Automatic merge from submit-queue
[PHASE 1] Opaque integer resource accounting.
## [PHASE 1] Opaque integer resource accounting.
This change provides a simple way to advertise some amount of arbitrary countable resource for a node in a Kubernetes cluster. Users can consume these resources by including them in pod specs, and the scheduler takes them into account when placing pods on nodes. See the example at the bottom of the PR description for more info.
Summary of changes:
- Defines opaque integer resources as any resource with prefix `pod.alpha.kubernetes.io/opaque-int-resource-`.
- Prevent kubelet from overwriting capacity.
- Handle opaque resources in scheduler.
- Validate integer-ness of opaque int quantities in API server.
- Tests for above.
Feature issue: https://github.com/kubernetes/features/issues/76
Design: http://goo.gl/IoKYP1
Issues:
kubernetes/kubernetes#28312kubernetes/kubernetes#19082
Related:
kubernetes/kubernetes#19080
CC @davidopp @timothysc @balajismaniam
**Release note**:
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```release-note
Added support for accounting opaque integer resources.
Allows cluster operators to advertise new node-level resources that would be
otherwise unknown to Kubernetes. Users can consume these resources in pod
specs just like CPU and memory. The scheduler takes care of the resource
accounting so that no more than the available amount is simultaneously
allocated to pods.
```
## Usage example
```sh
$ echo '[{"op": "add", "path": "pod.alpha.kubernetes.io~1opaque-int-resource-bananas", "value": "555"}]' | \
> http PATCH http://localhost:8080/api/v1/nodes/localhost.localdomain/status \
> Content-Type:application/json-patch+json
```
```http
HTTP/1.1 200 OK
Content-Type: application/json
Date: Thu, 11 Aug 2016 16:44:55 GMT
Transfer-Encoding: chunked
{
"apiVersion": "v1",
"kind": "Node",
"metadata": {
"annotations": {
"volumes.kubernetes.io/controller-managed-attach-detach": "true"
},
"creationTimestamp": "2016-07-12T04:07:43Z",
"labels": {
"beta.kubernetes.io/arch": "amd64",
"beta.kubernetes.io/os": "linux",
"kubernetes.io/hostname": "localhost.localdomain"
},
"name": "localhost.localdomain",
"resourceVersion": "12837",
"selfLink": "/api/v1/nodes/localhost.localdomain/status",
"uid": "2ee9ea1c-47e6-11e6-9fb4-525400659b2e"
},
"spec": {
"externalID": "localhost.localdomain"
},
"status": {
"addresses": [
{
"address": "10.0.2.15",
"type": "LegacyHostIP"
},
{
"address": "10.0.2.15",
"type": "InternalIP"
}
],
"allocatable": {
"alpha.kubernetes.io/nvidia-gpu": "0",
"cpu": "2",
"memory": "8175808Ki",
"pods": "110"
},
"capacity": {
"alpha.kubernetes.io/nvidia-gpu": "0",
"pod.alpha.kubernetes.io/opaque-int-resource-bananas": "555",
"cpu": "2",
"memory": "8175808Ki",
"pods": "110"
},
"conditions": [
{
"lastHeartbeatTime": "2016-08-11T16:44:47Z",
"lastTransitionTime": "2016-07-12T04:07:43Z",
"message": "kubelet has sufficient disk space available",
"reason": "KubeletHasSufficientDisk",
"status": "False",
"type": "OutOfDisk"
},
{
"lastHeartbeatTime": "2016-08-11T16:44:47Z",
"lastTransitionTime": "2016-07-12T04:07:43Z",
"message": "kubelet has sufficient memory available",
"reason": "KubeletHasSufficientMemory",
"status": "False",
"type": "MemoryPressure"
},
{
"lastHeartbeatTime": "2016-08-11T16:44:47Z",
"lastTransitionTime": "2016-08-10T06:27:11Z",
"message": "kubelet is posting ready status",
"reason": "KubeletReady",
"status": "True",
"type": "Ready"
},
{
"lastHeartbeatTime": "2016-08-11T16:44:47Z",
"lastTransitionTime": "2016-08-10T06:27:01Z",
"message": "kubelet has no disk pressure",
"reason": "KubeletHasNoDiskPressure",
"status": "False",
"type": "DiskPressure"
}
],
"daemonEndpoints": {
"kubeletEndpoint": {
"Port": 10250
}
},
"images": [],
"nodeInfo": {
"architecture": "amd64",
"bootID": "1f7e95ca-a4c2-490e-8ca2-6621ae1eb5f0",
"containerRuntimeVersion": "docker://1.10.3",
"kernelVersion": "4.5.7-202.fc23.x86_64",
"kubeProxyVersion": "v1.3.0-alpha.4.4285+7e4b86c96110d3-dirty",
"kubeletVersion": "v1.3.0-alpha.4.4285+7e4b86c96110d3-dirty",
"machineID": "cac4063395254bc89d06af5d05322453",
"operatingSystem": "linux",
"osImage": "Fedora 23 (Cloud Edition)",
"systemUUID": "D6EE0782-5DEB-4465-B35D-E54190C5EE96"
}
}
}
```
After patching, the kubelet's next sync fills in allocatable:
```
$ kubectl get node localhost.localdomain -o json | jq .status.allocatable
```
```json
{
"alpha.kubernetes.io/nvidia-gpu": "0",
"pod.alpha.kubernetes.io/opaque-int-resource-bananas": "555",
"cpu": "2",
"memory": "8175808Ki",
"pods": "110"
}
```
Create two pods, one that needs a single banana and another that needs a truck load:
```
$ kubectl create -f chimp.yaml
$ kubectl create -f superchimp.yaml
```
Inspect the scheduler result and pod status:
```
$ kubectl describe pods chimp
Name: chimp
Namespace: default
Node: localhost.localdomain/10.0.2.15
Start Time: Thu, 11 Aug 2016 19:58:46 +0000
Labels: <none>
Status: Running
IP: 172.17.0.2
Controllers: <none>
Containers:
nginx:
Container ID: docker://46ff268f2f9217c59cc49f97cc4f0f085d5ac0e251f508cc08938601117c0cec
Image: nginx:1.10
Image ID: docker://sha256:82e97a2b0390a20107ab1310dea17f539ff6034438099384998fd91fc540b128
Port: 80/TCP
Limits:
cpu: 500m
memory: 64Mi
pod.alpha.kubernetes.io/opaque-int-resource-bananas: 3
Requests:
cpu: 250m
memory: 32Mi
pod.alpha.kubernetes.io/opaque-int-resource-bananas: 1
State: Running
Started: Thu, 11 Aug 2016 19:58:51 +0000
Ready: True
Restart Count: 0
Volume Mounts: <none>
Environment Variables: <none>
Conditions:
Type Status
Initialized True
Ready True
PodScheduled True
No volumes.
QoS Class: Burstable
Events:
FirstSeen LastSeen Count From SubobjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
9m 9m 1 {default-scheduler } Normal Scheduled Successfully assigned chimp to localhost.localdomain
9m 9m 2 {kubelet localhost.localdomain} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
9m 9m 1 {kubelet localhost.localdomain} spec.containers{nginx} Normal Pulled Container image "nginx:1.10" already present on machine
9m 9m 1 {kubelet localhost.localdomain} spec.containers{nginx} Normal Created Created container with docker id 46ff268f2f92
9m 9m 1 {kubelet localhost.localdomain} spec.containers{nginx} Normal Started Started container with docker id 46ff268f2f92
```
```
$ kubectl describe pods superchimp
Name: superchimp
Namespace: default
Node: /
Labels: <none>
Status: Pending
IP:
Controllers: <none>
Containers:
nginx:
Image: nginx:1.10
Port: 80/TCP
Requests:
cpu: 250m
memory: 32Mi
pod.alpha.kubernetes.io/opaque-int-resource-bananas: 10Ki
Volume Mounts: <none>
Environment Variables: <none>
Conditions:
Type Status
PodScheduled False
No volumes.
QoS Class: Burstable
Events:
FirstSeen LastSeen Count From SubobjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
3m 1s 15 {default-scheduler } Warning FailedScheduling pod (superchimp) failed to fit in any node
fit failure on node (localhost.localdomain): Insufficient pod.alpha.kubernetes.io/opaque-int-resource-bananas
```
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