OpenShift Concepts TODEPLETE
Internal
Overview
OpenShift is supported anywhere RHEL is: bare metal, virtualized infrastructure (Red Hat Virtualization, vSphere, Hyper-V), OpenStack platform, public cloud providers (Amazon, Google, Azure). It runs on RHEL and Red Hat Atomic.
OpenShift Hosts
Master
A master is a RHEL or Red Hat Atomic host that orchestrates and schedules resources. It maintains the state of the OpenShift environment. Multiple masters can be present to insure HA.
The master provides the single API all tooling clients must interact with.
The access is protected via fine-grained role-based access control (RBAC).
Node
A node is a RHEL or Red Hat Atomic Host where applications run inside containers. Nodes are orchestrated by masters. The node daemon runs on node.
Container
All application instances run inside containers on the nodes. For more details, see Docker Containers.
The node Daemon
Pod
Volume
etcd
Scheduler
Docker Registry
OpenShift contains an integrated Docker registry. Users push images into registry and whenever a new image is stored in the registry, the registry notifies OpenShift about it and passes along image information such as the namespace, the name and the image metadata.