Deploy an Application

Overview

This guide describes how you can deploy a demo application to the cluster.

Requirements

• A working ingress controller and cert-manager as described in Create an Ingress Controller.
• A DNS record pointing to the external IP of the ingress controller.

Deploy an application

For this How-To we are going the deploy the nginx hello image to our cluster. There for create a Deployment:

cat <<'EOF' | kubectl apply -f -
kind: Deployment
apiVersion: apps/v1
metadata:
  name: nginx-hello
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx-hello
  template:
    metadata:
      labels:
        app: nginx-hello
    spec:
      containers:
      - name: nginx-hello
        image: nginxdemos/hello:0.2
        livenessProbe:
          httpGet:
            path: /
            port: 80
          timeoutSeconds: 1
        readinessProbe:
          httpGet:
            path: /
            port: 80
          timeoutSeconds: 1
EOF

Make the application accessible from the outside

To make the application accessible from the outside, we first have to expose it with a Service:

cat <<'EOF' | kubectl apply -f -
kind: Service
apiVersion: v1
metadata:
  name: nginx-hello
spec:
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  selector:
    app: nginx-hello
EOF

And then create an Ingress resource which registers it at our ingress controller and fetches a TLS certificate for it:

cat <<'EOF' | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx-hello
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
spec:
  tls:
  - hosts:
    - nginx-hello.your-domain.com
    secretName: nginx-hello-tls-secret
  rules:
  - host: nginx-hello.your-domain.com
    http:
      paths:
      - path: /
        pathType: ImplementationSpecific
        backend:
          service:
            name: nginx-hello
            port:
              number: 80
EOF