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I have just explained you.

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What is default bridge network and you know understand that containers may communicate between each

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other using own IP addresses assigned randomly by Dr. Holst and we can verify that using Too Busy Box

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containers.

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Next important concept is environment variable.

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Let me explain the thrust.

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What is an environment variable.

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And afterwards I'll explain you how you are able to set custom environment variable for specific container.

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Great.

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We are now still running to the box containers.

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Let me clear our time and no one of them.

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And here simply type command and view like so and you'll get list of let's say key.

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Well your piracy hero.

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He's all names of environment variables hostname CHL the L home DRM bath and BW deal.

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And that's up the fold the variables that are set to out of the box for every busy box container and

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again set of environment variables is different for different containers and we could easily verified

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it less in a nasal tap lounge and I was a container for example or born into container dock are all

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wrong.

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This item bundle and let's type in view here and you'll see a bunch of different environment variables

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that the way are set for these specific container.

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For example you'll see here variable called ALAS underscore coloreds or you'll see another hostname

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body but it is actually the same variable as it was set for those containers but hostname here is different

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of course from this hostname.

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Also you may see that such variables as BW due home are the same for this container and this container.

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But again those variables are set for each specific container individually.

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Also you are able to verify environment variables without logging into stage or by a shell by doing

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the following.

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Let me go out from this container terminal let's list the containers that are currently running.

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There are two busy box containers and you are able to use exact amount in order to execute Ian view

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command inside of the container.

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Let's do so.

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Docker exactly and here will be ideal container.

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For example this one a five and next type Ian view.

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Again here is command that will override default command and we will actually create additional process

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that will be executed inside of specific container with specific ideas.

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Let's press enter and you'll also see environment variables.

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But notice that there was this command you'll see less and environment variables then in this case because

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in this case we are looking at environment variables inside of DCH shell that actually added some additional

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environment variables when we have looked into stage show.

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That's the reason why here was a set of environment variables that is larger than here.

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Wonderful.

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But what does a sense actually of using indoors environment variables but often applications require

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some initial setting parameters like a password to use a name or some connection details or something

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else and you are able to set those values before start of the application.

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For example let's say that your application needs to connect to some external server and for that that

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it needs to use credentials username and password and it is not safe to store this user name and password

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inside of the application files.

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It is not safe at all because anyone else might easily read this user name and password and the use

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for its own purposes.

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This way you are able to initialize dos parameters username and password when application is started

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and you are able to use for that environment variables.

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Also you are able to override any default environment variables if you want.

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Again it's a pretty common concept to use environment variables in different applications and we will

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use those variables multiple times through our discourse.

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For now that's all for this Loescher.

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And let's proceed.

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And next as promised let's create my escrow container and see whether it will be started or not by default

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without any additional environment timetables.

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I'll see you next.

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Bye bye.