OpenShift

OpenShift is a computer software product from Red Hat for container-based software deployment and management. It is a supported distribution of Kubernetes using Docker containers and DevOps tools for accelerated application development.

In the world of Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS), OpenShift is Red Hat's PaaS.

Different flavours of OpenShift:

OpenShift Origin 

Open source application container platform

OpenShift Online 

Public Application Development hosting service

OpenShift Dedicated 

Managed private cluster on AWS/Google Clouds

OpenShift Enterprise 

On-premise private PaaS

This article will mainly discuss OpenShift Origin.

OpenShift Origin is based on top of Docker containers and the Kubernetes cluster manager, with added developer and operational-centric tools that enable rapid application development, deployment, and lifecycle management.

• OpenShift Tools:
  • Source Code Management (SCM) -> git
  • Pipelines (CI/CD)
  • Container Registry (OCR), for Docker images
  • Software Defined Networking (SDN)
  • API
  • etcd (stores the state of the various OpenShift components)
  • Governance (managing teams and users to provide access to applications and services)

• Three ways to interact with OpenShift:
  • Web console (default port: 8443)
  • CLI (OpenShift Client, oc)
  • REST API

Minishift

Minishift is a tool that helps you run OpenShift locally by launching a single-node OpenShift cluster inside a virtual machine. With Minishift you can try out OpenShift or develop with it, day-to-day, on your local machine.

• Install minishift

• Start up a single node OpenShift "cluster":

$ minishift start --vm-driver virtualbox

• Install and configure oc:

$ minishift oc-env
$ export PATH="/home/champ/.minishift/cache/oc/v3.9.0/linux:$PATH"
$ eval $(minishift oc-env)

• Add ability to login as Admin:

$ minishift addon apply admin-user
$ oc login -u admin  # password = admin

• Get token for API (valid for 24 hours):

$ TOKEN=$(oc whoami -t)  # E.g., ZndWHOAc7SfJspq3-CwBsb1Wxn7R3zqt9gI2RsABt6M

• Get a list of OpenShift users:

$ curl -kH "Authorization: Bearer ${TOKEN}" https://192.168.99.101:8443/oapi/v1/users

{
  "kind": "UserList",
  "apiVersion": "v1",
  "metadata": {
    "selfLink": "/oapi/v1/users",
    "resourceVersion": "9069"
  },
  "items": [
    {
      "metadata": {
        "name": "admin",
        "selfLink": "/oapi/v1/users/admin",
        "uid": "270ab9d2-6f44-11e8-bb58-527977685b9f",
        "resourceVersion": "8551",
        "creationTimestamp": "2018-06-13T19:58:33Z"
      },
      "fullName": "admin",
      "identities": [
        "anypassword:admin"
      ],
      "groups": null
    },
    {
      "metadata": {
        "name": "developer",
        "selfLink": "/oapi/v1/users/developer",
        "uid": "f3ed520b-6f37-11e8-bb58-527977685b9f",
        "resourceVersion": "1083",
        "creationTimestamp": "2018-06-13T18:31:14Z"
      },
      "identities": [
        "anypassword:developer"
      ],
      "groups": null
    }
  ]
}

OpenShift Client

• REST API:

$ TOKEN=$(oc whoami -t)
$ curl https://localhost:8443/oapi/v1/users \
    -H "Authorization: Bearer ${TOKEN}"

External links

• Official website