Assigning Pods to Nodes

caution

This is internal documentation. This document can be used only if it was recommended by the Support Team.

Prerequisites

• The kubectl command-line tool
• Access to a Kubernetes cluster with installed Release

Tested with:

• xl-release 22.2.0-x
• xl-cli 10.3.9
• Azure cluster

Intro

All running pods, deployed with xl-release, have no defined:

• pod tolerations
• node labels in the nodeSelector
• node (anti-)affinity

If you need to apply on pods custom scheduling to the appropriate node you can use following files to change that in your operator package:

1. digitalai-release/kubernetes/dairelease_cr.yaml

   In the file search all places where is tolerations: [] or nodeSelector: {} and add appropriate values there.

2. digitalai-release/kubernetes/template/deployment.yaml

   In the file add to the path spec.template.spec appropriate values with tolerations: [] or nodeSelector: {}.

In next sections we will display few cases that could be applied.

Removing Pods from Specific Node

If you need that specific node should not run any xl-release pods, you can apply taint to that node with effect NoExecute, for example:

❯ kubectl taint nodes node_name key1=value1:NoExecute

All pods that do not have that specific toleration will be immediately removed from nodes with that specific taint.

Assigning XLR Pods to the Specific Nodes

If you need to have just XLR pods, and no other pod, on the specific node you need to do following, for example:

1. Add to nodes specific taints that will remove all other pods without same tolerations:

❯ kubectl taint nodes node_name app=dai:NoExecute

2. Add label to the same nodes so XLR when deployed use just that specific nodes:

❯ kubectl label nodes node_name app_label=dai_label

3. In the digitalai-release/kubernetes/dairelease_cr.yaml update all places with tolerations:

tolerations:
- key: "app"
  operator: "Equal"
  value: "dai"
  effect: "NoExecute"

And update all places with nodeSelector:

nodeSelector:
  app_label: dai_label

4. In the digitalai-release/kubernetes/template/deployment.yaml add following lines under spec.template.spec:

tolerations:
- key: "app"
  operator: "Equal"
  value: "dai"
  effect: "NoExecute"
nodeSelector:
  app_label: dai_label