7 ms·

Why are you putting logic in the config in the first place? Just let it be data.

DonHopkins 7y ago
That's like saying that God existed before creating the universe. Then you have to ask who created God? And if God was created only from data and not any logic, then the config file must have been really huge and unmaintainable.
- SomeOldThrow 7y ago
  Do you have an example of when logic would help a configuration file? Their value and use are entirely dependent on the context. Also I can't make a head or tail of your statement, no offense intended—I can make out parts, but the whole just has no meaning to me.
  - DonHopkins 7y ago
    Given any non-trivial data-only config file, it will always grow to the point that you'll end up needing to generate it automatically with logic. And that goes double for God's config file.
    - SomeOldThrow 7y ago
      Do you have an example? I don't think I've ever needed to generate a config automatically (except in niche cases like generating configs for services in chef), and if I'm understanding correctly, nothing proposed in this thread would help with that scenario. I suspect you're front-loading a lot of logic from the app bootup into the config file, and I'm not sure what you stand to gain conflating those two things. Like—what's the execution order of a config file? Can you refer to a value later in the file? If so, how does it determine which value is executed before the next? If not, how do you setup circular dependencies—can you redefine config values halfway through a file? If not, you're gonna have to fall back on at-boot pre-processing anyway with sufficient complexity, so just treat a config like dumb data to begin with and do all your logic in the bootup and put all the values/whatever in the config file. And god knows, I would be strongly tempted to murder an engineer that introduced a config file capable of rewriting itself—that engineer has clearly never needed to debug another person's shitty code before.
      - DonHopkins 7y ago
        I've developed programs with tens of thousands of lines of expanded JSON in their config files. No fucking way I'm maintaining all that by hand as pure data. See: https://news.ycombinator.com/item?id=20735231 https://news.ycombinator.com/item?id=20735231 Also: https://en.wikipedia.org/wiki/Don%27t_repeat_yourself https://en.wikipedia.org/wiki/Don%27t_repeat_yourself and https://en.wikipedia.org/wiki/Single_source_of_truth https://en.wikipedia.org/wiki/Single_source_of_truth The opposite of DRY (Don't Repeat Yourself) is WET (Write Everything Twice or We Enjoy Typing or Waste Everyone's Time) -- but twice could be ten times or more, there's no limit. Writing it all out again and again by hand as pure literal data, and hoping I didn't make any typos or omissions in each of the ten repetitions, without some sort of logical algorithmic compression and abstraction, would be idiotic.
        SomeOldThrow 7y ago
        > I've developed programs with tens of thousands of lines of expanded JSON in their config files. To what end? I don't get what you could possibly be putting in these files that could consume so much space without refactoring.
        DonHopkins 7y ago
        I posted some examples above. (Or maybe it's below. The long message with lots of links.)
      - DrJosiah 7y ago
        This thread hurts so bad. I never used helm / kubernetes before 3 months ago. Not 2 weeks ago I needed to loop in a helm config file in order to basically say "all this same config, libraries, etc., just run this other command instead" ... because someone who makes those decisions had ~100 lines of environment-injected configuration + boilerplate in the yaml that I couldn't get rid of, needed, and would have otherwise needed to copy / paste. Since then, those environment variables have been pulled out into a different file (refactoring!), and now we replaced a loop over 100 lines of config, with 2x sets of 15-20 lines of config boilerplate. Better, but still a lot of bull. I don't know what the right answer is, because we've got less helm templating bullshit in there, but we still need boilerplate. Because it's not like I can tear down an entire kubernetes + helm infrastructure because I don't like how the config files are written. Configs / config generation is hard, and generally awful. If you don't see it that way, congratulations; you're either a genius in your field, you've got not enough experience, and/or you're wrong. If you believe it's easy, and we're all missing something - please, by all means, write a book on how / why configurations aren't as hard as the rest of us say they are. Best of luck to you.
  - DonHopkins 7y ago
    It sounds like you're assuming that configurations are only created before running a program. But you can also create them while programs are running, to configure dynamically created objects or structures, too. And you can send those configurations as messages, to implement, for example, a distributed network object system for a multi player game. So you may be programmatically creating hundreds of dynamic parameterized "configuration files" per second.

That's like saying that God existed before creating the universe. Then you have to ask who created God? And if God was created only from data and not any logic, then the config file must have been really huge and unmaintainable.

SomeOldThrow 7y ago
Do you have an example of when logic would help a configuration file? Their value and use are entirely dependent on the context. Also I can't make a head or tail of your statement, no offense intended—I can make out parts, but the whole just has no meaning to me.
- DonHopkins 7y ago
  Given any non-trivial data-only config file, it will always grow to the point that you'll end up needing to generate it automatically with logic. And that goes double for God's config file.
  - SomeOldThrow 7y ago
    Do you have an example? I don't think I've ever needed to generate a config automatically (except in niche cases like generating configs for services in chef), and if I'm understanding correctly, nothing proposed in this thread would help with that scenario. I suspect you're front-loading a lot of logic from the app bootup into the config file, and I'm not sure what you stand to gain conflating those two things. Like—what's the execution order of a config file? Can you refer to a value later in the file? If so, how does it determine which value is executed before the next? If not, how do you setup circular dependencies—can you redefine config values halfway through a file? If not, you're gonna have to fall back on at-boot pre-processing anyway with sufficient complexity, so just treat a config like dumb data to begin with and do all your logic in the bootup and put all the values/whatever in the config file. And god knows, I would be strongly tempted to murder an engineer that introduced a config file capable of rewriting itself—that engineer has clearly never needed to debug another person's shitty code before.
    - DonHopkins 7y ago
      I've developed programs with tens of thousands of lines of expanded JSON in their config files. No fucking way I'm maintaining all that by hand as pure data. See: https://news.ycombinator.com/item?id=20735231 https://news.ycombinator.com/item?id=20735231 Also: https://en.wikipedia.org/wiki/Don%27t_repeat_yourself https://en.wikipedia.org/wiki/Don%27t_repeat_yourself and https://en.wikipedia.org/wiki/Single_source_of_truth https://en.wikipedia.org/wiki/Single_source_of_truth The opposite of DRY (Don't Repeat Yourself) is WET (Write Everything Twice or We Enjoy Typing or Waste Everyone's Time) -- but twice could be ten times or more, there's no limit. Writing it all out again and again by hand as pure literal data, and hoping I didn't make any typos or omissions in each of the ten repetitions, without some sort of logical algorithmic compression and abstraction, would be idiotic.
      - SomeOldThrow 7y ago
        > I've developed programs with tens of thousands of lines of expanded JSON in their config files. To what end? I don't get what you could possibly be putting in these files that could consume so much space without refactoring.
        DonHopkins 7y ago
        I posted some examples above. (Or maybe it's below. The long message with lots of links.)
    - DrJosiah 7y ago
      This thread hurts so bad. I never used helm / kubernetes before 3 months ago. Not 2 weeks ago I needed to loop in a helm config file in order to basically say "all this same config, libraries, etc., just run this other command instead" ... because someone who makes those decisions had ~100 lines of environment-injected configuration + boilerplate in the yaml that I couldn't get rid of, needed, and would have otherwise needed to copy / paste. Since then, those environment variables have been pulled out into a different file (refactoring!), and now we replaced a loop over 100 lines of config, with 2x sets of 15-20 lines of config boilerplate. Better, but still a lot of bull. I don't know what the right answer is, because we've got less helm templating bullshit in there, but we still need boilerplate. Because it's not like I can tear down an entire kubernetes + helm infrastructure because I don't like how the config files are written. Configs / config generation is hard, and generally awful. If you don't see it that way, congratulations; you're either a genius in your field, you've got not enough experience, and/or you're wrong. If you believe it's easy, and we're all missing something - please, by all means, write a book on how / why configurations aren't as hard as the rest of us say they are. Best of luck to you.
- DonHopkins 7y ago
  It sounds like you're assuming that configurations are only created before running a program. But you can also create them while programs are running, to configure dynamically created objects or structures, too. And you can send those configurations as messages, to implement, for example, a distributed network object system for a multi player game. So you may be programmatically creating hundreds of dynamic parameterized "configuration files" per second.