A limit range, defined by a LimitRange object, enumerates
compute resource
constraints in a project at the pod,
container, image, image stream, and persistent volume claim level, and specifies the amount of resources
that a pod, container, image, image stream, or persistent volume claim can consume.
All resource create and modification requests are evaluated against each
LimitRange object in the project. If the resource violates any of the
enumerated constraints, then the resource is rejected. If the resource does not
set an explicit value, and if the constraint supports a default value, then the
default value is applied to the resource.
apiVersion: "v1"
kind: "LimitRange"
metadata:
name: "core-resource-limits" (1)
spec:
limits:
- type: "Pod"
max:
cpu: "2" (2)
memory: "1Gi" (3)
min:
cpu: "200m" (4)
memory: "6Mi" (5)
- type: "Container"
max:
cpu: "2" (6)
memory: "1Gi" (7)
min:
cpu: "100m" (8)
memory: "4Mi" (9)
default:
cpu: "300m" (10)
memory: "200Mi" (11)
defaultRequest:
cpu: "200m" (12)
memory: "100Mi" (13)
maxLimitRequestRatio:
cpu: "10" (14)-
The name of the limit range object.
-
The maximum amount of CPU that a pod can request on a node across all containers.
-
The maximum amount of memory that a pod can request on a node across all containers.
-
The minimum amount of CPU that a pod can request on a node across all containers.
-
The minimum amount of memory that a pod can request on a node across all containers.
-
The maximum amount of CPU that a single container in a pod can request.
-
The maximum amount of memory that a single container in a pod can request.
-
The minimum amount of CPU that a single container in a pod can request.
-
The minimum amount of memory that a single container in a pod can request.
-
The default amount of CPU that a container will be limited to use if not specified.
-
The default amount of memory that a container will be limited to use if not specified.
-
The default amount of CPU that a container will request to use if not specified.
-
The default amount of memory that a container will request to use if not specified.
-
The maximum amount of CPU burst that a container can make as a ratio of its limit over request.
For more information on how CPU and memory are measured, see Compute Resources.
apiVersion: "v1"
kind: "LimitRange"
metadata:
name: "openshift-resource-limits"
spec:
limits:
- type: openshift.io/Image
max:
storage: 1Gi (1)
- type: openshift.io/ImageStream
max:
openshift.io/image-tags: 20 (2)
openshift.io/images: 30 (3)-
The maximum size of an image that can be pushed to an internal registry.
-
The maximum number of unique image tags per image stream’s spec.
-
The maximum number of unique image references per image stream’s status.
Both core and {product-title} resources can be specified in just one limit range object. They are separated here into two examples for clarity.
Supported Resources:
-
CPU
-
Memory
Supported Constraints:
Per container, the following must hold true if specified:
| Constraint | Behavior |
|---|---|
|
If the configuration defines a |
|
If the configuration defines a |
|
If a configuration defines a For example, if a container has |
Supported Defaults:
Default[resource]-
Defaults
container.resources.limit[resource]to specified value if none. Default Requests[resource]-
Defaults
container.resources.requests[resource]to specified value if none.
Supported Resources:
-
CPU
-
Memory
Supported Constraints:
Across all containers in a pod, the following must hold true:
| Constraint | Enforced Behavior |
|---|---|
|
|
|
|
|
|
Supported Resources:
-
Storage
Resource type name:
-
openshift.io/Image
Per image, the following must hold true if specified:
| Constraint | Behavior |
|---|---|
|
|
|
Warning
|
The image size is not always available in the manifest of an uploaded image. This is especially the case for images built with Docker 1.10 or higher and pushed to a v2 registry. If such an image is pulled with an older Docker daemon, the image manifest will be converted by the registry to schema v1 lacking all the size information. No storage limit set on images will prevent it from being uploaded. The issue is being addressed. |
Supported Resources:
-
openshift.io/image-tags -
openshift.io/images
Resource type name:
-
openshift.io/ImageStream
Per image stream, the following must hold true if specified:
| Constraint | Behavior |
|---|---|
|
|
|
|
Resource openshift.io/image-tags represents unique
image
references. Possible references are an ImageStreamTag, an
ImageStreamImage and a DockerImage. They may be created using commands
oc tag and oc import-image or by using
tag tracking. No distinction
is made between internal and external references. However, each unique reference
tagged in the image stream’s specification is counted just once. It does not
restrict pushes to an internal container registry in any way, but is useful for tag
restriction.
Resource openshift.io/images represents unique image names recorded in image
stream status. It allows for restriction of a number of images that can be
pushed to the internal registry. Internal and external references are not
distinguished.
Supported Resources:
-
Storage
Supported Constraints:
Across all persistent volume claims in a project, the following must hold true:
| Constraint | Enforced Behavior |
|---|---|
|
Min[resource] ⇐ claim.spec.resources.requests[resource] (required) |
|
claim.spec.resources.requests[resource] (required) ⇐ Max[resource] |
{
"apiVersion": "v1",
"kind": "LimitRange",
"metadata": {
"name": "pvcs" (1)
},
"spec": {
"limits": [{
"type": "PersistentVolumeClaim",
"min": {
"storage": "2Gi" (2)
},
"max": {
"storage": "50Gi" (3)
}
}
]
}
}-
The name of the limit range object.
-
The minimum amount of storage that can be requested in a persistent volume claim
-
The maximum amount of storage that can be requested in a persistent volume claim
To apply a limit range to a project, create a limit range object definition on your file system to your desired specifications, then run:
$ oc create -f <limit_range_file> -n <project>
You can view any limit ranges defined in a project by navigating in the web console to the project’s Quota page.
You can also use the CLI to view limit range details:
-
First, get the list of limit ranges defined in the project. For example, for a project called demoproject:
$ oc get limits -n demoproject NAME AGE resource-limits 6d
-
Then, describe the limit range you are interested in, for example the resource-limits limit range:
$ oc describe limits resource-limits -n demoproject Name: resource-limits Namespace: demoproject Type Resource Min Max Default Request Default Limit Max Limit/Request Ratio ---- -------- --- --- --------------- ------------- ----------------------- Pod cpu 200m 2 - - - Pod memory 6Mi 1Gi - - - Container cpu 100m 2 200m 300m 10 Container memory 4Mi 1Gi 100Mi 200Mi - openshift.io/Image storage - 1Gi - - - openshift.io/ImageStream openshift.io/image - 12 - - - openshift.io/ImageStream openshift.io/image-tags - 10 - - -