Posted by carlos-menezes 2 days ago
Some genius decided that, to make time input convenient, YAML would parse HH:MM:SS as SS + 60×MM + 60×60×HH. So you could enter 1:23:45 and it would give you the correct number of seconds in 1 hour, 23 minutes, and 45 seconds.
They neglected to put a maximum on the number of such sexagesimal places, so if you put, say, six numbers separated by colons like this, it would be parsed as a very large integer.
Imagine my surprise when, while working at a networking company, we had some devices which failed to configure their MAC addresses in YAML! After this YAML config file had been working for literal years! (I believe this was via netplan? It's been like a decade, I don't remember.)
Turns out, if an unquoted MAC address had even a single non-decimal hex digit, it would do what we expected (parse as a string). This is not only by FAR the more common case, but also we had an A in our vendor prefix, so we never ran into this "feature" during initial development.
Then one day we ran out of MAC addresses and got a new vendor prefix. This time it didn't have any letters in it. Hilarity ensued.
(This behavior has thankfully been removed in more recent YAML standards.)
index.html.pl is where the problem started and the reason why the officially recommended file extension for Perl files used to be (still is?) *.plx.
I don't have the Camel book at hand, but Randal Schwartz's Learning Perl 5th edition says:
"Perl doesn't require any special kind of filename or extension, and it's better not to use an extension at all. But some systems may require an extension like plx (meaning PerL eXecutable); see your system's release notes for more information."
The YAML document from hell (566 points, 2023, 353 comments) https://news.ycombinator.com/item?id=34351503
That's a Lot of YAML (429 points, 2023, 478 comments) https://news.ycombinator.com/item?id=37687060
No YAML (Same as above) (152 points, 2021, 149 comments) https://news.ycombinator.com/item?id=29019361
I never liked the provisioning overlap Ansible has with Terraform, so it makes sense to me: provisioning servers with tf, configure them with another tool, whether it’s ansible or pyinfra. Well, at least in theory
Which Ansible is absolutely atrocious at, so that makes sense. Use the best tool for the job (so Terraform, maybe Pulumi/tfcdk if you hate your future self/future teammates for infra.
Even more fun is if you then run your Kubernetes cluster on top of a VM orchestrator such as vSphere, that way you have multiple layers of stateful control planes and compute orchestrators fighting each other.
If only they had had ⊥ and ⊤ somewhere on their keys to work with Booleans directly while designing the languages. In another branch of history, perchance.[1]
[1] https://en.wikipedia.org/wiki/APL_(programming_language)#/me...
Boolean and propositional logic is not the same.
"Yeah but it's so convenient"
"Yeah but the benefit of yaml is that you don't need quotes everywhere so that it's more human readable"
DON'T
00,01,02,03,04,05,06,07,OH SHIT
It's not that bad, because you can explicitly turn that behavior off, but ask me how I know =(
Ansible has a pretty common issue with file permissions, because pretty much every numeric representation of a file mode is a valid number in YAML - and most of them are not what you want.
Sure, we can open up a whole 'nother can of worms if we should be programming infrastructure provisioning in YAML, but it's what we have. Chef with Ruby had much more severe issues once people started to abuse it.
Plus, ansible-lint flags that reliably.
See also p95 but the same couple of users always see the p99 time, due to some bug.
The 1.2 spec just treats all scalar types as opaque strings, along with a configurable mechanism[0] for auto-converting non-quoted scalars if you so please.
As such, I really don't quite grok why upstream libraries haven't moved to YAML 1.2. Would love to hear details from anyone with more info.
[0]:https://yaml.org/spec/1.2.2/#chapter-10-recommended-schemas
This:
#/media/File:APL-keybd2.svg){kind=link}
isRegistered: true
accountStatus: "UNREGISTRED"And for this reason, "logging: false" would be clearer than "logging: no" to represent "I do not want logging".
Don’t use bool at all.
While it has the YAML-like significant whitespace, it looks nice because it doesn't try to be clever.
1. Specify in the key
loggingEnabled: false
logging: disabledThat sounds like a breaking change that rendered old YAML documents to be parsed differently.
The tag schema used is supposed to be modifiable folks!
And why anyone would still be using 1.1 at this point is just forehead palming foolishness.
The yaml.orf website also lists a bunch of implementations, with about 1/3 supporting 1.2. I'm guessing that the users of those libraries just happily hum along and we never hear from them!
The issue is that downstream consumers of popular languages with a vocal community here on HN tend to just pull in libyaml, PyYAML being the major offender in my mind.
I've only seen it used for configuration.
Don't ask me why though, might have something to do with how it's written like a python file, no user would want to write their data in yaml format.