OpenShift

Intro

OpenShift is a PaaS (Platform aas) that lets you easily manage containers, using both Docker and Kubernetes.

Openshift-Origin is the open source upstream of OpenShift (like Fedora is to RHEL).

Redhat Atomic is the Enterprise release of Red Hat that is configured for containers. CentOS Atomic is the open source version. HOWEVER it seems that the base CentOS will work just fine. So let's skip this layer since it doesn't seem necessary.

So to get our open source PaaS, we install CentOS, then install Openshift-Origin on it. I think.

Quick Start (binary on existing VM/metal)

For a quick rampup, stand up a CentOS machine, and run a Red Hat Origin binary.

• Install prerequisites on your CentOS system:

yum install wget git net-tools bind-utils yum-utils iptables-services bridge-utils bash-completion kexec-tools sos psacct
yum update
systemctl reboot
yum install atomic
yum install docker
[root@C68 openshift-origin-server-v3.9.0-191fece-linux-64bit]# docker-storage-setup create first /etc/sysconfig/docker-storage-setup 
 Created storage configuration first
emacs /etc/docker/daemon.json
   add: { "insecure-registries": ["172.30.0.0/16"] }
# systemctl enable docker
# systemctl start docker
# systemctl is-active docker
iptables -F

• Binary instructions
• Binary releases - get client and server
• Untar the client, initialize it, and let it start the server:

cd ~/apps
untar (client).tar.gz && cd (client)
export PATH="$(pwd)":$PATH
# I might have had to run this a couple times?  reboot?  not positive yet...
oc client up --public-hostname=192.168.241.58

• Put this in a startup script, should work even after reboot:

iptables -F
oc cluster up --public-hostname=192.168.241.58

• (NO) I tried to untar the server directly and start it, but it was missing components:

cd ~/apps
untar (server).tar.gz && cd (server)
export PATH="$(pwd)":$PATH
sudo ./openshift start --create-certs=true

Quick Start (minishift on existing VirtualBox)

The next-easier way is to install a minishift cluster on VirtualBox. Minishift puts everything in one simplified package.

• Download the minishift command for your OS, put it in your path
• Ensure that VirutalBox is installed on that same OS
• Bootstrap it:

$ minishift start --vm-driver=virtualbox
-- Checking if VirtualBox is installed ... OK
-- Downloading OpenShift binary 'oc' version 'v3.7.1'
-- Starting local OpenShift cluster using 'virtualbox' hypervisor ...
-- Minishift VM will be configured with ...
   Memory:    2 GB
   vCPUs :    2
   Disk size: 20 GB
Downloading ISO 'https://github.com/minishift/minishift-b2d-iso/releases/download/v1.2.0/minishift-b2d.iso'
Pulling image openshift/origin:v3.7.1
OpenShift server started.
The server is accessible via web console at:
    https://192.168.99.100:8443
You are logged in as:
    User:     developer
    Password: <any value>
To login as administrator:
    oc login -u system:admin