Deploying to OpenShift

Chapter 5. Deploying Applications from Images

Now that you have created a project, you can move on to deploying an application.

In this chapter you will start out by deploying an application from a pre-existing container image hosted on an external image registry.

You would use this method if you created the image for the application outside the OpenShift cluster, or the image was being made available by a third party.

Once you have deployed the application, you will make it public so users can access it. You will then reconfigure the running application using environment variables, and scale up the number of instances of the application in order to handle a growing amount of traffic. You will also be shown how you can delete an application.

Deploying Your First Image

OpenShift supports deployment of container images hosted on any image registry that can be accessed from the OpenShift cluster. The first image you will deploy is stored on Docker Hub and is named openshiftkatacoda/blog-django-py. The application in the image implements a simple blog site.

Tip

The full name of the image used is docker.io/openshiftkatacoda/blog-django-py. When you leave off the hostname for the image registry, OpenShift will default to first looking for the image on any global image registries that a cluster admin has specified in the cluster configuration. It is typical to have the Docker Hub image registry included in that list. A company image registry or the Red Hat Container Registry might also ...