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Post Mortem: A single whitespace character
11–20 of 209 posts
Re: Post Mortem: A single whitespace character
#12I've had the same issues when developing with Flask in Python. I forgot to URL encode some query parameters and it worked fine with the local HTTP server.
But when I put nginx in front as a proxy, it denied all requests.
Re: Post Mortem: A single whitespace character
#13The Server: cowboy tag is from an Erlang web server: https://github.com/ninenines/cowboy/blob/master/src/cowboy_p... I'm guessing around here would be interesting to add a test case to handle. As far as whose server this is? I'd guess Heroku or AWS, though it's plenty possible T-Mobile could have devised some proxy to inspect traffic, but seems unlikely they would do so with Cowboy?
It's simple enough to single out Heroku:
$ cat Re: Post Mortem: A single whitespace character
#14Slightly off-topic, but this is why dev posts like this are important. I didn't know eatabit.com was a thing, it it sounds like a great service.
Re: Post Mortem: A single whitespace character
#15This very example -- requests were technically illegal all the time without devs realizing, but something in the stack changed to start rejecting them -- demonstrates the fallacy of the "be liberal in what you accept, strict in what you issue" principal. If all the web servers involved had been strict in rejecting the illegal request from the start, they would have noticed the bug in development before deploying to f…
Doesn't it just demonstrate that you shouldn't switch from being liberal to being strict?
For it to hold up, you need to provide the further argument that you frequently need to switch from liberal to strict.
Re: Post Mortem: A single whitespace character
#16It scares me to think all of these requests run over unencrypted HTTP.
Why? it's just pizza
Re: Post Mortem: A single whitespace character
#17This very example -- requests were technically illegal all the time without devs realizing, but something in the stack changed to start rejecting them -- demonstrates the fallacy of the "be liberal in what you accept, strict in what you issue" principal. If all the web servers involved had been strict in rejecting the illegal request from the start, they would have noticed the bug in development before deploying to f…
> the fallacy of the "be liberal in what you accept, strict in what you issue" principal
The market (players) (can) manipulate it to create an (perceived) competitive advantage.
It's also a source where "evil" in IT comes from.
Re: Post Mortem: A single whitespace character
#18This very example -- requests were technically illegal all the time without devs realizing, but something in the stack changed to start rejecting them -- demonstrates the fallacy of the "be liberal in what you accept, strict in what you issue" principal. If all the web servers involved had been strict in rejecting the illegal request from the start, they would have noticed the bug in development before deploying to f…
I don't agree that "be liberal in what you accept, strict in what you issue" is a fallacy. The client actually failed to adhere to the "be strict in what you issue" principal, just as the Cowboy was not liberal in accepting. All software will sooner or later exhibit bugs or be stricter or more lenient about a standard.
I think the fallacy is to assume that once stuff works in production, only your changes can trigger a bug. There's way too much software involved in a standard webserver stack to assume anything about it. Any patch, any update to software or devices not under your control has the potential to break your stack. The thing the OP did was the right thing: Monitor, monitor, monitor.
Re: Post Mortem: A single whitespace character
#19This very example -- requests were technically illegal all the time without devs realizing, but something in the stack changed to start rejecting them -- demonstrates the fallacy of the "be liberal in what you accept, strict in what you issue" principal. If all the web servers involved had been strict in rejecting the illegal request from the start, they would have noticed the bug in development before deploying to f…
This doesn't demonstrate a fallacy in "be liberal in what you accept" any more than closed source software demonstrates fallacies in Linus's Law.
The problem wasn't liberal acceptance, it was that liberal acceptance ended when Cowboy was added to the mix.
Strict acceptance would have shown the error earlier, but continued liberal acceptance would have allowed continued functionality.
Re: Post Mortem: A single whitespace character
#20It scares me to think all of these requests run over unencrypted HTTP.
Why? it's just pizza
Pizza has been used as a tool of harassment in the past. People order lots of pizza from different places for the victim, who then has to deal with a bunch of angry pizza drivers and being black-listed from those pizza places.
Pizza drivers are often the victims of crime. Not only for the small amounts of cash that they carry, but sometimes just for the pizzas.
edit: I should say that my comment here was a kneejerk reaction to "it's just pizza", and has nothing to do with how eatabit.com deals with this kind of harassment. i agree with other commenters that blog posts like these are a great way to promote the company.