How to retrieve node-pool size from a k8s cluster? - kubernetes

Question

I couldn't find useful information from:
gcloud container clusters describe CLUSTER_NAME
or from
gcloud container node-pools describe POOL_NAME --cluster CLUSTER_NAME
It is easy to scale up/down using gcloud tool though:
gcloud container clusters resize [CLUSTER_NAME] --node-pool [POOL_NAME] \
--size [SIZE]
But how can I know beforehand what is the size of my node-pool?

Answer 1

I do not agree with the current answer because it only gives the total size of the cluster.
The question is about node-pools. I actually needed to find out the size of a pool so I give you my best shot after many hours of searching and thinking.
read -p 'Cluster name: ' CLUSTER_NAME
read -p 'Pool name: ' POOL_NAME
gcloud compute instance-groups list \
| grep "^gke-$CLUSTER_NAME-$POOL_NAME" \
| awk '{print $6}';
The gcloud command returns 6 columns: 1-name, 6-group-size.
The name of the instance group is predictable which lets me filter by that line with grep.
Lastly, select the 6th column.
Hope this helps someone else save some time.
For some reason I overlooked the not-so-obviuos from Migrating workloads to different machine types
kubectl get nodes -l cloud.google.com/gke-nodepool=$POOL_NAME -o=name \
| wc -l

Answer 2

You should use the following command:
gcloud container clusters describe <cluster name> --zone <zone-cluster>
Check for the field currentNodeCount

Answer 3

building on top of #hanzo2001 answer - something like this will probably reflect what you need:
kubectl get nodes -L cloud.google.com/gke-nodepool | grep -v GKE-NODEPOOL | awk '{print $6}' | sort | uniq -c | sort -r
16 n2-standard-4-pool
2 preempt-custom-6
2 default-pool

Answer 4

There is one (often overlooked/hidden) feature of the gcloud - filters and formatters. These can help you to get the requested information without further awk/grep -ing.
Get the current size/node count of a specific node-pool:
gcloud compute instance-groups list \
--filter "name:gke-<cluster>-<nodepool>-*" \
--format 'value(size)'
Example for cluster test and node-pool default-pool:
$ gcloud compute instance-groups list --filter "name:gke-test-default-pool-*" \
--format 'value(size)'
2
Get the current size/node count of every node-pool in the cluster you can further use:
CLUSTER=test
for nodepool in $(gcloud container node-pools list --cluster $CLUSTER --format="value(name)"); do
echo -n "${nodepool}: "
gcloud compute instance-groups list \
--filter "name:gke-${CLUSTER}-${nodepool}-*" \
--format 'value(size)'
done
Other relevant resources:
gcloud topic filters - gcloud filters reference
gcloud topic formats - gcloud formats reference
GCP blog post on filtering and formatting