4 ms·

Kubernetes is a cloud operating system

29 points by nyellin 5y ago

btreecat 5y ago
It's the next LAMP stack
- mountainriver 5y ago
  Huh? Maybe the L in LAMP. It’s not a web sever or a database or a language
rektide 5y ago
This is a pretty ok framing. The author's already had to reply to some backblow against the idea but generally the big picture rings true enough, isnt horrifically wrong. But while true & a reasonable framing, this view doesnt cover the most important thing about the kubernetes "operating system". Yes unlike many other cloud systems Kubernetes has pretty wide coverage of concepts it has under it's roof. Versus serving a purpose or two well, it, like an OS is a fairly general & comprehensive platform, with the capabilities you'd need for most tasks, & built in OS extensibility via CRDs. This is all trye enough but still shy of how we ought think about Kubernetes versus other things, what came before, cloud or no cloud, os or other. Kubernetes is autonomic. Kubernetes, through a variety of controllers/operators, enacts all changes to the system. Rather than being, as most automation or other aoftware, a tool wielded by the user to make ends happen Kubernetes wields itself, & the user is simply stating what they want, makes their intent known, & Kubernetes makes sure that happens & stays that way. Taking people out of the loop of having to learn how to do computers, how to build a house themselves- Kubernetes knows how to build what you tell it. It's something so unlike software of any sort which came before, this ongoing (as opposed to single shot), autonomic (self maintaining), self-operating system, and I cannot contrast strongly enough how liberating it is to have the machines working for you, adjusting themselves, based off the manifest of inventory you've told it you want. It's a totally different operational paradigm, beyond just a system & having developed a weak internal agency (a control loop & it's suite of tools to stay on happy paths through the loop), and it means way way less figuring out how to run the dozens of various whirligigs and gizmos that comprise the computing environment. Kubernetes is more than an operating system; it is a self-governing control loop.
- chousuke 5y ago
  Kubernetes, by itself, does not really know how to "do" anything, but it provides a framework for writing components that do (controllers) in response to new resources being declared (I want to say "created" but nothing "real" exists until a controller does something) and updated.
  - nyellin 5y ago
    You can say created! It exists in etcd just hasn't been materialized in other ways yet.
    - chousuke 5y ago
      Yeah, I wanted to emphasize the difference between the kubernetes resource and the actual things that the controllers create based on the existence and attributes of those resources. I suppose "materialization" is a good word for it; you create a resource, and if it's something that actually needs something to execute, it is eventually materialized as a container scheduled to run on a kubelet, or an EBS volume, or some other actual thing that the appropriate controller creates. I like the core idea of Kubernetes (eventually consistent declarative infrastructure) though I'm not fully sold on the implementation and the tooling around it.
      - nyellin 5y ago
        Yeah fair point. Regarding the implementation and tooling, what's lacking in your opinion?
        chousuke 5y ago
        Well, some thoughts in no particular order: 0. YAML everywhere. Augh. 1. Vanilla kubernetes by itself doesn't really do much; everyone basically assumes you'll use a cluster in a cloud somewhere that comes with all kinds of add-ons and functionality on top of the default. If you want to run an on-premises cluster, once you start adding external components to a Kubernetes cluster to make it actually useful, it starts getting complicated. 2. I don't think configuration management of the resources you do put in a cluster is a fully solved problem, especially if you depend on CRDs. 3. kubectl being context-sensitive is rather annoying. You basically can't share a kubeconfig between two terminal sessions without severe danger of footgunning. 4. If you just use Helm packages with defaults, you'll end up running software with very collision-prone UIDs and security contexts, so two separate components that you deploy can end up running as the same user on a host. I don't think that's good security design, but the system doesn't encourage you to do the correct thing. 5. All the "easy" tooling is basically just "run this magic incantation and it will do things for you". The culture around how things are done seem to encourage ignorance about what you're actually deploying. Many operations also modify cluster state and thus should be managed and not done willy-nilly, but that's also ignored by default. See also #2 Kubernetes has its upsides (something like ArgoCD is very nice to use when set up properly) but I guess my main beef with it is that it can make things look easy that actually aren't, and mislead its users.
dam_broke_it 5y ago
Kubernetes is a dumpster fire floating down a flooded river....
- mountainriver 5y ago
  Thanks for your contribution
jjtheblunt 5y ago
i thought mesosphere was a cloud operating system, and it seemed to be a different take on the topic

29 points by nyellin 5y ago

btreecat 5y ago

It's the next LAMP stack

mountainriver 5y ago
Huh? Maybe the L in LAMP. It’s not a web sever or a database or a language

rektide 5y ago

This is a pretty ok framing. The author's already had to reply to some backblow against the idea but generally the big picture rings true enough, isnt horrifically wrong. But while true & a reasonable framing, this view doesnt cover the most important thing about the kubernetes "operating system". Yes unlike many other cloud systems Kubernetes has pretty wide coverage of concepts it has under it's roof. Versus serving a purpose or two well, it, like an OS is a fairly general & comprehensive platform, with the capabilities you'd need for most tasks, & built in OS extensibility via CRDs. This is all trye enough but still shy of how we ought think about Kubernetes versus other things, what came before, cloud or no cloud, os or other. Kubernetes is autonomic. Kubernetes, through a variety of controllers/operators, enacts all changes to the system. Rather than being, as most automation or other aoftware, a tool wielded by the user to make ends happen Kubernetes wields itself, & the user is simply stating what they want, makes their intent known, & Kubernetes makes sure that happens & stays that way. Taking people out of the loop of having to learn how to do computers, how to build a house themselves- Kubernetes knows how to build what you tell it. It's something so unlike software of any sort which came before, this ongoing (as opposed to single shot), autonomic (self maintaining), self-operating system, and I cannot contrast strongly enough how liberating it is to have the machines working for you, adjusting themselves, based off the manifest of inventory you've told it you want. It's a totally different operational paradigm, beyond just a system & having developed a weak internal agency (a control loop & it's suite of tools to stay on happy paths through the loop), and it means way way less figuring out how to run the dozens of various whirligigs and gizmos that comprise the computing environment. Kubernetes is more than an operating system; it is a self-governing control loop.

chousuke 5y ago
Kubernetes, by itself, does not really know how to "do" anything, but it provides a framework for writing components that do (controllers) in response to new resources being declared (I want to say "created" but nothing "real" exists until a controller does something) and updated.
- nyellin 5y ago
  You can say created! It exists in etcd just hasn't been materialized in other ways yet.
  - chousuke 5y ago
    Yeah, I wanted to emphasize the difference between the kubernetes resource and the actual things that the controllers create based on the existence and attributes of those resources. I suppose "materialization" is a good word for it; you create a resource, and if it's something that actually needs something to execute, it is eventually materialized as a container scheduled to run on a kubelet, or an EBS volume, or some other actual thing that the appropriate controller creates. I like the core idea of Kubernetes (eventually consistent declarative infrastructure) though I'm not fully sold on the implementation and the tooling around it.
    - nyellin 5y ago
      Yeah fair point. Regarding the implementation and tooling, what's lacking in your opinion?
      - chousuke 5y ago
        Well, some thoughts in no particular order: 0. YAML everywhere. Augh. 1. Vanilla kubernetes by itself doesn't really do much; everyone basically assumes you'll use a cluster in a cloud somewhere that comes with all kinds of add-ons and functionality on top of the default. If you want to run an on-premises cluster, once you start adding external components to a Kubernetes cluster to make it actually useful, it starts getting complicated. 2. I don't think configuration management of the resources you do put in a cluster is a fully solved problem, especially if you depend on CRDs. 3. kubectl being context-sensitive is rather annoying. You basically can't share a kubeconfig between two terminal sessions without severe danger of footgunning. 4. If you just use Helm packages with defaults, you'll end up running software with very collision-prone UIDs and security contexts, so two separate components that you deploy can end up running as the same user on a host. I don't think that's good security design, but the system doesn't encourage you to do the correct thing. 5. All the "easy" tooling is basically just "run this magic incantation and it will do things for you". The culture around how things are done seem to encourage ignorance about what you're actually deploying. Many operations also modify cluster state and thus should be managed and not done willy-nilly, but that's also ignored by default. See also #2 Kubernetes has its upsides (something like ArgoCD is very nice to use when set up properly) but I guess my main beef with it is that it can make things look easy that actually aren't, and mislead its users.

dam_broke_it 5y ago

Kubernetes is a dumpster fire floating down a flooded river....

mountainriver 5y ago
Thanks for your contribution

jjtheblunt 5y ago

i thought mesosphere was a cloud operating system, and it seemed to be a different take on the topic