24 Red Hat OpenShift and IBM Cloud Paks on IBM Power Systems: Volume 1
/SM590000Docker Client
A Docker client is primary interface with which the user can use Docker features, as shown 
in Figure 2-11. Docker client starts APIs in this process. Developers build applications by 
using Docker APIs. 
Figure 2-11   Docker orchestration 
2.4  Kubernetes: An open source container orchestration
This section describes Kubernetes open source container orchestration.
2.4.1  What is container orchestration?
Container orchestration is the process of organizing properly to achieve the wanted 
performance. Cloud-based applications are intended to be hosted on several commodity 
hardware on several hardware environments. These loosely coupled containerized objects 
must be organized and coordinated to meet functional requirement, such as starting and 
stopping an application, and grouping and coordinating applications in a cluster. Some of the 
most popular orchestration services are Apache Mesos, Google Kubernetes, and Docker 
Swarm.
A container platform that is lead by Docker is used to package applications that were divided 
into micro services. Such discrete services can be hosted on separate containers that are 
helpful during the continues integration and continues delivery process. Container 
orchestration is primarily focused on managing the lifecycle of containers for automated 
deployment, management of nodes, scalability and availability of services based on work 
load, and networking among distributed containers in large systems.
Container orchestration configuration is created in YAML or JSON files. Based on the 
declarative configuration, container tools perform one or more of the following tasks:
/SM590000Fetch required configuration image from repository by way of Docker Hub
/SM590000Establish networks across container
/SM590000Allocate storage and space