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Comment by orf | Hacker News Reader

Would you rather it had a JSON dependency to parse a config file, or yet another poorly thought out, ad-hoc homegrown config file format?

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JSON is a terrible configuration format since it doesn't support comments.

Ok. Do you want to now add anything relevant to the comment you’re replying to?

As a user, I always prefer the bespoke configuration file format, provided it has comments explaining what each configuration option does.

Its an entirely relevant response...they are saying what you call a poorly thought out adhoc format is still better than json in any form or dependency.

Ironically your snark isnt relevant.

Could be instead YAML or TOML. The point wasn’t specifically and only a JSON dependency, it was a dependency in general to do something useful and standardised

> Would you rather it had a JSON dependency to parse a config file, or yet another poorly thought out, ad-hoc homegrown config file format

Ok, but you didn't write that, and thus they responded as such. Snark was still unnecessary; they made a simple statement in reply.

> yet another poorly thought out, ad-hoc homegrown config file format

OpenBSD style ntpd.conf:

    servers 0.gentoo.pool.ntp.org
    servers 1.gentoo.pool.ntp.org
    servers 2.gentoo.pool.ntp.org
    servers 3.gentoo.pool.ntp.org

    constraints from "https://www.google.com"

    listen on *

I mean, there's always the possibility that they used a common, well known and pretty decent config file format. In this particular case, this shouldn't be the thing that differentiates your ntpd implementation anyways.

That config file perfectly illustrates the point. There's no need for it to be custom, and require me to waste time learning its syntax when it could just be JSON or TOML. Honestly I would even take YAML over that and YAML is the worst.

You still have to learn the syntax even if it is expressed in json or yaml. Perhaps stating the obvious, but not every json object is a valid ntp configuration.

The configuration object will always and by definition be proprietary to ntp. Expressing it as plain text allows for a trivial parser, without any of the security implications of wrapping it in a general language language ("should this string be escaped?", "what should we do with invalid utf8?").

The more simple format has survived over thirty years, is trivial to parse by anyone, and does not bring any dependencies that needs maintaining. That should count for something.

Sure you have to learn how to configure things but you don't have to learn basic syntax like "how do I escape a string".

The fact that it has survived tells you nothing other than it's not so completely awful that someone went through the pain of fixing it. That doesn't mean it is good. There are plenty of awful things that survive because replacing them is painful due to network effects. Bash for example.

It uses TOML for configuration.

Cool, thats why this is a hypothetical question

Poorly thought out, ad-hoc homegrown config file format, please. Every time.

1. Code doesn't change at the whims of others.

2. The entire parser for an INI-style config can be in about 20 lines of C

3. Attacker doesn't also get to exploit code you've never read in the third party dependency (and its dependencies! The JSON dependency now wants to pull in the ICU library... I guess you're linking to that, too)

4. Complexity of config file formats are usually format-independent, the feature-set of the format itself only adds complexity, rather than takes it away. To put it another way, is this any saner...

    {"user":"ams","host":"ALL","runas":["/bin/ls","/bin/df -h /","/bin/date \"\"","/usr/bin/","sudoedit /etc/hosts","OTHER_COMMANDS"}

... than ...

    # I may be crazy mad but at least I can have comments!
    ams ALL=/bin/ls, /bin/df -h /, /bin/date "", /usr/bin/, sudoedit /etc/hosts, OTHER_COMMANDS

All the magic in the example is in what those values are and what they imply, the format doesn't improve if you naively transpose it to JSON.

An example of an NTP server's config:

    # I can have comments too
    [Time]
    NTP=ntp.ubuntu.com
    RootDistanceMaxSec=5
    PollIntervalMinSec=32
    PollIntervalMaxSec=2048

If you just want key-value pairs of strings/ints, nothing more complex is needed. Using JSON is overdoing it.

1. I can pin my json parser dependency and literally never update it again

2. And how many times have we seen 20 lines of C backfire with some sort of memory safety issue.

3. First off, i'd go out on a limb and say the number of attacks from a well-established (or even a naive one) rust json parsing library is dwarfed by the number of attacks from adhoc config parsers written in C with some overlooked memory safety issue.

4. Usually being the key word, tons of adhoc config formats have weird shit in them. With json (or yaml/toml) you know what you're getting into and you immediately know what you're able and unable to do.

I feel like using the incomprehensibly error-prone and inscrutable sudoers format as an example kinda argues against your point.

(I do agree that JSON is a terrible configuration file format, though.)

My argument was not that sudoers is good - it's crazy overcomplicated.

My argument was data interchange format standards are orthogonal to config files. They don't have the same goals.

A programmer who thinks "I'll use JSON|YAML|TOML for my config file" - well, you didn't solve your first problem (what should the config look like, in a way that makes sense and is easily readable, understandable, updateable by the user) and you added a second problem before you even started solving the first - whatever your config looks like, it now also has to be 100% compliant with some data interchange format and support all its features, and that's going to require a lot of code - and then we get into whether you write the compliant parser/generator, or if someone else does and you do/don't audit every line of it. And then on top of that you add an additional pile of code to parse/generate whatever your actual config format is.

I once saw an .ini for a log parser:

    [Alarm]
    Name=Nginx Errors
    Pattern="[error] <pid>#<tid>: <message>"

The thing worked. Without any errors. And yet it took:

    Pattern="[error] <pid>

..and then considered the rest of the line a comment. It didn't even error on the fact that the quotes were not closed.

Hand-rolling config formats is hard.

Yeah try adding a git alias with quotes... I ended up reading the source code to figure out wtf it was doing.

Why isn't there a decent parser in the standard library? More than 50% of programs will probably touch json at this point.

Rust's stdlib is (at least notionally) forever. Things in the standard library (including core and alloc) get deprecated but must be maintained forever, which means that "at this point" isn't enough.

In 2003 those programs would have used XML, in 1993 probably .INI files. Are you sure that despite all its shortcomings JSON is the end of history? I don't believe you.

If you want "at this point" you can, as software does today, just use a crate. Unlike the stdlib, if next week Fonzie files are huge and by 2026 "nobody" is using JSON because Fonzie is cool, the JSON config crate merely becomes less popular.

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