-: Hello and welcome.
In this section, I wanna start to tackle two
very important questions that we're going to be answering
throughout this entire course.
The two important questions are, what is Docker?
And secondly, why do we use Docker?
We're gonna first tackle why we use Docker
by going through a quick little demo right now.
Now I'm gonna show you a little flow diagram
and this is a flow of probably a process
you've gone through at least once in your life before.
It's a flow
of installing software on your personal computer
and I bet at least once for you, this is what has happened.
Maybe you have downloaded some installer,
you run that installer, and then inevitably
at some point in time
you end up getting an error message during installation.
So what do you do?
Well, you probably troubleshoot the issue
by looking on Google.
You try to find a solution, you eventually solve that issue.
You then rerun the installer only to find,
hey, ta-da,
you have some other error appearing, and then you have to go
through this entire troubleshooting process again.
So this is at its core what Docker is trying to fix.
Docker wants to make it really easy
and really straightforward for you to install
and run software on any given computer.
Not just your computer, not just your personal laptop,
your personal desktop, but on web servers as well
or any cloud based computing platform.
I wanna give you a very quick demonstration
of this flow right here in action,
and then show you how quickly I can solve
installing a problem whereas me installing
a piece of software by making use of Docker.
So I'm gonna very quickly go through the flow
of installing a piece of software called Reddis.
Reddis is an in-memory data store.
We're going to be using it quite a bit
throughout this course, but for right now
I just wanna give you a quick demo
of how it can be a little bit challenging to get installed
on your own computer.
So I'm just gonna go
through the installation steps here very quickly.
So this is the Reddis homepage.
This is the official download page.
In theory, I could use the documentation here
to install Reddis on my local machine.
I'm gonna go down to the installation section
and it very proudly says,
"Oh yeah just run these four commands right here,
and boom that's pretty much it.
You can then run Reddis."
So I'm gonna grab the first command right here.
I'm gonna copy it
and then I'm going to run it inside my terminal.
So I'll paste, there's the same exact command.
I'm gonna run it, and sure enough, yep
I get an error message.
Now in this case, the error message
is a little bit predictable.
It's complaining about a program that is just
not installed on my local machine.
Now, I could definitely go and troubleshoot this
install that program, and then try installing Reddis again,
but that's the whole point.
You kinda get into this endless cycle
of trying to do all this troubleshooting
as you are installing and running software.
So let me now show you how easy it is to run Reddis,
if you are making use of Docker instead.
I'm gonna go back over to my command line
and I'm gonna run one single command.
I'll say Docker run, dash it, Reddis, like so.
I'll hit enter, and then
after a very brief pause, almost instantaneously
I have an instance of Reddis up and running on my computer.
And that's pretty much it.
That is Docker in a nutshell,
that is how easy it is to run software
when you're making use of Docker.
So to answer the question very directly
of why we use Docker, well,
we make use of it because it makes life really easy
for installing and running software without having to go
through a whole bunch of setup
or installation of dependencies.
Now, we're gonna learn many more reasons
throughout this course of why we use Docker
but I wanted to give you a very quick demo
and show you how easy it can be to get up and running
with some new piece of software when you are using Docker.
Let's take a quick pause right here.
We're gonna come back to the next section
and start trying to answer the question of what Docker is.
So I'll see you in just a minute.