Deploy a sample app on openshift4

To set up a sample app on OpenShift and expose it using Ingress, you can follow these steps:

1. Deploy the Sample App: For this example, let's deploy a simple web application. You can use a Docker image from Docker Hub or build your own. Here's a simple YAML for deploying a sample web application:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: sample-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: sample-app
  template:
    metadata:
      labels:
        app: sample-app
    spec:
      containers:
      - name: sample-app
        image: your-sample-app-image:tag
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: sample-app
spec:
  selector:
    app: sample-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8080
---

Replace your-sample-app-image:tag with the Docker image you want to use.

Apply the YAML:

oc apply -f sample-app.yaml

1. Create an Ingress Resource: Define an Ingress resource to expose your application externally. Here's an example YAML for Ingress:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: sample-ingress
  annotations:
     cert-manager.io/cluster-issuer: letsencrypt
spec:
  ingressClassName: openshift-default
  rules:
  - host: example.com  # Replace with your desired hostname
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: sample-app
            port:
              number: 80

Replace example.com with your desired hostname. For this hostname, a TLS certificate will be created via cert-manager.

Apply the YAML:

oc apply -f sample-ingress.yaml

1. Access the Sample App: Once the Ingress resource is created and configured, you can access your sample app using the specified hostname (example.com in this example). Ensure that your DNS is configured to resolve the hostname to your OpenShift cluster's Ingress controller.

2. Verify Ingress Configuration: You can verify that the Ingress configuration is correct by checking the status of the Ingress resource:

oc get ingress sample-ingress

This should display details about your Ingress resource, including its status and any associated rules.

That's it! Your sample app should now be deployed and exposed using Ingress on OpenShift.