The state of the art for cluster management will probably something completely different by then. Better to build a good product now and if you really want to turn it into a startup, productionize it then.
> Maybe I see all the news about Kubernetes and think it would be cool to be more familiar with it.
If learning Kubernetes _is_ your side project, then perfect go do that. Otherwise its just a distraction, taking more time away from actually building your side project and putting it into building infrastructure around your side project.
If what you really wanted to build is infrastructure, then great, you're doing swell, but if you were really trying to build some other fun side app, Kubernetes is just a time/money sink in almost all cases IMO.
I generally dislike this way of thinking. Infrastructure is a core component of whatever it is you're building, not an afterthought. Maybe you can defer things until a little bit later, but if you can build with infrastructure in mind you'll be saving yourself so many headaches down the road.
You don't need to build with the entire future of your project's infrastructure in mind, but deploying your project shouldn't be "ok now what?" when you're ready, like it was a big surprise.
That's true in some sense -- but you can get surprisingly far using a PaaS like Heroku to abstract that infrastructure away.
I'm a big fan of Kubernetes, and use it in production at my company, but I would not recommend using k8s in a prototype/early-stage startup unless you're already very familiar with the tool. The complexity overhead of k8s is non-trivial, and switching from Heroku to something like k8s doesn't involve undoing much work, since setting up Heroku is trivial.
There is something to be said about having the infrastructure in mind though. That's why I'm inclined to use something like Elixir/Phoenix for web-based projects. Some (not all) of the ideas that K8S brings to the table are already built into the Erlang/OTP platform.
As for Heroku, there was a recent announcement that I think shifts things quite a bit: https://blog.heroku.com/buildpacks-go-cloud-native ... having standardized container images that runs buildpacks.
The ecosystem and tooling is not quite there yet, but I can see this as significantly reducing the investment to put into Dockerizing your app for K8S.
At that point, for the hobbyist, it might be:
Prototype -> Heroku -> K8S with an Operator that can run the buildpack
K8S is really a toolset for building your own PAAS. If there were a self-driving PAAS (using Operators) targeting small hobbyists that will run cloud native buildpacks, then the barriers of entry for a hobbyist using K8S is much lower.
I don't agree with this; that's one of the things you can do with it for sure, but multi-tenant isolation is actually one of k8s' weak points -- for example by default you can access services in any namespace, and you need something quite specialized like Calico and/or Istio to actually isolate your workloads. Plus you're still running workloads in containers on the same node, so inter-workload protection is nowhere near as good as if you're using VMs.
I see the big value add of k8s as making infrastructure programmable in a clear declarative way, instead of the imperative scripting that Chef/Puppet use. This makes it much easier to do true devops, where the developers have more control over the infrastructure layer, and also helps to commoditize the infrastructure layer to make the ops team's job easier, if you ever have a need to run your own on-prem large-scale cluster.
This sounds like exactly what I'm advocating. I wasn't saying that you need to build specifically with Kubernetes in mind, but some people aren't even thinking about what it means to deploy to Heroku. Maybe you do some small amount of reading and research to know "switching from heroku to kubernetes is a viable migration path.' What I strongly dislike is this mentality:
> taking more time away from actually building your side project
None of what I've mentioned is time taken away or lost. Time spent doesn't just pause when you are ready to deploy or productionize. SWEs need to think more holistically about their software's lifecycle.
Great, so use something appropriate for a small side project which in 99.99% of cases will not be k8.
Unless the small side project is learning cluster management. In which case go nuts.
K8's operating cost ($) might be manageable for a small project, but that doesn't mean the upfront learning and implementation costs (hrs) don't exist.
Your time isn't infinite.
I think one of the underlying assumptions that this article missed about the original is that building a side project often isn't about what the end result will be. It's about the skills you pick up along the way.
If you have a killer product idea and you need to get it to market as quickly as possible then by all means, take the fastest route. But maybe you're working on something that's just a copy of an existing app so you can get the flavor of a new language or framework.
If that's the kind of project that someone's working on then whether or not k8 is applicable to the scale of the finished product is irrelevant. What matters is 1) do they see a benefit in increasing their knowledge of k8, and 2) can they do so without significantly ramping up the cost of the project.
The original article answers question 2, and provides a few arguments as to why the answer to 1 might be yes in the current job market.
I don't really want to get into a debate over the relative merits of k8s or any other way of doing things in production, but I do want to throw out a general observation: The technologies we use always solve problems that we have. This cuts two ways: If you have a problem, you'll find a technology to solve it. On the other hand, if you have a technology, then soon enough you'll find a problem that it can solve -- even if you have to create the problem for yourself first.
Until then I think my efforts are best spent making a simple monolith.
Has it not only changed twice in the prior two decades between first VMs and now containers? Don't think this is something you have to worry about long term.
I'd describe cluster management as four things - provisioning + configuration, resource management (CPU+RAM+Disk), scheduling (when & where to put things based on availability/resources), and deployment (running things). At least, these are the things I'm concerned about when managing a product that requires a cluster (besides monitoring).
Early cluster management tools were often just doing provisioning and configuration (CFEngine). We see Puppet, Chef, and eventually Ansible further refine the solution as we enter the "Bronze Era" where standing up new servers take a fraction of the time. Now we didn't even bother to name each server by hand when we were going through the installation process after booting up the OS - servers had become cattle, and they were tagged appropriately.
Around the same time (2003-2006) we see virtual machines begin to catch on, culminating in the 2006 debut of Amazon Elastic Compute Cloud (EC2) and the birth of modern cloud computing. We now had a general purpose mechanism (VMs) to spin up isolated compute units that could be provisioned, configured, and managed using tools like CFEngine & Puppet. IT departments begin spending less on the SANs that dominated the early aughts and shift budgets to AWS or VMWare ESXi.
Then in 2006 we see Hadoop spin off from Nutch, and the MapReduce paradigm popularized by Google leads to an optimization of the resource and scheduling problems thanks to YARN and Mesos and related tools. Non-trivial programs and workloads can now be scheduled across a cluster with vastly improved confidence. Distributed programs are now in reach of a much larger audience.
Suddenly new Hadoop clusters are springing up everywhere and the "Silver Era" begins. Tools enabling greater efficiency hit the scene like RPC serialization frameworks (Thrift, Protobuf), improved on-disk storage (O/RCFile, Parquet), distributed queues (RabbitMQ, SQS), clustered databases (Cassandra, HBase), and event streaming and processing (Storm, Kafka).
Coordination becomes more complicated and essential, so we get ZooKeeper and etcd and consul. Managing passwords and other secure data leads to tools like Vault. Logstash and Graylog make log management less of a nightmare. Solr leads to Elasticsearch leads Kibana and we now have logging and visualization for both server and application monitoring.
Developers also begin to take advantage of VMs and it's not long before tools like Vagrant help bridge the gap between development, staging, and production. Our profession takes a collective sigh of relief as getting our distributed programs started on a new developers machine went from three days of trial-and-error to minutes thanks to well-maintained Vagrantfiles.
Still, deployment is a big pain point. A single cluster could be home to Hadoop (which benefits from YARN) and thirty other things being run by teams across the organization. One day you discover that your mission critical web app is sharing resources with your BI team after your CEO calls you in a panic to tell you the website is down. Turns out a DBA transferred a 20TB backup across the same switch shared with your customer-facing website because somebody forgot to isolate a VLAN to prevent backups from interfering with other traffic.
This doesn't even take into the consideration the abominations we call deployment scripts that developers and DevOps wrangle together to get our programs deployed.
Then Docker and containers become a thing. Developers are now able to setup incredibly complex distributed programs with little more than text files. No more coordinating with DevOps to make sure your servers have the latest version of libpng, or spending months fighting to get Java upgraded to the latest version. I shout in glee as I delete Chef from my machine because progress. Then the beer goggles dissipate and the love affair ends and we realize things are shitty in a different way.
Docker Swarm and Kubernetes emerge, and that brings us to today which I'll call the "Golden Era". We now have incredible tooling that deals with provisioning and configuration, resource management, scheduling, and deployment. But like any new era there are rough spots, but I'm positive incredible new tech will popup.
Throughout all of this, virtual machines and containers were the fundamental building blocks that enabled improved clustering and cluster management. They're inextricably tied together. But all-in-all, things have changed VERY little (couhg LXC cough) in 20 years compared to the rest of the landscape. We're solid for another 10 years before anything like this is going to happen again.
Well, you gotta deploy with something. Why not k8s?
Obviously if you're developing locally, k8s would not help in the least.
For your average developer who just wants to get something running on a port, Kubernetes introduces two barriers: containerization and Kubernetes itself. These are non-trivial things to learn, especially if you don't have an ops background, and both of them add substantial debugging overhead. And again for that developer, they provide very, very small gains.
I think the calculus changes if that developer starts to run multiple services on multiple servers, wants to keep doing that for years, and needs high uptime. I have a bunch of personal services I run in VMs with Chef, and I'm excited to convert that over to Kubernetes, as it will make future OS upgrades and other maintenance easier. But my old setup ran for something like 6 years and it was just fine. For hobbyists whose hobbies don't include playing with cluster-scale ops tooling, I think it's perfectly fine to ignore Kubernetes. It's the new hotness, but it doesn't provide much value for them yet. They can wait a few years; by then the tooling will surely have improved for low-end installs.
From the application-developer side, I'd dispute this. I was told to use Docker + Kubernetes for a relatively small work project recently, and I was able to go from "very little knowledge of either piece of tech" to "I can design, build, and deploy my app without assistance" in about 1 week of actual study time, spread out over the course of the project. And although I have several years' experience, I'm not some super-developer or anything.
What surprised me most is how well-documented (for the most part) everything is. The Kubernetes and Docker sites have a ton of great information, and the CLIs are rich and provide a consistent interface for all the details about your environment. (To tell the truth, that alone makes the time investment worth it.)
After this, there's no way in hell I'm going back to Heroku or similar and trying to piece together their crappy, one-quarter-documented "buildpack" system. I'd take a Kubernetes-and-Docker-first PaaS at a reasonable markup any day of the week.
I don't know if I'm totally convinced by that argument alone, but it would be nice if every critical response didn't seem to assume that every hobbyist is born understanding systemd, ansible, packer, qemu, etc.
Right, but again I think the point being made is that, if those are skills you do want to learn, or plan on using later down the road, it's worth knowing that you can use K8s even at a small scale.
Obviously, in most cases it could be premature optimization, but for some people (including you), it can be fun to learn.
I don't think that is wrong. I do think it is probably overkill, and IMO it does introduce operational burden and complexity. That doesn't mean you shouldn't do it, though, if you're interested in exploring the technology, for example.
It is not like I haven't done it the "old" way. I spent many years doing hand deploys, making deployers, running Ansible/Chef. It is just that we always found we can never confidently update servers running many apps as it would step on other applications. So we'd just make new ones, test and switch. This was not an easy process either. Plus we'd encounter issues like oh someone didn't make a startup script or filled up /var with logs, or had something eat up all the memory. All of these operational problems are gone with K8s. I know what you are thinking "well you did it wrong". Yes sometimes developers do things wrong. But in container/K8s land that wrong stuff is contained, and if you don't do things "right" you can't even run.
So we had operational issues there. Now we have a universal platform that someone can ship their app anywhere and have it run the same. That is a huge win. All for no extra work.
The question isn't really whether you need dozens of machines, it's whether you can foresee eventually maybe needing dozens of machines.
Remember the bad old days when people said that relational databases were worthless because they "don't scale", that using Mongo and other NoSQL databases were practically a necessity for doing anything modern and "web-scale" because otherwise after you got your big break and you got popular you would need to keep up with all the new traffic and not crash? A lot of engineers have this tendency to worry about scalability long before it's ever a problem. Something about the delusions of grandeur incurred by people who got into engineering because they were inspired by great people building big things.
Starting out by running Kubernetes on a three-node cluster is actually the correct call for a small project if you can reasonably foresee needing to elastically scale your cluster in the future, and don't want to waste days or weeks porting to Kubernetes down the line to deal with your scalability problems that you foresaw having in the first place.
Again, that doesn't mean that Kubernetes is right for every hobbyist project. But there is definitely a (small) subset of hobbyist projects for which it is not overkill.
"Premature optimization is the root of all evil" -- Donald Knuth
Translating the old suggestions [1] to the realm of devops, I think the point really is: if you are fairly certain that your optimization (k8, docker and so on) will result in "better" code and practices right away, then you should do it. If not, you shouldn't.
I personally find this stuff to be way overkill in a lot of cases. Does Kubernetes really accelerate your development process? If you are a two-men startup, your objective is to find ways to deliver value as quickly as possible, not to play at being Facebook. When you become Facebook (or even just Basecamp), you will then have enough resources to do this optimization. But if you feel your development process is really so much better with K8 and friends (because it's what you used in a previous job or something), by all means go for it.
The number of projects that might scale up is much, much smaller than the number of projects that do. If I actually want my project to serve a zillion users, the right place for me to focus my effort is not on Kubernetes, but on user context interviews, user tests, and fast iteration based on the results of experiments.
I tried it about 6 months back with the intent of using it in a corporate prod environment and getting set up was... a massive pain in the ass to say the least - compared to the existing ansible set up. It was supposed to solve headaches, not cause them.
I wasn't impressed. I wouldn't be surprised if it ends up being "Angular 1.0" to someone else's react.
last year took, i think 2 days. my private one was up and running within ~1h, including writing the ansible role to first install binaries/dependencies and join the cluster as a worker node.
either you didn't use kubeadm to set it up or ... i have no idea how you could've possibly failed.
its pretty much
(all) ${packagemanager} install docker-ce kubectl kubelet kubeadm
(master) kubeadm init -> prints token
(node) kubeadm join ${token}https://github.com/kubernetes/kops
Be aware of this bug at scale ... its interesting
https://blog.quentin-machu.fr/2018/06/24/5-15s-dns-lookups-o...
I did use kubeadm. It required considerably more than just 3 simple steps required to get a basic working cluster up. Two days was more like it.
Personally I really like Docker Compose files - virtually no overhead to maintain alongside a handful of Dockerfiles coupled with really simple syntax for expressing the relationships between them. Containers themselves seems conceptually challenging for some newcomers in my experience (concepts like image immutability etc don't have many similar analogues I'd argue if you are new to containers, and I've seen some very experienced developers get stuck trying to map them conceptually to VM images which is not a good fit), but the payoff in the ease of deploying your work is huge. It's nothing a reasonable developer can't learn in a few hours though, and the documentation is pretty good.
I especially find Docker great for projects I worked on years ago - I no longer really need to keep track of how to install/configure the side project I haven't touched in age's software dependencies, just hit 'docker-compose up' and I'm running.
I also really like Docker-Compose as a replacement for things like Vagrant scripts to create developer environments in some scenarios - way less overhead than a vagrant script spinning up multiple VMs on your laptop, and generally much faster deployments.
Kubernetes doesnt manage the machines. It manages the applications on machines that are managed with something else.
You have to do something else to manage the machines
The difference is that if you did build it all by hand as the author said, if it ever scales, you're going to have double the job to make it scale.
It's all a question of: do I think my software will succeed?
If it's a hobby project that will never get big, it's not worth the hassle. If it actually has a chance of succeeding, the small added complexity of Kubernetes will pay dividends extremely quickly when the system needs to scale.
Even with as little as two machines, I'd argue k8s is already adding more value than managing those by hand. People can say otherwise because they're used to it, but being used to it is not the point of the discussion.
The author also talks about Ansible which is another piece of complexity that would be comparable with doing it in k8s. I'd argue you have less YAMLs with k8s than with Ansible for a small project.
The only argument I see for doing anything by hand today is if it's a play thing.
I don't know about your projects, but I'm my case most (all) of them doesn't really need any kind of scale. Hell, this blog has a tiny 5$ DO machine and is still happily serving traffic from HN. I do understand not all projects are small blog instances, though :)
I guess in my case I prefer to just keep it simple and see how far I go with that setup than spending time working on making the perfectly-scalable project that is never serving more than 2 requests per second. If it ever grows, I will need to work to make it scale, sure, but on the other hand that is a good problem to have.
Anyway, I understand this is pretty subjective and depends on how you think about your projects and your requirements, so I do understand there will be people both in agreement and disagreement.
However I read somewhere you had experience with Kubernetes, right? That means there is no extra work to learn the technology.
Now let's take your blog as an example. I'm gonna guess there's an official Docker image for whatever software you use and you could create an image, deployment + service + ingress in less than an hour for it (pretty much every example out there is about how to setup a blog, heh).
If you have to do all that manually through SSH, I'd argue it takes pretty much the same time and the complexity is the same. You will simply change the tools/concepts but won't be caught by manual gotchas.
With hobby projects for the vast majority of people, the answer is somewhere in the territory of "you can worry about that after it succeeds."
Kubernetes:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: test-ingress
spec:
rules:
- http:
paths:
- path: /testpath
backend:
serviceName: test
servicePort: 80
Nginx: location /testpath {
proxy_path http://127.0.0.1:8080
}
Which is less complex? Which is beta, and thus could be changed over time (it happens a lot). Which one requires major (and breaking) infrastructure updates every 3 months?> I'd argue you have less YAMLs with k8s than with Ansible for a small project.
Since you typically need one yaml document per K8s resource, and can describe multiple independent and idempotant actions in one Ansible document, I think this is easily demonstrable as false for small projects (and likely big projects as well).
The second is a configuration fragment that is useless by itself that would send all traffic to a single instance running on localhost.
Also we're talking simple projects, and simple projects are typically not distributed; typically don't need to be distributed.
That said, supporting multiple backends with different load balancing algorithms is also pretty simple to write as well.
How do I safely upgrade it without downtime? Ensuring that the new version starts up properly and can receive traffic before sending it requests and stopping the old one?
With k8s: kubectl set image deployment/my-deployment mycontainer=myimage:1.9.1 (or just use kubectl apply -f)
With your nginx config: ????
At which point, sure, use Kubernetes.
Still A single service on a single machine, how do I safely upgrade it?
A rolling deployment in k8s does work the same way on a single host with minikube as it does on a 1000 node cluster, but I'm still just asking about the single host case.
Depending on your OS-package's provided init script (here Ubuntu), it's as simple as `service nginx reload`, (`service nginx upgrade` if upgrading nginx itself).
Or skip the init script entirely with `/usr/sbin/nginx -s reload`.
Or
kubectl apply -f app.yaml
Which is less complex?
At minimum it requires good-enough health checks so that k8s can detect if the new config doesn't work, and automatically rollback, otherwise you're looking at "no downtime except when there's a mistake" situation.
...and to really check that the health check and everything else in your .yaml file actually works, you will probably have to spin up another instance just so that you can verify your config, unless you like debugging broken configs on live. Well, of course you can always fix your mistake and go "kubectl reaplce -f", but that kinda goes against the requirement of "no downtime".
I grant that k8s makes it easier to spin up a new instance for testing.
Lets not make it more difficult than it has to be.
Let's not pretend that blindly upgrading a package is the same thing as safely rolling out the new version of a service.
We've been using Kubernetes in production for almost two years now and I have yet to face a big API change that breaks everything. The core APIs are stable. There's a lot of new stuff added, but nothing that breaks backwards compatibility.
As you just said, if it's a simple project, you can upgrade the infrastructure by clicking "upgrade" on GKE. We've only ever hit problems when upgrading when using the bleeding edge stuff and the occasional bug (once since Kubernetes 1.1 to 1.10 for a large Rails app).
Regarding the yaml document per resource, I mean... that's spaghetti Ansible. If you want to have a proper Ansible setup you will have separate tasks and roles. If we're going down the route of just have "less files" you can have all the Kubernetes resources in a single YAML file. I would definitely not recommend that tho.
While Kubernetes is a lot more verbose, it is light years better than the Ansible jinja2 weird syntax. Even someone that never heard of Kubernetes can read that Ingress resource and guess what it does. If we're being really picky actually, the proxy_path should be pointing to some "test" thing that would have to be an upstream that would already make the NGINX config more obscure.
I feel like people just hate Kubernetes to avoid change. These arguments are never about Kubernetes' strengths or faults but about why "I think my way is better". You can always do things in millions of ways and they all have tradeoffs. The fact is: ROI on Kubernetes is a lot bigger than any other kind of manual setup.
I'll repeat what I said on another comment: the only reason to do anything by hand today is if it's a play thing
Are you running databases in Kubernetes? Do you have any existing on-prem infrastructure that you want to utilize (or are required to, because sunk costs) to integrate with Kubernetes?
Is you company a startup with no existing legacy application that you need to figure out how to containerize before you can even think about getting it into Kubernetes? We've seen benefits from running it, for sure, but I'm honestly not sure if the amount of work it took (and still takes) to make it work for us was worth the ROI.
Sometimes I feel like Kubernetes is a play by Google to get everyone using their methodology, but only they can provide the seamless experience of GKE.
Ansible has its warts, but it is great for managing and configuring individual servers.
In fact I've used Kubespray[1] to setup a cluster with Ansible before with mild success. Nothing production ready, but it's actually a good tool for that job. At the end of the day you can't run Kubernetes on Kubernetes :D
"Kubernetes allows you to scale simply!"*
"Kubernetes takes minutes to set up!"*
*When using GKE or another managed service.
Haven't had the experience myself outside of GKE so I can only imagine the complexity of it.
It is a young project still. My guess is that with some more time this will improve.
I was responding more to the comments I had been reading, not the premise of the article.
All deployments I have seen so far have been immutable infi scale webapps. That is easy.
However doing what you described is hard... anywhere.
Even if you do it all by hand it's going to be hard and most likely brittle. It might take a bit more time/effort to do that on Kubernetes but I would say you would end up being a better solution that can actually sustain change.
As stated before by many, Kubernetes is not a magic wand. But it does force you to build things in a way that can sustain change without a big overhead.
We all know that different tools have different purposes and I'm not advocating it's perfect by any means. All I'm trying to say is that this idea - that a lot of people have - that Kubernetes is 10x more complex than doing X by hand is an illusion.
IMHO it makes sense for most setups that have multiple micro-services that need to interact with each other. A single node cluster running a single container is kind of pointless; I agree. And you are not going to run much more than that on a micro instance. So, I agree with the main point of the article that this probably is not an appropriate setup for any kind of home setup unless of course you really want to have kubernetes (which would be a valid reason for attempting this).
If you run multiple microservices you have most of the problems that kubernetes solves out of the box and attempting to solve those by manually gobbling together bits of infrastructure outweighs the financial overhead of running kubernetes. So any moderately small setup where you are in any case going to have 2 or 3 machines running multiple containers, you probably should be looking at kubernetes.
So, if you are in Google or amazon, hosted kubernetes is definitely worth considering. You probably want a loadbalancer as well. So, at that point you are looking at ~50-100+$ per month anyway for a couple of instances, a LB and whatever else you need (e.g. RDS, S3, etc).
For anything running commercially, that's entirely defensible. Yes you can run cheaper on bare metal but people tend to forget all the hours doing devops stuff are also cost you. A day of a competent dev will easily run you kubernetes for quite some time. Unless your devs are super bored, make them spend their hours on more valuable stuff than reinventing wheels.
Well, it shouldn't be used but for very very few (if any) hobbyist projects.
Which is closer to this post, than the original article.
>But maybe I envision my side project turning into full-time startup some day.
Facebook managed this just fine as a simple PHP project on some guys laptop.
The original article concludes with "It's my contention that Kubernetes also makes sense for small deployments and is both easy-to-use and inexpensive today". This article contends that it's not at all easy to use and price-wise he hasn't compared like-with-like.
Exactly. Or maybe "I would love to advance my career and work for a larger company that is using Kubernetes, and I can get some hands on experience without breaking the bank."
"Do you want to do all of this because you think is fun? Or because you want to learn the technology? or just because? Please, be my guest! But really, would I do all of this just to run a personal project? No thanks."
I don't know what term to use but "full stack" apparently just means front end (html/css/js in browser) and backend (server software). Full stack is missing backup and restore, deployment, seamless upgrades (pushing new versions without down the service), scaling, testing infrastructure both front and backend, staging
As such, I have a hacked manual backup for my site. Anytime I want to update my site I have to take it offline for at least a moment. If any users were on it they lose their work. If it ever gets too much traffic I'll have to manually figure out how to scale it. It also took at least a week to get it where it is, as in a week doing stuff not my actual site but just learning how to deploy at all.
I can see no reason all of that can't be 100% provided out of the box and if Kubernetes is the path there I'm all for it.
Ideally I want to do something like
git clone complete-stack
install deps
edit server-main.js (or other lang)
edit client-main.js (or other lang)
deploy --init
Then I want edit server-main.js (or other lang)
edit client-main.js (or other lang)
stage
test
edit server-main.js (or other lang)
edit client-main.js (or other lang)
stage
test
deploy
And scale --num-servers=2
I would use it for any web based projects that aren't static servers.I'm told by people who provide tech support for people using Kubernetes that my dream of all of this being provided out of the box is about 10yr out.
Stateful workloads (the database servers) are not quite there yet and remains one of the most challenging parts of K8S. We are just starting to see Operators written for specific datastores (Mongodb, Postgresql, Redis, etc.)
I don't know about 10 years ... but it is not that turn-key right now, yet.
He says it's fine to do it if you want to learn the technology, but points out (rightly, I think) that if your concern is that you might need it at some point down the road, worry about it at some point down the road and not when you're trying to get started.
No! Although you could deploy it as a docker container easily.
Simple heuristic: how many containers and machines am I dealing with? More than one machine and one container? Consider moving to Docker Swarm or K8s. A single container? What is there to orchestrate?
Does that mean that Kubernetes should now be used for all hobbyist projects? No. If I'm thinking of playing around with a Raspberry Pi or other SBC, do I need to install Kubernetes on the SBC first? If I'm thinking of playing around with IoT or serverless, should I dump AWS- or GCE-proprietary tools because nobody will ever run anything that that can't run on Kubernetes ever again? If I'm going to play around with React or React Native, should I write up a backend just so I can have something that I can run in a Kubernetes cluster, because all hobbyist projects must run Kubernetes now, because it's cheap enough for hobbyist projects? If I'm going to play around with machine learning at home, buy a machine with a heavy GPU, figure out how to get Kubernetes to schedule my machine learning workload correctly instead of just running it directly on that machine, because uhhh maybe someday I'll have three such machines with powerful GPUs plus other home servers for all my other hobbyist projects?
No, no, no, no, no. Clearly.
But maybe I envision my side project turning into full-time startup some day. Maybe I see all the news about Kubernetes and think it would be cool to be more familiar with it. Nah, probably too expensive. Oh wait, I can get something running for $5? Hey, that's pretty neat!
Different people will use different solutions for different project requirements.