How to Deploy Applications in OpenShift

OpenShift, a powerful Kubernetes platform by Red Hat, is designed for rapidly developing, deploying, and managing containerized applications. This tutorial guides you through deploying applications on OpenShift, ensuring your services run smoothly and efficiently.

Prerequisites

• Familiarity with OpenShift (Official site) basic concepts.
• A working OpenShift environment (local or cloud-based).
• Access to the OpenShift CLI (oc command).
• A sample application ready for deployment (such as a Docker image).

Step-by-Step Guide to Deploying Apps

1. Set Up Your OpenShift Project

Begin by creating a new project in OpenShift:

oc new-project myproject

This command initializes a new project named myproject, providing a namespace for your application.

2. Deploy Your Application

Next, deploy your application using the following command:

oc new-app  --name=myapp

Replace <docker-image> with your application’s Docker image. This command creates a new deployment in OpenShift.

If you’re new to deploying containers, read our guide on Managing Kubernetes with Rancher for additional context.

3. Expose Your Application

To make your application accessible externally, expose it with:

oc expose svc/myapp

This creates a route that maps an external URL to your service, allowing external access.

4. Configure Auto-scaling

Ensure your application can handle load variations with:

oc autoscale dc/myapp --min 1 --max 10 --cpu-percent=80

This command sets up autoscaling, automatically adjusting pods based on CPU usage.

Troubleshooting Deployment Issues

If you encounter deployment problems, use the following commands to diagnose issues:

• oc get pods – Lists current pods and their states.
• oc logs <pod-name> – Displays the logs of a specific pod to troubleshoot errors.
• oc describe pod <pod-name> – Provides detailed information about a pod, useful for identifying configuration errors.

Summary Checklist

• Create an OpenShift project.
• Deploy the application using Docker images.
• Expose the application to the outside world.
• Set up and configure autoscaling.
• Troubleshoot deployment issues using OpenShift diagnostic tools.

By completing these steps, you’ll successfully deploy applications within OpenShift, leveraging this robust platform’s full potential.