> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Demo Creating node taints on a GKE cluster

> This tutorial teaches how to control pod placement in GKE using node taints and tolerations.

In this tutorial, you’ll learn how to control pod placement in Google Kubernetes Engine (GKE) by applying **node taints** and **tolerations**. We’ll cover:

1. Creating a GKE cluster with a tainted default node pool
2. Adding an untainted node pool
3. Updating node pool taints post‐creation
4. Provisioning a dedicated node pool with a unique taint
5. Deploying pods **with** and **without** tolerations to observe scheduling behavior
6. Removing a taint and watching pods land on the default pool

***

## Prerequisites

* Google Cloud SDK installed or access to [Cloud Shell](https://cloud.google.com/shell).
* Authentication configured (`gcloud auth login`).

Set your project and compute zone:

```bash theme={null}
gcloud config set project YOUR_PROJECT_ID
gcloud config set compute/zone us-west1-a
```

***

## Node Pools & Taints Overview

| Node Pool                    | Taint                                | Purpose                 |
| ---------------------------- | ------------------------------------ | ----------------------- |
| default                      | `function=research:PreferNoSchedule` | Research workloads      |
| gke-deep-dive-pool           | *none*                               | Shared/utility services |
| gke-deep-dive-pool (updated) | `function=shared:NoSchedule`         | Shared services         |
| gke-deep-dive-pool-dedicated | `dedicated=dev:NoExecute`            | Development workloads   |

***

## 1. Create a Cluster with a Tainted Default Node Pool

```bash theme={null}
gcloud container clusters create gke-deep-dive \
  --num-nodes=1 \
  --disk-type=pd-standard \
  --disk-size=10 \
  --node-taints=function=research:PreferNoSchedule
```

<Callout icon="lightbulb" color="#1CB2FE">
  Cluster provisioning can take **10–15 minutes**. Use `gcloud container operations list` to track progress.
</Callout>

### Verify the Taint

```bash theme={null}
kubectl get nodes
kubectl describe node <NODE_NAME> | grep -A1 "Taints"
```

Expected output:

```text theme={null}
Taints:
  function=research:PreferNoSchedule
```

***

## 2. Add an Untainted Node Pool

New node pools inherit **no** taints by default. Create one:

```bash theme={null}
gcloud container node-pools create gke-deep-dive-pool \
  --cluster=gke-deep-dive \
  --num-nodes=1 \
  --disk-type=pd-standard \
  --disk-size=10
```

Verify:

```bash theme={null}
kubectl get nodes
kubectl describe node <NEW_NODE_NAME> | grep -A1 "Taints"
```

Expected:

```text theme={null}
Taints: <none>
```

***

## 3. Update a Node Pool’s Taint

Apply a new taint to the existing pool:

```bash theme={null}
gcloud beta container node-pools update gke-deep-dive-pool \
  --cluster=gke-deep-dive \
  --node-taints=function=shared:NoSchedule
```

Verify:

```bash theme={null}
kubectl describe node <NEW_NODE_NAME> | grep -A1 "Taints"
```

Expected:

```text theme={null}
Taints:
  function=shared:NoSchedule
```

***

## 4. Create a Dedicated Node Pool with a Different Taint

Provision a third pool for development workloads:

```bash theme={null}
gcloud container node-pools create gke-deep-dive-pool-dedicated \
  --cluster=gke-deep-dive \
  --num-nodes=1 \
  --disk-type=pd-standard \
  --disk-size=10 \
  --node-taints=dedicated=dev:NoExecute
```

***

## 5. Deploy a Pod That Tolerates the Shared Taint

Save as `shared-pod.yaml`:

```yaml theme={null}
apiVersion: v1
kind: Pod
metadata:
  name: shared-pod
spec:
  containers:
  - name: nginx
    image: nginx
  tolerations:
  - key: "function"
    operator: "Equal"
    value: "shared"
    effect: "NoSchedule"
```

Apply and inspect scheduling:

```bash theme={null}
kubectl apply -f shared-pod.yaml
kubectl get pods -o wide
```

The pod should land on the node with `function=shared:NoSchedule`.

***

## 6. Remove the Taint from the Default Node Pool

First, identify the default node:

```bash theme={null}
kubectl get nodes
```

Then remove its taint:

```bash theme={null}
kubectl taint nodes <DEFAULT_NODE_NAME> function-
```

Verify:

```bash theme={null}
kubectl describe node <DEFAULT_NODE_NAME> | grep -A1 "Taints"
```

Expected:

```text theme={null}
Taints: <none>
```

<Callout icon="triangle-alert" color="#FF6B6B">
  Removing taints allows **all** untolerated pods to schedule on this node pool. Plan accordingly.
</Callout>

***

## 7. Deploy a Pod Without Any Toleration

Save as `dedicated-pod.yaml`:

```yaml theme={null}
apiVersion: v1
kind: Pod
metadata:
  name: dedicated-pod
spec:
  containers:
  - name: nginx
    image: nginx
```

Apply and observe:

```bash theme={null}
kubectl apply -f dedicated-pod.yaml
kubectl get pods
```

Since the default pool is now untainted, `dedicated-pod` transitions from `Pending` to `Running` on the default node.

***

Congratulations! You’ve successfully used **node taints** and **tolerations** to control pod placement in a GKE cluster.

***

## Links and References

* [GKE Taints and Tolerations](https://cloud.google.com/kubernetes-engine/docs/how-to/node-taints)
* [Kubernetes Scheduling Concepts](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/)
* [kubectl Cheat Sheet](https://kubernetes.io/docs/reference/kubectl/cheatsheet/)

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