OpenShift Introduction

OpenShift is the container service the Mass Open Cloud has deployed.

If you haven’t heard of containers it is useful to read about them: (https://en.wikipedia.org/wiki/Operating-system-level_virtualization)

Specifically, OpenShift uses docker containers(https://en.wikipedia.org/wiki/Docker_(software)).

Docker containers have minimal storage requirements and are immutable. Basically, making a change to one container will not change all of the containers of that type. If you should change a container and redeploy the same container, your changes would not be kept. Thus being immutable implies that any information which contains state needs to be in persistent storage.

Storage for a container can either be describe as ephemeral or persistent. Although they are both attached to the container, ephemeral storage will be released when the container is stopped. However, persistent storage will remain after the container is release.

OpenShift uses kubernetes to orchestrate the deployment and management of the docker containers.

Additionally, OpenShift augments Kubernetes with many features useful for enterprise. From a developer’s perspective, the source to image (s2i) build process is very convenient to start developing applications quickly.