Deploying to OpenShift

Chapter 13. Services, Networking, and Routing

When you deploy an application, whether it is a web application or a database, you need it to be accessible so other application components, or users, can access it. You want to be able to control, though, who or what can access it.

In most cases, when you deploy an application in OpenShift, it will be accessible only to other application components running in the same project. In order to make a web application visible so that users outside the OpenShift cluster can access it, you need to create a route. The creation of a route gives your web application a public URL by which users can access it.

In this chapter you will learn about the relationship between containers and pods, how your application can access other applications running in the same or a different project, and how you can expose your application to external users.

Containers and Pods

Your application, when deployed, is run within a container. The container isolates your application from other applications. From within the container, your application can see only processes that are a part of the same deployed application. It cannot see the processes of applications running in other containers.

When containers are run directly on a host, although applications are isolated from each other, all the containers will normally share the same IP address and port namespace.

This means that if you want to run multiple instances of the same web application, all wanting to use ...