RHOCP 4 New Features (Red Hat Openshift Container Platform)

• CoreOS as the mandatory operating system for all nodes, offering an immutable infrastructure optimized for containers

• A brand new cluster installer which guides the process of installation and update

• A self-managing platform, able to automatically apply cluster updates and recoveries without disruption

• A redesigned application life-cycle management

• An Operator SDK to build, test, and package Operators

Kubernetes & Openshift Architecture & Terminology

Kubernetes Terminology

Node
Master Node
Worker Node/ Compute Node
Resource
Controller
Label
Namespace


Openshift Terminology

Infra Node
Console
Project

Kubernetes & Openshift Architecture

Kubernetes Resource Types 


Pods (po)

• Represent a collection of containers that share resources, such as IP address and persistent storage volumes. 
• It is the basic unit of work for kubernetes.

Services (svc)

•  Define a single IP/port combination that provides access to a pool of pods. 
•  By default, services connect clients to pods in a round-robin fashion.

Replication Controllers (rc)

• A kubernetes resources that defines how pods are replicated (horizontally scaled) into different nodes. 
• Replication controllers are a basic kubernetes service to provide high availability for pods and containers.

Persistent Volumes (pv)

•   Define storage areas to be used by Kubernetes pods.

Persistent Volume Claims (pvc)

• Represent a request for storage by a pod. 
• PVCs links a PV to a pod so it containers can make use of    it, usually by mounting the storage into the container's file system.

ConfigMaps (cm) & Secrets

• Contains a set of keys and values that can be used by other resources.
• ConfigMaps & Secerets are usually used to centralize configuration values used by several resources.
• Secreats differ from ConfigMaps in the secret's values are always encoded (not encrypted) and their access is restricted to fewer authorised users. 

Openshift Resource Types 

Deployment config (dc)

• Represents the set of containers included in a pod, and the deployment strategies to be used.
• A dc also provides a basic but extensible continuous delivery workflow. 

Build config (bc)

• Defines a process to be executed in the Openshift project.
• Used by the Openshift Source-to-image (S2I) feature to build a container image from application source code stored in a Git repository.
• A bc works together with a dc to provide a basic but extensible continuous integration and continuous delivery workflows. 

Routes 

• Represent a DNS host name recognised by the OpenShift router as an ingress point for applications and microservices.