GCP Google Kubernetes Engine Cluster Autoscaling

Step-00: Pre-requisites¶

Verify if GKE Cluster is created

Verify if kubeconfig for kubectl is configured in your local terminal

# Configure kubeconfig for kubectl
gcloud container clusters get-credentials <CLUSTER-NAME> --region <REGION> --project <PROJECT>

# Replace Values CLUSTER-NAME, REGION, PROJECT
gcloud container clusters get-credentials standard-cluster-private-1 --region us-central1 --project kdaida123

# List Kubernetes Nodes
kubectl get nodes

Step-01: Introduction¶

Test Cluster Autoscaler feature

Step-02: Verify Cluster Autoscaler enabled for Node Pool¶

Go to Kubernetes Engine -> standard-cluster-private-1 -> NODES Tab -> default-pool -> Click on Edit
Check Enable cluster autoscaler
Size limits type
Check Per zone limits
Minimum number of nodes (per zone): 0
Maximum number of nodes (per zone): 3

Step-03: Verify the 5th Pod from previous Demo is still in Pending State¶

# List Pods
kubectl get pods

# Describe Pod (PENDING POD)
kubectl describe pod <PENDING-POD-NAME>
Observation:
1. Verify the pod events where we can find the autoscaling event triggered

# List Kubernetes Nodes
kubectl get nodes 
Observation:
1. Nodes in NodePools will be increased from 3 to 4 (2 per zone max we configured)

# Scale-In the demo application to 1 pod
kubectl get pods
kubectl get nodes 
kubectl scale --replicas=1 deploy myapp1-deployment 
kubectl get pods

# List Kubernetes Nodes
kubectl get nodes
1. Nodes in NodePools will be decreased from 4 to 3 (Wait for 10 minutes for Nodes Scale-In)

Step-04: Clean-up¶

# Delete Kubernetes Resources
kubectl delete -f kube-manifests