GCP Google Kubernetes Engine Ingress Custom Health Check

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, ZONE, PROJECT
gcloud container clusters get-credentials standard-cluster-private-1 --region us-central1 --project kdaida123

Step-01: Introduction¶

Ingress Context Path based Routing
Ingress Custom Health Checks for each application using Kubernetes Readiness Probes
App1 Health Check Path: /app1/index.html
App2 Health Check Path: /app2/index.html
App3 Health Check Path: /index.html

Step-02: 01-Nginx-App1-Deployment-and-NodePortService.yaml¶

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1-nginx-deployment
  labels:
    app: app1-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app1-nginx
  template:
    metadata:
      labels:
        app: app1-nginx
    spec:
      containers:
        - name: app1-nginx
          image: stacksimplify/kube-nginxapp1:1.0.0
          ports:
            - containerPort: 80
          # Readiness Probe (https://cloud.google.com/kubernetes-engine/docs/concepts/ingress#def_inf_hc)             
          readinessProbe:
            httpGet:
              scheme: HTTP
              path: /app1/index.html
              port: 80
            initialDelaySeconds: 10
            periodSeconds: 15
            timeoutSeconds: 5

Step-03: 02-Nginx-App2-Deployment-and-NodePortService.yaml¶

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app2-nginx-deployment
  labels:
    app: app2-nginx 
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app2-nginx
  template:
    metadata:
      labels:
        app: app2-nginx
    spec:
      containers:
        - name: app2-nginx
          image: stacksimplify/kube-nginxapp2:1.0.0
          ports:
            - containerPort: 80
          # Readiness Probe (https://cloud.google.com/kubernetes-engine/docs/concepts/ingress#def_inf_hc)             
          readinessProbe:
            httpGet:
              scheme: HTTP
              path: /app2/index.html
              port: 80
            initialDelaySeconds: 10
            periodSeconds: 15
            timeoutSeconds: 5

Step-04: 03-Nginx-App3-Deployment-and-NodePortService.yaml¶

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app3-nginx-deployment
  labels:
    app: app3-nginx 
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app3-nginx
  template:
    metadata:
      labels:
        app: app3-nginx
    spec:
      containers:
        - name: app3-nginx
          image: stacksimplify/kubenginx:1.0.0
          ports:
            - containerPort: 80
          # Readiness Probe (https://cloud.google.com/kubernetes-engine/docs/concepts/ingress#def_inf_hc)            
          readinessProbe:
            httpGet:
              scheme: HTTP
              path: /index.html
              port: 80
            initialDelaySeconds: 10
            periodSeconds: 15
            timeoutSeconds: 5

Step-05: 04-Ingress-Custom-Healthcheck.yaml¶

NO CHANGES FROM CONTEXT PATH ROUTING DEMO other than Ingress Service name ingress-custom-healthcheck

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-custom-healthcheck
  annotations:
    # External Load Balancer
    kubernetes.io/ingress.class: "gce"  
spec: 
  defaultBackend:
    service:
      name: app3-nginx-nodeport-service
      port:
        number: 80                            
  rules:
    - http:
        paths:           
          - path: /app1
            pathType: Prefix
            backend:
              service:
                name: app1-nginx-nodeport-service
                port: 
                  number: 80
          - path: /app2
            pathType: Prefix
            backend:
              service:
                name: app2-nginx-nodeport-service
                port: 
                  number: 80
#          - path: /
#            pathType: Prefix
#            backend:
#              service:
#                name: app3-nginx-nodeport-service
#                port: 
#                  number: 80

Step-06: Deploy kube-manifests and verify¶

# Deploy Kubernetes manifests
kubectl apply -f kube-manifests

# List Pods
kubectl get pods

# List Services
kubectl get svc

# List Ingress Load Balancers
kubectl get ingress

# Describe Ingress and view Rules
kubectl describe ingress ingress-custom-healthcheck

Step-07: Verify Health Checks¶

Go to Load Balancing -> Click on LB
DETAILS TAB
Backend services -> First Backend -> Click on Health Check Link
OR
Go to Compute Engine -> Instance Groups -> Health Checks
Review all 3 Health Checks and their Paths
App1 Health Check Path: /app1/index.html
App2 Health Check Path: /app2/index.html
App3 Health Check Path: /index.html

Step-08: Access Application¶

# Important Note
Wait for 2 to 3 minutes for the Load Balancer to completely create and ready for use else we will get HTTP 502 errors

# Access Application
http://<ADDRESS-FIELD-FROM-GET-INGRESS-OUTPUT>/app1/index.html
http://<ADDRESS-FIELD-FROM-GET-INGRESS-OUTPUT>/app2/index.html
http://<ADDRESS-FIELD-FROM-GET-INGRESS-OUTPUT>/

Step-09: Clean Up¶

# Delete Kubernetes Resources
kubectl delete -f kube-manifests

# Verify Load Balancer Deleted
Go to Network Services -> Load Balancing -> No Load balancers should be present

References¶

GKE Ingress Healthchecks