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Now I did already outline the problems.

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Problems start,

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when our containers are restarted.

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Now, here in this application,

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we got no obvious way of restarting a container

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because I got no error at point

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as I did have it in the past.

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But of course there could be circumstances

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where this container does restart.

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Because maybe it gets so much traffic

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that some process times out

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and therefore the container crashes and needs to be restart.

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There definitely are scenarios where this could happen.

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There are always scenarios where your applications crash.

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And when that container restarts,

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because currently we're not using any volumes here

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on this Kubernetes cluster,

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all the data would be lost.

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So the data which I'm getting here.

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And that's something we wanna solve with volumes.

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Now, if you search for Kubernetes volumes,

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you should find an article from the official docs.

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And of course there you can learn way more about it

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if you want to.

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But most importantly here,

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you find the different types

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of volumes which are supported.

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And that's what I meant before.

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Kubernetes, supports a broad variety

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of volume types and drivers.

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And the reason for that

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is that you don't just run Kubernetes

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on your local machine,

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even though we technically

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are doing this right now of course with minikube.

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But even that is a separate virtual machine

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on our local machine.

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So it is like a different machine in the end.

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But in reality,

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of course it will also use kubernetes

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to deploy your application

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to some cloud provider or some data center.

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And therefore you have a broad variety

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of

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ways of storing your data.

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Because it's not just your local hard drive

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as the case of just Docker volumes,

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but instead maybe you are using AWS

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and you wanna use their elastic block store service.

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Which is a service we haven't used

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up to this point in this course,

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but which is another storage service that you have

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or maybe you're using Microsoft Azure

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and therefore you wanna use one of these services

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or any other provider

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or type of volume here.

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And this list might look overwhelming.

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Of course in reality,

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you will not need all these types all the time.

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It depends on how you're hosting your application

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and the deeper you dive into Kubernetes of course,

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the more you will know about these different options.

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For

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this course section,

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we are going to focus on this CSI type.

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We are going to dive into the emptyDir type

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and we're going to have a look at the hostpath type.

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And actually we're going to start with emptyDir

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and have a look at the other types thereafter.

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The key thing is that

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all these types don't influence how volumes work

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inside of a container.

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There it's always just some path,

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which is then also stored outside of the container.

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So basically just like volumes work

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with just Docker as well.

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But the difference here just is that,

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how the data is stored outside of the container

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depends on which type or driver you use here.

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So with that,

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let's start with this emptyDir type here

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and let's learn how we can configure a volume

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with Kubernetes.