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> an operator can rebalance So, you're not talking about the same thing as OP, because one of the points being made here is that Kubernetes intentionally tries

> an operator can rebalance So, you're not talking about the same thing as OP, because one of the points being made here is that Kubernetes intentionally tries to get rid of human operators for day-to-day decision making. If you have a machine making operations decisions instead of humans, then a "bash-like shell" is worse than watch/subscribe mechanisms with full type safety, plus standard conventions for reporting events and communicating status.

henrydark 5y ago
If a human operator can make changes with a computer language, then a human programmer can make a computer operator that makes changes autonomously
- robertlagrant 5y ago
  Theoretically yes (of course) but Bash can make it tricky.
  - cturner 5y ago
    The purpose of the shell is to allow users to interact with the grid. You can't do this in a conventional OS shell. Example: if you are using /bin/sh on linux-host-a and want to affect something running on linux-host-b, you can't. In a SSI shell, you can affect resources from a set of machines from a single shell. You could offer something like shell scripting on that, but my system did not and there are better options. For example: have the resource manager expose a command that offers a DSL for making system-wide changes.
    - hobo_mark 5y ago
      > a DSL for making system-wide changes Like... Kubernetes? :)
cturner 5y ago
The paper presented declarative configuration as a contrast between the SSI approach and the k8s approach. I don't think it is. It is useful to have both the fitted arrangements and operator interaction. In addition to giving operators power to make changes in production, the command line is useful for development. Devs can develop in a one-host grid and interact with it in a repl-like way. Contrast this to traditional workflow where the deployment environment is quite different to the development environment. This encourages devs to work with the grain of the platform and discourages the "it works on my machine" dynamic.
ted_dunning 5y ago
Operator in the Kubernetes world is a different thing from a human operator of a computer system. The Kubernetes operator is software that continually compares what-is to what-should-be and makes a change that changes the state of the world to be closer to what-should-be. You specify what-should-be and (if all is well with the world) the system morphs itself into that in a more or less expeditious way. The original article described this pretty well.

henrydark 5y ago

If a human operator can make changes with a computer language, then a human programmer can make a computer operator that makes changes autonomously

robertlagrant 5y ago
Theoretically yes (of course) but Bash can make it tricky.
- cturner 5y ago
  The purpose of the shell is to allow users to interact with the grid. You can't do this in a conventional OS shell. Example: if you are using /bin/sh on linux-host-a and want to affect something running on linux-host-b, you can't. In a SSI shell, you can affect resources from a set of machines from a single shell. You could offer something like shell scripting on that, but my system did not and there are better options. For example: have the resource manager expose a command that offers a DSL for making system-wide changes.
  - hobo_mark 5y ago
    > a DSL for making system-wide changes Like... Kubernetes? :)

cturner 5y ago

The paper presented declarative configuration as a contrast between the SSI approach and the k8s approach. I don't think it is. It is useful to have both the fitted arrangements and operator interaction. In addition to giving operators power to make changes in production, the command line is useful for development. Devs can develop in a one-host grid and interact with it in a repl-like way. Contrast this to traditional workflow where the deployment environment is quite different to the development environment. This encourages devs to work with the grain of the platform and discourages the "it works on my machine" dynamic.

ted_dunning 5y ago

Operator in the Kubernetes world is a different thing from a human operator of a computer system. The Kubernetes operator is software that continually compares what-is to what-should-be and makes a change that changes the state of the world to be closer to what-should-be. You specify what-should-be and (if all is well with the world) the system morphs itself into that in a more or less expeditious way. The original article described this pretty well.