Taints for EKS Nodes

Manage taints for EKS nodes in the DuploCloud Portal

Taints influence Kubernetes workload scheduling by marking nodes with specific conditions that certain Pods must tolerate to be scheduled on those nodes. Taints ensure that only compatible workloads run on a node, which can be useful for restricting access to certain resources, isolating environments, or managing resource usage.

Kubernetes can automatically add taints to nodes, for example, when a node becomes unreachable or has health issues, Kubernetes may apply a taint to prevent new workloads from being scheduled there. Certain workloads might require a specific configuration, so taints help ensure only compatible resources are used.

In addition to these automatic taints, you can control workload distribution by manually adding taints to EKS nodes or agent pools in the DuploCloud Portal.

Managing Taints on EKS Nodes

In DuploCloud, you can assign Kubernetes taints to EKS worker nodes to control how workloads are scheduled. Taints can be added during node creation or managed later from the node's detail page.

Adding Taints During Node Creation

1. When Adding a Host in the DuploCloud Portal, click the Add Taint button at the bottom right of the Advanced Options section. The Add Taint pane displays.

   

   The Add Taint pane in the DuploCloud Portal
2. Complete the following fields:

Key	Identify the taint condition. Example values: dedicated, testing.
Value	Provide additional context for the key. Example values: dev, staging, prod.
Effect	Specify the action taken if a Pod does not tolerate the taint: • NoSchedule: Prevents the Pod from being scheduled on the node unless it tolerates the taint. • PreferNoSchedule: Kubernetes avoids scheduling the Pod on this node if possible, but may still allow it. • NoExecute: Immediately evicts existing Pods that don’t tolerate the taint and blocks new ones.

1. Click Add Taint. The taint is added to the node.

Adding Taints After Node Creation

To add a taint to an existing node:

1. Navigate to Kubernetes -> Nodes

2. Select the correct tab (EC2, ASG, etc.).

3. Click the Name of the node to open its details page.

4. Select the Taints tab.

5. Click Add. The Add Taint pane displays.

6. Enter the Key, Value, and Effect.

7. Click Add Taint. The new taint will appear in the list immediately.

Viewing Taints

You can view the taints applied to a node from the Status column in the Nodes list, or from the Taints tab on the Node details page.

Viewing Taints from the Node List

1. Navigate to Kubernetes -> Nodes.

2. Look for the Tainted status under the Status column.

3. Click on the Tainted status for any node to open a list of taints applied to that node.

Viewing Taints from the Node Details Page

1. Navigate to Kubernetes -> Nodes.

2. Click on the node in the NAME column.

3. Select the Taints tab. The Taints tab displays the key, value, and effect of each taint applied to the node.

If you're familiar with kubectl, you can also manage taints from the command line. See the official kubectl taint command reference for syntax and usage examples.

Editing or Deleting Taints

1. Navigate to Kubernetes -> Nodes.

2. Click on the node in the NAME column.

3. Select the Taints tab.

4. Click the menu icon () next to the taint you want to manage.

5. Select Edit to modify the taint Key, Value, or Effect of the taint or Delete to remove the taint from the node.

The Taints tab on the EC2 node details page