WEBVTT

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Hello and welcome to this section
on multi-container pods.

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The idea of decoupling
a large monolithic application

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into sub-components
known as microservices

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enables us to develop and deploy a set of
independent, small, and reusable code.

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This architecture can then help us
scale up, down,

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as well as modify
each service as required

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as opposed to modifying
the entire application.

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However, at times, you may need
two services to work together,

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such as a web server 
and a logging service.

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You need one agent instance
per web server instance paired together.

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You don't want to merge and bloat
the code of the two services,

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as each of them target
different functionalities,

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and you'd still like them
to be developed and deployed separately.

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You only need the two functionality
to work together.

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You need one agent per web server instance
paired together

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that can scale up and down together.

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That is why you have multi-container pods
that share the same life cycle,

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which means they are created together
and destroyed together.

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They share the same network space,

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which means they can refer to each other
as local host,

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and they have access
to the same storage volumes.

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This way,
you do not have to establish

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volume sharing or services
between the pods

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to enable communication
between them.

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To create a multi-container pod,

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add the new container information
to the pod definition file.

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Remember, the container section

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under the spec section
in a pod definition file

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is an array,
and the reason it is an array

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is to allow multiple containers
in a single pod.

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In this case, we add a new container
named log-agent to our existing pod.

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Well, that's it for this lecture.

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Head over to
the coding exercises section

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and practice configuring
multi-container pods.

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See you in the next lecture.