Realizing container orchestration
We've now seen which challenges container orchestration framework tackle. This section will show you the core concepts of Kubernetes, a solution originally developed by Google to run their workloads. At the time of writing this book Kubernetes has a enormous momentum and is also the basis for other orchestration solutions such as OpenShift by RedHat. I chose this solution because of its popularity but also because I believe that it does the job of orchestration very well. However, the important point is less about comprehending the chosen technology rather than the motivations and concepts behind it.
Kubernetes runs and manages Linux containers in a cluster of nodes. The Kubernetes master node orchestrates the worker nodes which do the actual work, that is, to run the containers. The software engineers control the cluster using the API provided by the master node, via a web-based GUI or command-line tool.
The running cluster consists of so-called resources...