I have just explained you.
What is default bridge network and you know understand that containers may communicate between each
other using own IP addresses assigned randomly by Dr. Holst and we can verify that using Too Busy Box
containers.
Next important concept is environment variable.
Let me explain the thrust.
What is an environment variable.
And afterwards I'll explain you how you are able to set custom environment variable for specific container.
Great.
We are now still running to the box containers.
Let me clear our time and no one of them.
And here simply type command and view like so and you'll get list of let's say key.
Well your piracy hero.
He's all names of environment variables hostname CHL the L home DRM bath and BW deal.
And that's up the fold the variables that are set to out of the box for every busy box container and
again set of environment variables is different for different containers and we could easily verified
it less in a nasal tap lounge and I was a container for example or born into container dock are all
wrong.
This item bundle and let's type in view here and you'll see a bunch of different environment variables
that the way are set for these specific container.
For example you'll see here variable called ALAS underscore coloreds or you'll see another hostname
body but it is actually the same variable as it was set for those containers but hostname here is different
of course from this hostname.
Also you may see that such variables as BW due home are the same for this container and this container.
But again those variables are set for each specific container individually.
Also you are able to verify environment variables without logging into stage or by a shell by doing
the following.
Let me go out from this container terminal let's list the containers that are currently running.
There are two busy box containers and you are able to use exact amount in order to execute Ian view
command inside of the container.
Let's do so.
Docker exactly and here will be ideal container.
For example this one a five and next type Ian view.
Again here is command that will override default command and we will actually create additional process
that will be executed inside of specific container with specific ideas.
Let's press enter and you'll also see environment variables.
But notice that there was this command you'll see less and environment variables then in this case because
in this case we are looking at environment variables inside of DCH shell that actually added some additional
environment variables when we have looked into stage show.
That's the reason why here was a set of environment variables that is larger than here.
Wonderful.
But what does a sense actually of using indoors environment variables but often applications require
some initial setting parameters like a password to use a name or some connection details or something
else and you are able to set those values before start of the application.
For example let's say that your application needs to connect to some external server and for that that
it needs to use credentials username and password and it is not safe to store this user name and password
inside of the application files.
It is not safe at all because anyone else might easily read this user name and password and the use
for its own purposes.
This way you are able to initialize dos parameters username and password when application is started
and you are able to use for that environment variables.
Also you are able to override any default environment variables if you want.
Again it's a pretty common concept to use environment variables in different applications and we will
use those variables multiple times through our discourse.
For now that's all for this Loescher.
And let's proceed.
And next as promised let's create my escrow container and see whether it will be started or not by default
without any additional environment timetables.
I'll see you next.
Bye bye.