🌐 Application Deployment on the Kubernetes Cluster

This guide simply shows how to Deploy your applications on the Kubernetes Cluster in Nuvion by SaveinCloud.

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🚀 1. Application Deployment

We will simply and functionally publish an Apache Pod on the internet through port 80 using Ingress with Traefik in Kubernetes. The structure will be:

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• 1. Apache Pod + Service
• 2. Ingress using Traefik
• 3. External Access Test

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• Create the Apache Pod with the file apache-pod.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: apache
spec:
  replicas: 3
  selector:
    matchLabels:
      app: apache
  template:
    metadata:
      labels:
        app: apache
    spec:
      terminationGracePeriodSeconds: 0
      tolerations:
      - effect: NoExecute
        key: node.kubernetes.io/unreachable
        operator: Exists
        tolerationSeconds: 2
      - effect: NoExecute
        key: node.kubernetes.io/not-ready
        operator: Exists
        tolerationSeconds: 2
      containers:
      - image: httpd
        imagePullPolicy: IfNotPresent
        name: apache
        ports:
        - containerPort: 80
          protocol: TCP

-Apply:

kubectl apply -f apache-pod.yaml

-Check:

kubectl get pods
kubectl get pods -o wide 

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• Create the Service to expose the Pod with the file apache-service.yaml
• The Ingress does not point directly to the Pod, it points to the Service.

apiVersion: v1
kind: Service
metadata:
  name: apache-service
spec:
  selector:
    app: apache
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: ClusterIP

-Apply:

kubectl apply -f apache-service.yaml

-Check:

kubectl get svc

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• Create Ingress using Traefik with the file apache-ingress.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: apache-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: treinamento.seudominio.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: apache-service
            port:
              number: 80

-Apply:

kubectl apply -f apache-ingress.yaml

-Check:

kubectl get ingress

-Example output:

• Check if Traefik is running:

kubectl get pods -A | grep traefik

kubectl get svc -A | grep traefik

• In the Nuvion Panel, we can navigate to the Load Balancers screen and note that a Traefik Load Balancer was created, for TCP/80 and TCP/443 ports with Active status and 3 members each. We can also validate that it has a private IP and in the next step we will create and associate a Floating IP (Public IP) so that with this public IP we can create an A record in our DNS Zone and point to our subdomain. With the subdomain responding, users will already be able to access the web application.

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• In the Nuvion Panel, navigate to the Floating IPs screen and add a new Floating IP for our Traefik Load Balancer by clicking the + Add Floating IP button:

• Select the public network

• We will associate this new IP to our Load Balancer

• In IP address select the Private network

• Click the ADD button to create

• Configure DNS - Create an A record pointing to the Cluster IP:

apache.seudominio.com -> IP_DO_NODE_TRAEFIK

• Or Test via /etc/hosts:

IP_PUBLICO treinamento.seudominio.com

• Test Access:

curl http://treinamento.seudominio.com

• Or open in the browser (The default Apache It Works! page should appear)

http://treinamento.seudominio.com

• Screenshot with the Final Architecture of this simple project:

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🚀 1. Troubleshooting in Kubernetes

These are the most used commands for troubleshooting in a cluster. They help investigate pod, node, network, storage, events, and log issues.

• Check the overall Cluster status:

kubectl cluster-info
kubectl cluster-info dump
kubectl get componentstatuses
kubectl get nodes
kubectl get namespaces

• Full Summary:

kubectl get all -A

• Advanced debug with temporary container:

kubectl debug pod/pod-name -it --image=busybox

• Most used command for quick Troubleshooting:

kubectl describe pod pod-name && kubectl logs pod-name

• Restart Pods / Deployments

kubectl rollout restart deployment deployment-name

• Check rollout status:

kubectl rollout status deployment deployment-name 

• Pod Troubleshooting

• View full pod details:

kubectl describe pod pod-name 

• View container logs:

kubectl logs pod-name

• Real-time logs:

kubectl logs -f pod-name 

• Previous container logs (when restarting):

kubectl logs pod-name --previous

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🧠 Questions?

Contact our SaveinCloud technical support team!