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**Lars Wikman:** Yeah, yeah. \[laughs\] I'm absolutely talking about you there. |
**Gerhard Lazu:** I'm that guy, okay? So let's unpack this... I tried to answer this question a couple of times, and either people -- I must be answering it wrong, so let me try again. The reason why we chose Kubernetes is because it reached a certain level of maturity. That was one of the things. And Linode, our partn... |
We had to solve a couple of things, like for example DNS. DNS updates... Whenever the IP changes, or the load balancer changes, the IP has to be updated in the DNS. The certificate - we used to pay for those, and then Letsencrypt came along. So how do we get free certificates via Letsencrypt, and support that mindset? |
**Lars Wikman:** A cron job. |
**Gerhard Lazu:** A cron job. Excellent. Okay, great. A cron job. That is a valid answer. And then how do you push updates? Like, do you have your CI that deploys? In some cases you do. In some cases the CI is the thing that has the keys to the kingdom, and that's what we had. And it can do anything. Is that a good thi... |
How do you run backups? Another cron job, right? So before you know it, you have all these things that you need to have... Like, what gets for example docker-compose, or whatever you're using, in place? What installs Erlang? What determines which version of Erlang you have? What about the monitoring? Where do you run t... |
**Break:** \[39:37\] |
**Gerhard Lazu:** The way I approach this is "What is a system that can manage all these things in a way that doesn't have me worrying about versions as much?" Because we used Terraform, and then we had to do upgrades because it was running locally, we had plugin issues, we had to upgrade those... And the issues were p... |
We used Ansible, and - did we use Chef at some point? No. We didn't use Chef. We only used Ansible at some point, many years ago. By the way, there was like a progression, so every year we blogged about this, we talked about this... It didn't just come out of the blue, "I know, let's use Kubernetes." No. We'd been usin... |
I know that you mention large-scale... I don't think Changelog is very large-scale; it's a simple app, but it's still serving many of terabytes every month of traffic... And there's the CDN; when the CDN goes down there's a big problem, as we had a couple of days ago, and you have to know how to basically update it ver... |
So the answer is a bit more complicated. It's contextual, and it's not because I like Kubernetes, it's because it makes all these concerns easier than if we used anything else than we did before, by the way. It improves on that. |
**Lars Wikman:** Yeah. |
**Gerhard Lazu:** What do you think about that? |
**Lars Wikman:** Easier for you, I would say. For me, it's like - I barely know where I would start on making Kubernetes do this... And I did start looking at K3s specifically because I wanted the CD part. I wanted something to pick up my finished Docker containers and spin up the new version. That's essentially why I ... |
The thing is I don't see sort of keeping that load balancer up to date, or keeping certificates up to date as that complicated of an endeavor, with current baseline tools like Letsencrypt... So I wouldn't bring in layers to solve them. It could be a Bash script, it could be some fairly tightly spec-ed tools... For exam... |
\[44:13\] And with that, to some extent you might not even need NGINX at that point. I bet you would probably be able to serve Changelog with the previously mentioned SQLite performance of like 10k reads a second. You were talking about terabytes, and that's like the mp3 files, right? |
**Gerhard Lazu:** Mm-hm. |
**Lars Wikman:** So files serving is one of the places where I would typically reach for proprietary cloud stuff, like S3, or Linode Object Store, or one of those... Because it just solves a lot of the -- like, okay, I wanna still have some redundancy in this, I want to be able to scale it essentially arbitrarily. For ... |
Having NGINX in front of your app can be very nice, because it allows you to do things like "Oh, actually we're down for maintenance right now. I still wanna show something nice to the user." Or pointing to different instances that you're starting up, or whatever. But there's also the potential risk of your NGINX being... |
Also, one of the things with Kubernetes is all this -- like, any node can go away at any time; we're on very moving ground cloud infrastructure. We only use what we need... But you always need some, so usually you're at a base level, like "We have these instances up constantly." At that point, I'm like "But do you need... |
**Gerhard Lazu:** I think it would. And if you look at Changelog, at its core, that's exactly what we have. We have the application and we have the database. A single instance PostgreSQL. There's a great story how we used replicated PostgreSQL and how that was the cause of a couple of downtimes; I think we covered that... |
And CockroachDB - that's something which I definitely wanna try out. Distributed PostgreSQL with a PostgreSQL compatible wire format that's a very interesting one to try out, for sure. It's on my list. But I think what I'm hearing, going back to what you were saying, is that for you, getting started with Kubernetes see... |
\[48:01\] When it comes to NGINX, you don't install NGINX; you have Ingress NGINX, which is a component that exposes certain custom resource definitions (CRDs) and it's more like it implements Ingresses. Now, what is an Ingress? Do you care about it? Well, you do, because you need to know how to configure it; but beyon... |
**Lars Wikman:** But that's the whole thing... See, Phoenix is a fairly explicit framework. It has a few things that feel a bit magical, but it is quite explicit about everything it does. |
**Gerhard Lazu:** And Kubernetes isn't? |
**Lars Wikman:** Yeah, it's not the impression I'm getting... But what I see when you bring in something like Kubernetes - you're placing a lot of abstractions in place, and you're going to be working with those abstractions. Those abstractions are still doing all of the things under the hood, and you need to be aware ... |
This is a thing where I think Kubernetes ends up being a bit over -- I wouldn't say it's over-engineered. It's "Don't repeat yourself" taken quite far. And that's the correct move for some cases. For example, you'll see in enterprise software, things are often generalized, and the software is generally not that tight t... |
But let's say for example shipping updates to your app - the BEAM can hot code update your app while it's still running, without ever taking it down. That's a little bit trickier to use than a lot of other ways... It's not like bringing your container down and then bringing up another one, but it's definitely a capacit... |
\[51:56\] Or you can install something like PromEx and then you need to have Prometheus and Grafana stood up somewhere. Then you're starting to get a little bit more infrastructure, or you use the cloud offerings... And I think that's sort of always what it boils down to - at a certain point you need more visibility in... |
**Gerhard Lazu:** I think there is a lot of -- okay, so first of all there's simplicity in complexity, and the other way around. But in this case, in Kubernetes, it's complex, but it's also simple, if you look at it from a certain perspective. So things are fairly well defined; you know what to reach out for and how to... |
I think the separation of concerns gets a bit more clear... So anybody, just ship us a container image. It doesn't matter what language you have, it doesn't matter what VM you're running; ship us a container image, we'll take care of the rest. Now, I know it's too simplistic, but it works. |
Heroku, for example - shipping containers, they've made it popular. You just git push and things happen. And guess what - the way that Changelog has been developed hasn't changed. You git push and things happen behind the scenes. And because that contract has never been broken with the developers, everybody's happy. |
**Lars Wikman:** Yeah, Jerod would be pissed if he had to SSH into the server to set things up. |
**Gerhard Lazu:** There you go. |
**Lars Wikman:** That's no good. |
**Gerhard Lazu:** Yeah. Do you really care about which OS you're running? No, you don't. Do you wanna switch Erlang versions? Super-easy. Guess what - all you have to do is change the container. Hot code reloading? Yes, you can do it; it's hard, maybe you don't need to... And again, it doesn't matter whether you use Er... |
\[55:42\] I have used Chef, for many years. I gchef at one point (Gerhard Chef). There's even an org on GitHub... So I spent a fair time with that. Knife, when that was a thing - I don't think many people were using... Because Chef server was so difficult. I was there, I remember that period. Ansible - I loved it when ... |
**Lars Wikman:** Kubernetes is definitely a big step in some direction from Ansible. It's not just the next sort of iteration on scripting your servers; that's not what it is. It's something different. And you did ask me for a hot take that you could put as the title on this, and I think it would be fair to say Kuberne... |
**Gerhard Lazu:** Oh, okay... Wow. I think people are like "What is Electron?" That would be the first I'd ask. |
**Lars Wikman:** What?! |
**Gerhard Lazu:** What is Electron? Which electron do you mean? Do you mean the physical one, or the Electron JavaScript -- |
**Lars Wikman:** \[laughs\] Oh, you're like "Oh, physics...!" |
**Gerhard Lazu:** Exactly. |
**Lars Wikman:** Yeah, I mean in that it makes operations at the outset a lot simpler, but it also paves over everything that you could get right, and the details, I feel like. I think you have access to every little detail you would need in Kubernetes, but it doesn't particularly seem to encourage you getting into all... |
So whenever you add abstraction layers - and I think that's sort of my hesitance on adding more tools, especially tools that sit on top and sort of obscure what's going on... It's that I've come to rely on explicit things. Because if you can just read the code and see what it's gonna do - that's very powerful. I mean, ... |
**Gerhard Lazu:** Yeah. |
**Lars Wikman:** And if it doesn't have to be very complicated, and there's not a lot of complexity to manage, if you bring in a large abstraction layer, which is supposed to hide a lot of complexity and make managing very complex things possible, which I think is a fair thing to say about Kubernetes - it seems to make... |
**Gerhard Lazu:** Try decades... But yes, I agree. |
**Lars Wikman:** Yeah. I've spent much more time building the actual applications. I've spent a fair bit of time on servers, and operations, but not nearly the majority of my time, because I care much more about the building of the thing. And I consider the operations a part of what I do. I don't want to hand off a con... |
**Gerhard Lazu:** And on that thought, thank you, Lars, very much for joining me. This was a pleasure. I do realize that we have so much more to talk about. Dev and ops talking, finally... \[laughs\] I think for decades we've tried to do that, and it's finally happening. We have respect for each other, we know that eac... |
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