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[Intro Music]

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We have just successfully created

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the new custom bridge network. It is

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called 'custom', and this driver is

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bridge. And here you'll see Subnet

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that will be used for assignment of

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the IP addresses to containers in

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this custom network. Now let's stop

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those two containers that we

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have created in default bridge

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network; and afterwards, let's

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create again two new containers in

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custom network, but we will not use

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now '--name' option; and we

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will not use '-h', hostname

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option. We will let Docker create

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custom names on its own. Great. Let

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me exit from this sh shell, clear

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terminal here, and let me exit from

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this sh shell, clear terminal as

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well, and let me actually using

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'docker container prune' remove

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existing containers. Yes. And

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afterwards, let's clear terminal,

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and start first container

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here using 'docker run -it

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busybox' command, like so without

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name option and without h option.

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But we will add additional option.

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Basically let me first run here

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'docker run --help'

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command and show you option that we

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will use now, it is '--network'

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option, here it is. And

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with this option, we are able to

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connect container to specific

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network. And again by default

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without this option, containers are

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attached to default bridge network.

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Great. Let's use this option.

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'docker run -it --network',

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and after this parameter,

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let's specify the name of the

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custom network we want to connect

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this container to. And in our case

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name is simply 'custom'. Let's type

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this name like so. And afterwards,

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let's type the name of the image we

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want to use for this container. And

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name will be same as before,

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'busybox'. 'busybox'. Let's press

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Enter. And let's verify which IP

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address was assigned to this

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'busybox' container. 'hostname -i';

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and here you see address

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from network range that was

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assigned to our custom bridge

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network, this range. And if I'll

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enter here, 'docker network inspect

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custom', you should see now

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container that was attached to this

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custom network. Here are the

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details about this first

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container. Here is its random

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name, "heuristic_lumiere'; here is

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MacAddress; and here's IP address,

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same as we see here in this output.

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Great. Let's now in the same way,

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create one more 'busybox' container.

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Let's go to this step, 'docker run

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-it --network',

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again 'custom' here, and the name of

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the container, image sorry, 'busybox',

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Enter. And let's verify IP

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address of this container, 'hostname

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-i', 172.18.0.3. Let's go back to

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this last step, and verify whether

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this container was attached to this

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'custom' network. And yes, now I see

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here in this output two containers

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with different IP addresses of

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course. Here is first container.

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Here it is. And here's the second

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container. Here you see IDs of

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containers, here ID of the first

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container, and here is ID of the

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second container. And here are

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their IP addresses, this one and

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this one. Wonderful. Let's now

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verify connectivity between those

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two 'busybox' containers; and first

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let's as usually ping using IP

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address 172.18.0.3. And yes, I get the

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response from second container. And

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now let's try to ping by hostname.

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Let's check hostname of this

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container, 'hostname' like so. Here

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is hostname. Let's copy it, go

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here, and use this hostname with

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ping command. And now I get

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response. It means that using

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custom network we are able to

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communicate between containers

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using their hostnames. It is a

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very important outcome. And that's

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how picture differs from default

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bridge network, where we were not

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able to communicate using hostnames.

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Great. Let's now verify whether we

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will be able to communicate between

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containers using their names. Recap

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the names were assigned randomly by

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Docker. Let's clear terminal, and

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actually you're able to find out

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which names were assigned to

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containers here in this section.

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Name is here for container with

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this IP address. And basically its

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container running in my case in

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this first step; and name for second

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container is here. Here it is. And

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now using this name let me try to

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access second container using same

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ping command from first container,

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this one. 'ping', and let me paste

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the name of the second container;

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not hostname, name; Enter; and I see

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'bad address'. Great. That's outcome

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we have at the moment. We are able

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to communicate between containers

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using their hostnames. But

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hostnames are actually random. And

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they are assigned randomly. And

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they are actually based on ID of

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specific container. Here, you see

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that, 'hostname', you see first

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few characters of ID of specific

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container. Here is actually full

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ID, here it is. And of course,

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it's not convenient to use IDs for

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communication between containers.

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We also have just verified that we

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are not able to communicate between

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containers using randomly assigned

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names, this name or this name. Here

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you see response, 'bad address'. But

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now let's try to launch same two

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'busybox' containers using custom

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names instead of randomly generated,

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but let's try that of course after

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the small pause, I'll see you in a bit. Bye-Bye.

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[no audio]