GCP Google Kubernetes Engine Kubernetes Startup Probes

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¶

Implement Startup Probe and Test it

Step-02: Understand Startup Probe¶

Sometimes, you have to deal with legacy applications that might require an additional startup time on their first initialization.
The application will have a maximum of 5 minutes (30 * 10 = 300s) to finish its startup.
Once the startup probe has succeeded once, the liveness probe takes over to provide a fast response to container deadlocks.
If the startup probe never succeeds, the container is killed after 300s and subject to the pod's restartPolicy.

Step-03: Review Startup Probe YAML¶

File Name: 05-UserMgmtWebApp-Deployment.yaml

          # Startup Probe - Wait for 5 minutes till the application starts            
          startupProbe:
            httpGet:
              path: /login
              port: 8080
            initialDelaySeconds: 60              
            periodSeconds: 10            
            failureThreshold: 30  # The application will have a maximum of 5 minutes (30 * 10 = 300s) to finish its startup.
            successThreshold: 1 # Default value

Step-04: Deploy Kubernetes Manifests¶

# Deploy Kubernetes Manifests
kubectl apply -f kube-manifests-startup-probe

# List Pods
kubectl get pods
Observation:

# List Services
kubectl get svc

# Access Application
http://<LB-IP>
Username: admin101
Password: password101

Step-05: Clean-Up¶

# Delete Kubernetes Resources
kubectl delete -f kube-manifests-startup-probe