121 lines
3.5 KiB
Markdown
121 lines
3.5 KiB
Markdown
---
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title: Assign Pods to Nodes using Node Affinity
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min-kubernetes-server-version: v1.10
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content_template: templates/task
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weight: 120
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---
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{{% capture overview %}}
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This page shows how to assign a Kubernetes Pod to a particular node using Node Affinity in a
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Kubernetes cluster.
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{{% /capture %}}
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{{% capture prerequisites %}}
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{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
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{{% /capture %}}
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{{% capture steps %}}
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## Add a label to a node
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1. List the nodes in your cluster, along with their labels:
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```shell
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kubectl get nodes --show-labels
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```
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The output is similar to this:
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```shell
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NAME STATUS ROLES AGE VERSION LABELS
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worker0 Ready <none> 1d v1.13.0 ...,kubernetes.io/hostname=worker0
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worker1 Ready <none> 1d v1.13.0 ...,kubernetes.io/hostname=worker1
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worker2 Ready <none> 1d v1.13.0 ...,kubernetes.io/hostname=worker2
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```
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1. Chose one of your nodes, and add a label to it:
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```shell
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kubectl label nodes <your-node-name> disktype=ssd
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```
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where `<your-node-name>` is the name of your chosen node.
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1. Verify that your chosen node has a `disktype=ssd` label:
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```shell
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kubectl get nodes --show-labels
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```
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The output is similar to this:
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```
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NAME STATUS ROLES AGE VERSION LABELS
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worker0 Ready <none> 1d v1.13.0 ...,disktype=ssd,kubernetes.io/hostname=worker0
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worker1 Ready <none> 1d v1.13.0 ...,kubernetes.io/hostname=worker1
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worker2 Ready <none> 1d v1.13.0 ...,kubernetes.io/hostname=worker2
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```
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In the preceding output, you can see that the `worker0` node has a
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`disktype=ssd` label.
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## Schedule a Pod using required node affinity
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This manifest describes a Pod that has a `requiredDuringSchedulingIgnoredDuringExecution` node affinity,`disktype: ssd`.
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This means that the pod will get scheduled only on a node that has a `disktype=ssd` label.
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{{< codenew file="pods/pod-nginx-required-affinity.yaml" >}}
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1. Apply the manifest to create a Pod that is scheduled onto your
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chosen node:
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```shell
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kubectl apply -f https://k8s.io/examples/pods/pod-nginx-required-affinity.yaml
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```
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1. Verify that the pod is running on your chosen node:
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```shell
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kubectl get pods --output=wide
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```
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The output is similar to this:
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```
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NAME READY STATUS RESTARTS AGE IP NODE
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nginx 1/1 Running 0 13s 10.200.0.4 worker0
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```
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## Schedule a Pod using preferred node affinity
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This manifest describes a Pod that has a `preferredDuringSchedulingIgnoredDuringExecution` node affinity,`disktype: ssd`.
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This means that the pod will prefer a node that has a `disktype=ssd` label.
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{{< codenew file="pods/pod-nginx-preferred-affinity.yaml" >}}
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1. Apply the manifest to create a Pod that is scheduled onto your
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chosen node:
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```shell
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kubectl apply -f https://k8s.io/examples/pods/pod-nginx-preferred-affinity.yaml
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```
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1. Verify that the pod is running on your chosen node:
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```shell
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kubectl get pods --output=wide
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```
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The output is similar to this:
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```
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NAME READY STATUS RESTARTS AGE IP NODE
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nginx 1/1 Running 0 13s 10.200.0.4 worker0
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```
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{{% /capture %}}
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{{% capture whatsnext %}}
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Learn more about
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[Node Affinity](/docs/concepts/configuration/assign-pod-node/#node-affinity).
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{{% /capture %}}
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