Please refer to this [doc](https://github.com/GoogleCloudPlatform/kubernetes/blob/620af168920b773ade28e27211ad684903a1db21/docs/design/admission_control_limit_range.md#kubectl).
Limit Range
========================================
By default, pods run with unbounded CPU and memory limits. This means that any pod in the
system will be able to consume as much CPU and memory on the node that executes the pod.
Users may want to impose restrictions on the amount of resource a single pod in the system may consume
for a variety of reasons.
For example:
1. Each node in the cluster has 2GB of memory. The cluster operator does not want to accept pods
that require more than 2GB of memory since no node in the cluster can support the requirement. To prevent a
pod from being permanently unscheduled to a node, the operator instead chooses to reject pods that exceed 2GB
of memory as part of admission control.
2. A cluster is shared by two communities in an organization that runs production and development workloads
respectively. Production workloads may consume up to 8GB of memory, but development workloads may consume up
to 512MB of memory. The cluster operator creates a separate namespace for each workload, and applies limits to
each namespace.
3. Users may create a pod which consumes resources just below the capacity of a machine. The left over space
may be too small to be useful, but big enough for the waste to be costly over the entire cluster. As a result,
the cluster operator may want to set limits that a pod must consume at least 20% of the memory and cpu of their
average node size in order to provide for more uniform scheduling and to limit waste.
This example demonstrates how limits can be applied to a Kubernetes namespace to control
min/max resource limits per pod. In addition, this example demonstrates how you can
apply default resource limits to pods in the absence of an end-user specified value.
For a detailed description of the Kubernetes resource model, see [Resources](https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/resources.md)
Step 0: Prerequisites
-----------------------------------------
This example requires a running Kubernetes cluster. See the [Getting Started guides](../../docs/getting-started-guides) for how to get started.
Change to the `<kubernetes>/examples/limitrange` directory if you're not already there.
Step 1: Create a namespace
-----------------------------------------
This example will work in a custom namespace to demonstrate the concepts involved.
Let's create a new namespace called limit-example:
