GKE Nodepool Add Labels Without overwriting existing labelsFri 07 April 2023 | Last updated on Sat 08 April 2023
GKE has a feature to add node labels to all nodes in the nodepool. GKE will add the label to both the nodes already running in the cluster and also to newly added nodes.
You can use the feature like this:
gcloud container node-pools update my-node-pool \ --cluster my-cluster --labels sam=test
That would add the label
sam: test all your nodepools. The docs however do mention the
following: "The label update overwrites any existing labels on the node pool. If the
node pool has existing labels that you want to keep, you must include those
labels along with any new labels that you want to add."
Well that's lame. But worry not. It's relatively easy to script this with a few lines of bash.
Create a file named
gke-nodepool-add-label.sh with the following content:
#!/usr/bin/env bash set -x CLUSTER_NAME="$1" POOL_NAME="$2" NEW_LABEL="$3" LABELS=$(gcloud container node-pools describe $POOL_NAME \ --cluster $CLUSTER_NAME --format "get(config.labels)" | tr ";" ",") echo "Current labels: $LABELS" gcloud container node-pools update $POOL_NAME \ --cluster $CLUSTER_NAME --node-labels="$LABELS,$NEW_LABEL"
Make the file executable:
chmod +x gke-nodepool-add-label.sh
Now you can run the script like this to add a label without overwriting existing labels:
./gke-nodepool-add-label.sh my-cluster my-nodepool sam=test