Kubernetes is a popular container orchestrator. 2 2
Let's go back to the original definition from previous 3 3
sections on what orchestration is, at least 4 4
when it refers to containers. 5 5
All an orchestrator is, is it's taking your 6 6
containers that you ask it to run, and it's 7 7
taking a series of servers, or nodes, 8 8
and deciding how to run those container workloads 9 9
across those nodes. 10 10
Kubernetes was an orchestrator, one of many, 11 11
that was released in 2015 by Google. 12 12
It's now maintained by an open source community, 13 13
around the world, that Google is a part of. 14 14
If you wonder what Kubernetes is doing, or 15 15
how it's related to Docker, Kubernetes essentially 16 16
is a set of APIs that run 17 17
on apps in containers to manage a set of servers 18 18
and then execute your containers on Docker, 19 19
by default. It can run other container runtimes 20 20
that aren't Docker, like containerd. 21 21
By default, right now, it runs on top of Docker. 22 22
So, it's not getting rid of your container runtime. 23 23
It's just a series of containers on top of that 24 24
that manage the multi-node system that it's 25 25
controlling. 26 26
Then, it gives you a set of those APIs 27 27
and command line tools to deploy 28 28
and maintain the same server infrastructure 29 29
that you would have similar to Swarm. 30 30
Before in this course, you've been using the Docker command 31 31
a lot. 32 32
In Kubernetes, one of the main tools you will be using is 33 33
kube control, or kubectl. 34 34
If you've heard other people refer to that tool as 35 35
something else, like kube control, or kube cuddle, 36 36
or koob control, these are all different names. 37 37
But now that we have a standard naming 38 38
from the official repo, it is called 39 39
kube control. 40 40
When it comes to Kubernetes and how do you get it, 41 41
there's tons and tons of options out there. 42 42
The most common ways you're going to use Kubernetes 43 43
is one, from a cloud vendor, 44 44
that is going to provide you Kubernetes as a service 45 45
to run your containers. Much like their other cloud 46 46
services, they will provide you the Kubernetes 47 47
endpoints, the API, that you can use the tools 48 48
locally, or GUIs that maybe they have built into 49 49
their cloud interface, to deploy and maintain 50 50
your Kubernetes controlled containers. 51 51
Then, there are other vendors, most of them infrastructure 52 52
vendors, that package up their own Kubernetes as 53 53
well. We're going to call these distributions 54 54
of Kubernetes, similar to the concept of Linux 55 55
distributions. In the Linux world, there's the same 56 56
Linux kernel running on all these different distributions. 57 57
Those kernels are sometimes built a little bit different, 58 58
or different versions, but they're fundamentally the same. 59 59
Then, the distributions, whether it's Ubuntu, or CentOS, 60 60
or Amazon Linux. 61 61
All these different distributions package up their own set 62 62
of tools that a lot of us prefer one or the other 63 63
because of. That's the same way with Kubernetes now. 64 64
Whether it's cloud or on-prem 65 65
data center distributions of Kubernetes, 66 66
you're going to pick one based on your requirements, based 67 67
on existing vendor contracts, or your preference on 68 68
operating system or vendors. 69 69
There's lots of reasons to do that. 70 70
But, all of those are providing a what we call 71 71
upstream version of the pure, open 72 72
source Kubernetes. Then they layer on top of it all 73 73
their own extra stuff to your benefit.