By now, you should have a first taste of an OpenStack cloud.
Let's lay the foundation, whatever is a cloud, and what is OpenStack?
This module starts with a formal definition of the term cloud
computing, and positions OpenStack in this frame of reference.
We then have a quick look at the history of the OpenStack project
before we introduce its various components.
To conclude, we will go on a tour of the resources available to you to
learn more about the technology.
The National Institute of Standards and Technologies in the USA, NIST,
published a definition of the term cloud computing.
According to this definition, cloud computing has the following essential characteristics.
Self service of computing capabilities over the network.
There is no need to fill in forms and get approval for setting up a
server, for example. Resources are allocated from a pool that is
shared with other consumers. A consumer doesn't know where exactly
the resources are located, although most clouds allow a certain level of control.
Elasticity, if more resources are needed, allocate more, if less is
required, release resources. The effect is almost instantaneous.
Getting more resources and releasing them can even be done
automatically by a cloud application. Finally, the service is metered.
Your resource usage is recorded, and you may be billed for it.
Try to keep these four essential characteristics in your mind.
We will occasionally refer back to them during this course.
NIST also defines three service models. The highest level is SaaS,
os SaaS, Software as a Service. The services provided there are
applications like email or office. Famous examples are Gmail and
Outlook.com, or Google Docs and Microsoft's online version of Office.
PaaS, Platform as a Service, is targeted to application developers.
The cloud gives its consumers a development and deployment platform.
Think of programming languages and development environments including
easy-to-deploy web servers and databases.
IaaS, or Infrastructure as a Service, provides data center resources
like servers, volumes, or networks to its consumers.
This is where OpenStack traditionally belongs, although it has added
quite a few services over time that can be counted as PaaS or even SaaS.
Red Hat's EX210 exam remains at the IaaS level, and so does this course.
As I said, we will refer back to this formal definition throughout the
course, but now let's focus on OpenStack.
After a quick look at its short history, you will study its structure.
OpenStack started from two projects, a private compute cloud developed
and used by NASA, and an object storage system owned by Rackspace,
an American-hosting company. They combined their two projects,
open sourced the code, called the result OpenStack, and invited others
to participate in its development. In July 2010, the first OpenStack
design summit was held in Austin, Texas, and in autumn that year,
the first OpenStack release, named Austin after the summit location, was published.
Soon two releases were made per year in April and October.
In 2017, this was changed to February and August.
Release names are related to the location of their summit and follow the alphabet.
The Red Hat EX210 exam is based on OpenStack Newton from October 2016.
Development has obviously not stopped with Newton.
At the time this course is being written, development for the 18th
release of OpenStack, baptized Rocky, is in full swing.
In the few years since 2010, OpenStack has seen tremendous growth.
Almost 200 companies and about 2500 individuals are now participating
in the development of this project.