Kubernetes Kubernetes Contributor Summit - NA (San Diego) 2019, 27 Nov 2019

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From YouTube: Contributor Summit NA 2019: Level up your open source development skills on kubectl

Description

Are you ready to level-up your open source development skills? Do you want to make significant contributions to a vital area of Kubernetes? Do you have the commitment to become a SIG maintainer?

This workshop will be a deep immersion into kubectl development, with the goal of eventually creating knowledgeable SIG CLI maintainers. This fast-paced workshop will dig deep into the details of kubectl development, including common conventions and structures in the kubectl code base. After visiting these common areas, we will then pivot to addressing current, high-priority kubectl development projects. By the end of the workshop, each attendee will be well-positioned to contribute to one of these current kubectl initiatives.

As current maintainers of this code base, we commit to not just giving you the knowledge to address current kubectl issues, we will spend the necessary time after Kubecon to review PR's and mentor you to the next level. Our goal is to create a more thriving SIG CLI development community by mentoring the next generation of SIG CLI developers.

HOW TO PREPARE BEFORE THE WORKSHOP

In order to make the best use of our limited time, please prepare ahead of time.

You should have a laptop capable of building and running basic Kubernetes binaries, with the following software installed:
Go 1.13 (This is a change from the originally advertised Go 1.12)
git
make
bazel
kubernetes/kubernetes GitHub repo

With that, you should be able to compile and test the latest version of kubectl:

bazel build //cmd/kubectl
bazel test //staging/src/k8s.io/kubectl/...

For the best preparation, please check out the following codelab before the workshop:

https://github.com/seankubecon/kubernetes.git

Event link: https://events19.linuxfoundation.org/events/kubernetes-contributor-summit-north-america-2019/
Session link: https://sched.co/Vv6S

A

So we're, we're at about nine 37 now..

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So if you guys don't mind, I'll, uh, I'll, I'll start.

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And, uh, so what, what I've got running, right, uh,.

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Up here on the screen, right now is some of the preliminaries for some of the.

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Coding that we're going to do. I'm going to jump back to the beginning of this deck and give you guys,.

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Uh, the introduction before we start moving into,, there's gonna.

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Hopefully, we'll get to four different code: labs, today. um,. Let me.

B

This bag. okay.

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I'm sean sullivan., I'm a co-chair in the sig cli.

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I'm the other leadership for sig. eli, macho, [inaudible] and phillip are here.

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Um,, some of the other sig cli'rs that I'm familiar with, uh, richard is here.

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I know huawei is here, the api machinery. um,.

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And so what I wanna do is start off with what we're trying to do. Here.

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Uh, we're trying to kind of reinvigorate our sig cli community and we're gonna do.

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That by, uh, giving some of the, uh,.

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Common patterns and common knowledge of what,.

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Of kubectl development. and we're gonna present that. and,.

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And hopefully, uh,, if you're interested,.

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Uh, we're going to, this'll, be the first step. In, uh,.

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Creating some more maintainers for this sig. um,.

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So this is what I hope to accomplish today. Is these four areas.

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So we're going to talk about, we're going to, we're going to dive pretty deep into the code base for, for kube control.

A

Um, and the first part we're going to talk about the basic structure of most,.

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Uh, kube control, commands. there's,, you know,. What about 40 or so sub commands.

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And most of them all have the same structure.

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They use the cobra command and capsulation that structure, uh,.

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They have options and flags and the way that they're organized is all very.

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Similar. so once you've seen one command,.

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You can see that that structure is very similar to other commands.

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And we're going to actually today build an extra command and connected into kube.

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Control., it's just called the [inaudible] command. um,.

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And we're going to,, you know, after our first code, lab,.

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You'll be able to type kubectl fu minus h and get the help for it and kubectl.

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Foo options. and see the flags are the options for that extra command.

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Um, and then the second part is actually where we start really getting into some of.

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The deeper parts,, which is the api machinery. um,,.

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And also how to read resource files off the local file system.

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Um, and we're going to, at the end of that code, lab,.

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We'll add a resource helper and a resource builder, uh,.

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Which are, uh, uh, structures or encapsulations that kube control.

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You're going to see in many different kube control, commands. um,.

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And we're going to actually in the presentation, we're going to dig pretty deep into the rest api or what it looks like at the.

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Http level,, so that when you get to the higher levels of encapsulation,.

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You kind of know: what's going on underneath the covers. um,.

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And then the third part we're going to get to printing, um,.

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And we'll add a printer to our command. and then at the final part,.

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We're gonna add a unit test for our command., so I know this is pretty ambitious,.

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Uh, but let's see how far we can get, um, in this.

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Okay., so let's dig right in.. This is what a kook control command, sub command.

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Normally, it looks like it has an options struct and these options. Strucks are.

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There. they basically usually filled in with values from flags. um,.

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And then uh, kind of built up, maybe from, from certain values of flags.

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Uh, and you usually have a function called new command.

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Fu or whatever. new command, delete new command taint that takes two parameters of factory and some io.

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Streams and it returns a pointer to that particular cobra command.

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Now, in that function, you'll create a, a,.

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An instance of the, the options and then you'll create that command. uh,.

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I've left out just for space reasons. all of the usage,.

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Uh, variables that are part of this cobra command., there's going to be like a short description of the command, uh,.

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Some examples of the command, uh, and, and some,.

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A long help for the command.

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and then once we get to the most important part. Was, is run.

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When you run your cobra command., we almost always in every single one of these cobra sub commands have three.

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Parts that we call we and,.

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And they end up being methods on the options so that they'll have access to the.

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Values of the options when they're being called., and so we have a complete, which will fill in all of the options.

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Then we have validate, which is going to validate the options and then the,.

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The actual running, which is, you know, run foo or run, taint, run, delete,.

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so underneath that is where we end up connecting flags that uh,.

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So we define flags and we can connect them to this cobra command.

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And so for this one, I've only shown one flag and you could see that it's actually part of the cobra.

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Commander., this is this flag structure. and you could,.

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You could declare a particular variable and right here where it's says,.

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Uh,, it gives an address of a particular flag. That means that it's being copied into.

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That particular flag., whatever the value is., you have the name,.

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The default, and then you have some usage., so many of these different commands are actually going to look very,.

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Very similar. they're all going to have these, this particular structure.

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And, and we're going to get to build one today. okay., so this is just a couple,.

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I just want to spend a minute talking about the cobra command. yeah. macho.

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Yeah. yeah., so you want,, do you want the code?.

C

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That's a good point: actually. I'll get to that. right, right after this slide.

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So, uh,, I just wanted to mention a couple of things about the cobra command.

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It's,, it's an encapsulation for all of the kubectl ku control, sub commands,.

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Um, and it has a really strong support for post sig flags.

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It has a intelligent, uh,, help suggestions where, if you type in the wrong command, um,.

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It has automatic help generation., so you don't actually even have to do anything with, to have minus h,.

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Uh, show you help. it'll, show you the examples that you put in the command.

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It'll, it'll show you a long description, et cetera.

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Um, yeah,, that's uh,, and so this is,, that is the,.

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Obviously, the link for cobra command didn't want to spend too much time.

B

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Um,, why don't I, uh, follow along with what mochi mentioned.

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So, where are all of these commands so.

B

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So if you look at this structure at the bottom of this buffer,.

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You'll see that are all of the code or almost all of kube control,.

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Um, is in two different places. we're moving kube control to what we call staging.

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Um,, there's still a little bit of the code left under package. Kube control,.

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But if you look here, you'll see that, uh,, you know,.

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This is basically the kubernetes route and then under staging source,.

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K8S.Io um,, actually, let's look at the,.

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At this one, uh, sorry.

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At the very top package, command and you'll see that there's actually quite a few.

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Of the commands there., so let me.

B

See if I can get this to respond.

B

B

Okay. there we go. okay.

A

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okay., so this shows all of the different kube control sub commands and where they're.

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Located under staging source, case,.

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Start out kubectl package command, and here's all the different commands.

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And this is the command that we're going to add fu,.

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But you can see that there is delete, apply,, annotate, expose,.

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Uh, customize label. so,.

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So this is where most of our commands are located.

B

Okay., let me, uh,.

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Transition back to these are the two parameters to almost all of these commands.

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You'll get a factory and you'll get a set of io streams.

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And the factory is mostly to, uh,.

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To build structures, for, um,, for,.

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For talking to the api, server, or maybe even for talking to the local file system, to read, jamo files off the.

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File system,, which is what's called the resource builder.

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So, do you have a question, lars did that?.

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Okay., so we're gonna dig into actually some code right now and what we're going to do.

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Uh, so,, so here's some of the,, the preliminaries. uh,.

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As I was mentioning before, where the code is located,, uh, is,.

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Uh,, most of it in three locations. uh, staging source,.

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Case dye, kubectl, and then also there's some left in packaged kubectl.

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We're going to move that into staging as well. um, and we,.

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We actually reuse a lot of the code. That's under a staging cli runtime.

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And actually I, I, uh, wrote that wrong. it's cli dash runtime.

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And so a lot of the,, a lot of the code that is reused is and reused into. Plugins has been refactored.

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Into cli runtime., so the resource builder,, the resource, helper,.

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Uh, I keep mentioning these, we'll, we'll,, we'll dig into them. Shortly. um,.

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Some of the,, the common print, uh, print flags and print options and printers, those are all under cli runtime.

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So I'm gonna,, I'm gonna, actually walk around now and hopefully we'll be able to do bazell.

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Builds. and if not, I've got some of the kube control., uh,.

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Some of the make commands down here..

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I think basil might be more successful for us. If you have it,.

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Um, installed and you're, if you're used to that, um,.

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After you've built kube control,, the binary is located with basil.

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This is the location for the, uh, for the binary.

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And here's a couple of the, the make commands..

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This is how you're going to make kube control. so,.

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So before we download this food, command,.

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We're going to do a get, get clone or uh, we're going to add a repo and then,.

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Um, actually update and,, and, and actually download this.

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Uh,, but before we do that,, let's make sure that we all are on the same page with building kube control.

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So does anybody want any help?.

B

So richard, you already,.

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Okay, good., so is there anyone who's familiar with building??

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I don't have much experience. Building with, with a windows.

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Can you type them?.

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Because I think we have at least one person who's building with windows.

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Yeah., so I think there was like, with basles.

B

Yeah., so how we deal with,.

B

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Yeah,, the one 12. yeah,- I just did that myself just actually right before I came.

B

C

People get come there, then it is actually working because.

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This unofficial.

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So you want it this way.

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Slightly different location.

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Is actually where I've added.

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So I'm actually gonna move on to describing some of the api machinery stuff just.

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So that we can, you know, for those of you who have already been able to compile the food command, uh,.

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We're gonna move on to the second part,, which is kind of talking to the communicating with the api server and also being.

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Able to read and decode jamo files off the file system.

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So this, this is going to be a,.

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There's going to be a lot of complexity, here.

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I'm going to try to make this.

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As possible without,, but still being able to get stuff, done.

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So there's api machinery is a deep pool.

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There's a lot here and I am necessarily going to not,.

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Uh, to not be able to get into all of the, uh, the deep,.

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Uh,, some of the niches and, and it's gonna. It's going to be missing some of the subtleties and the nuance.

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And I'm going to not even talk about particular parts altogether,.

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But uh,, hopefully this is enough so that you could get an understanding of how to use.

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The two structures that cube control uses most,, which is the resource helper and the resource builder.

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Okay,, so here's a layering, uh,.

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One layering of, uh,.

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Of how we think about talking to the api server.

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So at its very lowest level, there's a rest protocol over the http and I'm going to show some examples of.

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What that looks, like., it's, and above that we have encapsulations that the first layer of encapsulation is.

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Going to be a rest client., it's going to be a client that understands this rest protocol over http.

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And then, above that, there's going to be these structures that we normally use in.

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Kube control,, which is the resource helper and the resource builder.

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Now, mochi mentioned earlier,, you know,, I'm talking about api machinery.

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Actually,, it's slightly more nuanced than that, in that some of these structures are able.

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To read and decode a resource yammel off the file system.

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So not necessarily just the, uh, the api server.

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So, let's actually look at the lowest level first. you know,.

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What is,? What is this rest? Protocol? well,? If you do a kubectl,.

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Uh, get po, if you've got some pods,.

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You say: kubectl get po minus v equals eight,.

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Nine or 10, you're actually going to see what's happening at this lowest level. At this rest.

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Level., and what you can see is that we have different methods like http methods,,.

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Like get post patch,.

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And then you have a particular url that maps to resources on at the api server.

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So this here is actually asking for all the pods.. This is a kubectl,.

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Get po or get pods., and this is what it maps do.

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And there's particular request: headers and there's a user agent.

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And if you do this,, these particular commands,.

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You can actually see at this level, right?.

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This is the lowest level of talking to the api server.

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So this is the response., so we get some response headers and the important part is uh,.

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For this part, where it's a, it's a table, but it can also be a pod, right? it's,.

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It's actually a jason blob in the response. Body.

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And so what we're going to talk about, and I think, what a lot of these classes in the ap apm machinery have built to do.

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Is actually the main object is to how do we get this blob into a strongly typed.

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Go object, go struct for for instance, a pod.

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This is a table, but for,.

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For that particular type,, it's going to have, there's going to be a kind of version,, a group version of kind.

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And I'm going to talk about that in a second.

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So, so as I mentioned, a lot of this machinery is this particular transformation of this response body.

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Into this golang struct.

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Or the other way around.

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if we have a golang struct of a pod and we're creating it and the a that's going.

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To be a post at there at the rest, level,.

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Then it's going to have to encode this golang struct, as this jason.

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Blob in the body.

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Okay. so,, so, as I mentioned, before, there's a lot,, a significant amount of complexity, here. and again,.

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This is simplifying things dramatically,, but I want to actually go over a few of the classes that are going to peak out.

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From underneath the,, these lower levels that you're gonna have to understand in order to,.

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To uh, productively use kube control.

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So the first is this group version kind now: group version kind, is,.

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It's just a,. I've put some examples: there, like apps v1 deployment or core v; one pod.

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It ends up being,. If you look at the, the uh,, the code,.

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It ends up being just three strings.. You know, a group,.

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A version v1 or b, one alpha,, one b, one beta, and then the kind,.

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Which is, you know, pod, deployment, component, status.

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And then you ha, you'll, see what's a gvr.

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So I bring this up only because to keep you from getting too confused.

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It turns out that they're pretty much the same, that it's also three strings and it also basically describes the same concept.

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There might be slight nuances.. I think that the uh,.

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That the, the gvr was created in order to be able to,.

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To have different end points for diff, for the same kind or maybe the other way. Around.

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like one kind, can have multiple end points,. I forget.

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But for all intents and purposes,, a gvr is, is equal to a gvk.

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So now we're going to talk about arrest, mapping.

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you're, going to see rest mappings in the code.

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Arrest mapping is just a gvr and or gvk, and it's namespace scope.

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It could be cluster scoped. in other words,. It doesn't have a namespace.

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It's scoped to the entire cluster, or it can be scoped to a particular namespace.

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That's all that scope means.. So when I first read this, to be honest,.

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I was slightly confused for a little while, until you know,.

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Finally, click that this rest mapping is a gvk and some information on whether or.

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Not it's in a namespace., that's it., so,.

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So then, we're going to move on to a scheme.

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So we're going to need to use a scheme in order to be able to decode in kubectl.

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And a scheme is actually just telling you which gvk says we understand,.

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It's all,, it's literally just a list of a bunch of group versions.

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So you had a question.

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Uh, so yeah, correct., so different versions of kube control.

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Like right now we're building it at, uh, you know,, one 17 is coming out,.

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They're going to have different understandings of what the versions of r are,.

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The most current versions of these, uh,.

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Of these kinds of these group version kinds., so we've recently just changed like extensions v, one beta one used to be a what?.

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Deploy the, the, the most recent version of a deployment or,.

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Yeah,, it was a deployment. and is that right?.

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And we changed it to apps v one, right, that,. That happened just recently.

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So how can we translate? so give me a second here: that's actually slightly deeper than that.

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I wanted to go right now,, but that's a good question. well,, I'm going to,.

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Let me finish out here with the glossary and then, uh, I'll hopefully,.

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Hopefully I'll at least touch on that particular question. so,.

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So from the scheme, which tells you, you know,.

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All the group versions that this particular kube control, understands,.

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We have this concept of a codec and you'll also see serializer. Now literally.

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Codec is a sera., a serializer is a codec.

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It's type deft as a codec. and a codec is just the encoders and decoders that understand. For,.

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For all the g vks how to encode and decode from these jason bytes into these.

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Golan strucks.

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And, and as you mentioned, they're different., each one,.

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Each version of, of a kube control is going to have a different understanding of what the,.

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What we call the, the state of the art or you know,, what the current versions of the gvk is, are.

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and those are updated. Periodically. uh, you know,.

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They go from alpha api's to beta api apis to ga.

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so, so above, above them rest protocol,,.

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We have this a rest, client, that same client, go.

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And here's, basically all of the methods that it understands.

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And you could tell that most of these correspond to a http method.

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So there's, there's a gap, there's a patch, there's a put delete.

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And then there was a couple of extras., so just so we don't get too confused,.

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This is a narrowing of that rest, client interface, that we use.

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Under,- and this is I,- I've shown up top where this, uh,.

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Where this interface exists., so your general client go, has an interface and.

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In kube control, we've narrowed it to g to be just those particular rest. Methods.

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So you're going to see the rest client in a lot of different places that that's.

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What this is.! It knows how to spit out that low level,.

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The, the http method and to generate the url in order to talk to the api server to,.

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To do the crud operations on the api server.

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Okay. so at the highest, at the highest level,, the level that we're,.

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We're dealing with in coop, there's two structures that we deal with the most.

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There's a resource builder and a resource helper.

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And these are also under the cli runtime,.

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A staging cli, runtime hierarchy.

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So the builder is what we use to retrieve a resource,.

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Whether it's on the file system.- and this was a good point- that mochi made,.

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Whether it's on the file system or on the api server, and it understands how to.

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Decode it into these golang strucks.

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The the builder does,, the helper, is more, uh,.

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It's,, it's actually,, it has more functionality and that it actually can do, uh,.

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You can create and patch on the api server.

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It's not just retrieving,, but it's basically a wrapper around the rest. Client.

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It makes the rest client easier to use.

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Okay,, so now what we're going to do for those of you who've been able to connect your.

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Food command in, we're going to actually add a resource builder and a resource helper to,.

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Uh, we're going to read in. once you, once you've added this builder,.

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You should be able to read in a file, a yammel file,.

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And it should be decoded into a struct.

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Like if you're reading in a pod, it should,, it should actually, uh,.

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Decode it into a pod..

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It's only going to give it to you as a runtime object,.

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Which is the highest,?

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It's a very thin interface over every single type of object. um,.

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Let me see and we're going to actually add a resource helper.

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Okay,, let me go to some of the code. Here.

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Okay. so for in the interest of time, I've actually,.

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If you check out the next branch,.

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If you were able to finally get that code, um,.

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If you could con dash c s, dash works shop, dash two,.

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You'll see that this is how we've added a builder and lower down a helper.

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Um, so, uh,, as I mentioned in the interest of time,.

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I'm just going to move through this., I'm not gonna uh,, I'm going to show,.

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Show you how we've already done this cause? I don't think we're going to have.

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Time., so this is what the resource builder looks: like.

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Now, I mentioned before, when we're talking about the glossary,, the scheme,.

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So, where we're building or we're using this builder,.

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This resource builder, with the scheme,.

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There's a kube control has its own scheme..

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We know which gbk is that it understands and you,.

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You could tell your,, I think your question earlier was: what's the priority of the particular?.

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So, so there's actually, uh,.

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Methods that will automatically prioritize these g groups and versions for you.

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So for instance,, the apps v, one is higher priority. Now than extensions b. One beta one was before.

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Was recently. so that it'll find the apps, one v? One deployment before it finds the extensions.

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V1 beta one deployment. did that,. Did that answer your question?.

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It's you, you're actually going to find it. if you look,, if you did a,.

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If you looked under the kubectls scheme,, the prioritized versions,.

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All groups, it's going to have that prioritization for you.

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So once we call do with this bill,, so the most,.

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The other more important thing in this particular example is the file name per.

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Annum., so I've added an option for the file name, options and I'll show that up top.

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And when we call do it actually will return a result that we're going to iterate.

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Through by visiting. so,.

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So you're going to see this quite often in a lot of the kube control code.

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So, let's look,, so this is what happens with the results from that builder.

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So you're going to iterate,. This is a very,, very common pattern. You're going to iterate through and you're going to, uh,.

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You're going to receive or visit on, infos.

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So this info has an object in it,, which is the actual object that got decoded. and it's a,.

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As I mentioned before,, it's a runtime object.

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And so what I've done? Is,.

C

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I've got,, I got the resource mapping,, which is very close to a rest. Mapping.

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And from that, and using the factory,, I was able to create a client arrest, client.

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And with the rest, client, I was able to create the helper.

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And from that I was able to,. So if you run this code,.

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It actually will read the,.

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The a yammel file into its object.

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and it'll create it on the api server.

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So, so you'll see that I added some options so that we could read in this file. Name.

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So this resource dot file, name options is a standard way to read a file,.

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A directory or what's not going to get into it.

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A customized build of the resources into this file, name, options,,.

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So, so now I'm gonna open it up to questions.

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So we've got,, I think we got about 20 minutes left.

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So does anybody, anybody want to try to,.

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And that builder. so there's,.

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There's two more sections after this, and we only have 20 minutes., so I might just present on how we do printing and,.

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And actually get into a little bit of unit testing. so,.

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Uh, kind of give up a little bit on the, the coding part.. I apologize for,.

A

I think it was way too optimistic on what we're able to get to get done. Today.

A

Uh, but hopefully, uh, by presenting this information,.

A

You know, somewhere else,, you know, later on we'd, be able to actually fill in the food sub command,.

A

The sub command that we were downloading and actually fill in the unit test.

A

So, let's just go on to printing.

A

Okay. so this,, this is a common pattern, uh,.

A

Throughout kube control,, which is from flags.

A

You're going to build important, structures.

A

and so there's actually a standard set of print flags for kube, control,.

A

Uh, under generic cli, cli runtime. again,.

A

I keep going back to that and from those flags we're going to build the printer,.

A

The,, the ability to print a resource. um,.

A

And then that resource printer, we're going to add only that,.

A

That interface only has one method,, which is print obs., so,.

A

So this is how kind of we've layered how printing works.

A

So this is extremely simplified just so that we could,.

A

We could get a high level understanding of how printing works, within, uh,.

A

Uh, within kook control. and so I'll, I'll actually show how that works.

A

So we've actually added a, um,.

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Some more, some print flags to our options. Struct.

A

And these are standard print flags.. So why do we do that?.

A

So within kube control, you could do a kube control,.

A

Get pod minus, oh name, minus oyamo, minus,.

A

Oh, jason. there's many different standard ways that you can print.

A

And this automatically,, this structure automatically gives you all of that.

A

All of the standard ways to print within kube control are given to you with the.

A

Standard cli, options. print flags.

A

In fact,, why don't we,, let's see if I could get into the,.

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So here's the print flags., you can see: there's jason and jamo print flags, uh,.

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The name print flags., there's a template, printer. uh,.

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There's, you know, different outputs., so here this is,.

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This is what the print flags actually looks like..

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This is what it gives you off. The bat.

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So, so once you've declared that in your options,.

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Then you're going to actually create an instance of that.

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Um,- and this particular created is the operation that happens.

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And so that can get printed under certain circumstances., so like,.

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Because in this food command, I've created,, you know,.

A

I'm sending one of these resources to the api server to store it.

A

I want it to say it got created., so this is the option when you pass in those print flags,.

B

Let's see what looks like a,.

A

And it's the default output I want is the minus own name, meaning it's going to.

A

Print pod slash the ne..

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You know if it's a pod, that I'm printing pod slash the name of the pod.

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So if you ever see that when you,, if you do a kube control, get pod,.

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The name of the pod minus own name,, it's just going to print the name of the pod and the type and the kind actually.

A

From the gvk., that's one of the,, one of the ways to print under kube control.

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So,, so I said that that's going to be my default printing.

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And then up here, I'm actually gonna from those flags.

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You could see, I create a printer,, it's just two printer.

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And then, after I've created this objects by sending it to the api server,.

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I just call it print obs,, sending it to [inaudible] to one of the io streams as the standard out,.

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Usually standard out stream. and I printed the object.

A

And so let's see if we,.

B

B

So here's my food,, if I do.

A

So because my default printer was the name printer,.

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It prints it out in the,, uh, the,.

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The name format, kind, name.,.

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But if you wanted to do minus oem, all right,, this is,, you know,.

A

Very common way of doing this., if I can get this to, actually.

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It's going to print it out. oh, whoops.. I don't know why that happened.

B

B

B

A

This leg is quite a household,.

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So it didn't say anything because it didn't create it, because it's already.

A

There. so let me delete it.

A

All right,, sorry about the lag. uh,, but once I'm going to rerun this minus oem or a command, it'll,.

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It'll print it out in the yammer format. actually.

A

Actually, I have to actually run the fu one more time or no,. Actually, I don't.

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Yeah, so there we go., so it printed it out in the yammer format.

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That was a little bit long to do. That. so,.

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So that's printing. um,, and so I think,.

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Let's see how much time we have left. we've got 10 minutes..

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So now what I'm going to do is actually show you a few examples of how to write.

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Unit tests for kube control, commands. and the reason,.

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Uh, that I think that this is important to see examples is cause. It's actually quite.

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Awkward, the way that we.

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Mark out communicating with the api server., we actually go all the way down to the http layer and we mock out using a test.

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Factory, what the responses are from, you know,.

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Given a particular http, a get or post or whatever the rest,.

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Uh, um, request: is we mock out what the return is.

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And so I'm going to show us some examples of what our, uh,.

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Unit testing looks like just so. You could get used to this kind of relatively.

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Awkward way of marking, out, uh, stuff., so we,.

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So we know that for each one of these commands we have two parameters.

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We have a factory and we have these io streams.

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And so, in order to unit test, our command,.

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We kind of have to fake out those two things.

A

and I'm going to show you some examples of how we fake that out. and again,.

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With the test factory,.

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Many times what you're going to see as that, we dig all the way down to the http.

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Layer to mock out what the communication looks like to the api server,.

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Which is,, as I mentioned, before, it's quite, to be honest,.

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It's a little bit awkward., but let me show you some examples so that when,.

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When you do see some unit tests for kube control,.

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This is what it's gonna look like.

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Okay., so this is a test where we're creating a test. Factory,.

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Um, and we have to actually add our own codec.

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And so this is the kind of awkward part, which is we're,.

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We're creating a fake rest client in our factory,.

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Which is hard coding, for, you know, this particular http request.

A

we hard code or mock out an http response.

A

And you could see, we fill in the body.

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So for instance, we would fill in the body of the http response with a,.

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Using this codec and one of the w these items that we're able,.

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We were able to,, where is the items?.

A

Oh, it's the rc,, which is the test data,, which is a particular, there's,.

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It gives you a bunch of different uh,.

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Resources to test that,, you know, hard code, like a pod or a deployment or a service., and you could grab one of those items and actually throw it directly into the.

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Http response of the body., so this is,.

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This is kind of the super awkward park.

A

And [inaudible]., so the rest of it is actually somewhat clean in that you create your command and.

A

Then you spit you,, you put into it this test factory that has the mocked out interaction with the.

A

Api server, as well as some test streams.

A

And then you just set up the flags you want and you call execute.

A

And then you're going to look at one of the buffers that's associated with one.

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Of the streams and you're going to see, well, did it print out what I thought it was going to print out?

A

or usually what you're looking for is the a buffer from one of the streams to.

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See what, what you think happened actually happened.

A

Okay., so I think that we're coming up to about five minutes before the end of this.

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Session. um, I'm going to actually, uh,.

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Plug our sig cli session that we're having on thursday,.

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Right?, so this is,, so as part of what we described, uh,.

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What we wanted to do initially for, for this particular, uh,.

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Presentation I talked about,, you know, digging into the,, you know,.

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The dirty details of kube control; development., but also we,.

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We eventually want to get to what is our vision, right?.

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What are we going to use this information for?, right? and,, and this is where,.

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You know, we're,. This is this invitation to all of you to join the sig cli and to join in our.

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Vision of what we're going to build. um, and we're not going to get to obviously that vision, here.

A

We just don't have enough time.. We didn't even have enough time to cover these four parts of a coupon shoulder.

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Development., but in that sig cli session,.

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We hope to inspire you to talk about,.

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Um, uh, what we hope to accomplish with kube control and with, you know,.

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Again, we'd love to hear your input,, but we're, we're going to try to get us all under the same page so that we're all marching.

A

In the same direction on how we see kube control going forward and what,.

A

What we want to work on and what we want you guys to join us to work on with,.

A

With us. okay. I'm going to actually,, I think that this next session, is,.

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Is got five more minutes. okay.

A

Um, [inaudible] well,, actually I didn't,, didn't, have a whole lot more than, than that. actually.

A

We'll look at, if you want to,, we'll look at one more example of what these unit tests look like just so that,.

A

Again, you get used to this kind of kube control way, of, of doing,.

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Um, a unit testing., and so you don't, you can,.

A

You can make sense of this., let's look at, um,.

A

The taint toast.

A

Okay. so here's another example: of, of the unit testing and how we're hard coding, the, uh,.

A

The http response.

A

We're, we're creating the test factory, we're creating the test, io streams.

A

And then we're actually sending those into the command and uh,.

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And then executing it and checking out the response.

A

Okay. yeah, you've got a question.

A

So,, so the mocking for the control plan is actually done all the way at the low.

A

Level, http level., that's just the way,.

A

I mean we're actually mocking out what the response from the api server looks.

A

Like at the http level., so that's what that fake, client, was,.

A

That fake rest client, that it was saying, you know,.

A

This is the object, that's being returned.. These are the headers, uh, in,.

A

In response to this particular http, request.

A

A

yes. so,, so the integration test for kube control, is,.

A

Uh,, it's make a test dash cmd and it's under,.

A

Let me see if I can find it.

A

So,, so I might not be able to find it in the time that we've got, but I'll,.

A

I'll come over and talk to you about it., but there that, that actually is,.

A

There is a very significant, uh, integration test. That's only available under make.

A

Okay., so I'm gonna,, I'm gonna, stop it. There and, um,.

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But I'm going to be just right outside if you guys want to talk to me. um,.

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And I'd really love to talk to,, you know, any of you guys, who, uh,,.

A

Are interested in,, in, uh,, you know, more kubectl? Development.,.

A

Please just meet me outside and, and let's,: let's have a few, uh, let's,.

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Let's talk for a few minutes. uh, love to hear your experiences and what you're looking for.

A