feat: Add LB exclusion label when deleting node #2518
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Thanks for this! Would you be able to add a test as well within the termination suite_test.go? |
jonathan-innis
previously requested changes
Sep 16, 2022
Added, but I'm not entirely happy with the fact that I'm (ab)using a |
dewjam
reviewed
Sep 20, 2022
Currently, when Karpenter drains and then deletes a Node from the cluster, if that node is registered in a Target Group for an ALB/NLB the corresponding EC2 instance is not removed. This leads to the potential for increased errors when deleting nodes via Karpenter. In order to help resolve this issue, this change adds the well-known `node.kubernetes.io/exclude-from-external-balancers` label, which will case the AWS LB controller to remove the node from the Target Group while Karpenter is draining the node. This is similar to how the AWS Node Termination Handler works (see aws/aws-node-termination-handler#316). In future, Karpenter might be enhanced to be able to wait for a configurable period before deleting the Node and terminating the associated instance as currently there's a race condition between the Pods being drained off of the Node and the EC2 instance being removed from the target group.
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Fixes # N/A
Description
Currently, when Karpenter drains and then deletes a Node from the
cluster, if that node is registered in a Target Group for an ALB/NLB the
corresponding EC2 instance is not removed. This leads to the potential
for increased errors when deleting nodes via Karpenter.
In order to help resolve this issue, this change adds the well-known
node.kubernetes.io/exclude-from-external-balancerslabel, which willcase the AWS LB controller to remove the node from the Target Group
while Karpenter is draining the node. This is similar to how the AWS
Node Termination Handler works (see
aws/aws-node-termination-handler#316).
In future, Karpenter might be enhanced to be able to wait for a
configurable period before deleting the Node and terminating the
associated instance as currently there's a race condition between the
Pods being drained off of the Node and the EC2 instance being removed
from the target group.
How was this change tested?
Does this change impact docs?
Release Note
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.