services of type NodePort.

reference: https://kubernetes.io/docs/tasks/administer-cluster/quota-api-object/

This can be accomplished via a ResourceQuota on the given namespace.

From the docs:

A resource quota, defined by a ResourceQuota object, provides constraints that limit aggregate resource consumption per namespace. It can limit the quantity of objects that can be created in a namespace by type, as well as the total amount of compute resources that may be consumed by resources in that project.

A resource quota is defined like so (from the k8s admin docs):

apiVersion: v1
kind: ResourceQuota
metadata:
  name: mem-cpu-demo
spec:
  hard:
    requests.cpu: "1"
    requests.memory: 1Gi
    limits.cpu: "2"
    limits.memory: 2Gi

Note: This information comes from the k8s v1.16 documentation