So, it's been a while since I've been working on my current project and I've never had the "luck" to touch the legacy project wrote in PHP, until this week when I got my first issue.

And damn, this goddamn issue. It was a bug, a very strange bug, that only happens in production and that nobody has any idea what was happening, so yeah, I didn't have anyone to ask and I got less time than usual ( because Thanksgiving ).

And thus, I have no starting point, no previous knowledge on PHP and less time! I expected a very fun week 😀 and it was beyond my expectations.

First I tried to understand what might be causing the issue, but there wasn't any real clue to star with, so no choice, time to read the flow on the code and see what are they're doing and using ( 1k line files, yay, legacy ). Luckily I got some clues, we're using a cookie and a php session variable for the session, ok, let's star with the session variable. Where it's that been initialize ? Well, spoiler alert, I shouldn't start with that, because my search end up in the login method of the API that set a that variable and for some reason in the front end app it was always false and that lead me to think that some of the new backend functions were failing, but after checking the logs I got no luck.

Ok, maybe the cookie it's the issue, I should try open the previous website on the brow...redirect to new project login, What? Why ? I ask around and it's a new feature push on Monday, ok I got Chrome Dev tools I can see which value of the cookie it's been set and THERE IT WAS it has a wrong domain! After 2 days ( I resume a lot of my pain ) I got what I've been looking for, so now I should be able to fix the bug. Then where is the cookie initialized ? In the first file the server hits whenever you tried to enter any page of the app, ok, I found the method, but it's using a function that process the domain and sets it correctly? wtf ? Then how in heaven do I get the incorrect domain ? Hello? Ok, relax, you still have one more day to fix this, let's take it easy.

Then, at the end of the Wednesday, nope I still have no clue how this is happening. I talked with the Devops guy and he explain me how this redirection happens and with what it depends on, I followed the PHP code through and nothing, everything should works fine, sigh. Ok I still have 2 days, because I'm not from US and I'm not in US, so I still have time, but the Sprint is messed up already, so whatever I'm gonna had done this bug anyhow.

Thursday ! I got sick, yay, what else could happen this week. Somehow I managed to work a little and star thinking in what external issue could affect the processing, maybe the redirection was bringing a wrong direction, let's talk with the Devops guy again, and he answer me that the redirection it was being made by PHP code, IN A FILE THAT DOESN'T EXIST IN THE REPOSITORY, amazing, it's just amazing. Then he explained me why this file might be missing and how it's the deployment of this app ( btw the Devops guy it's really cool and I will invite him a beer ) . After that I checked the file and I see a random session_star in the first line of the code, without any configuration, eureka ! There was the cause and I only need to ask someone If that line it's necessary anymore, but oh they're on holiday, damn, well I'll wait till Monday to ask them. But once and for all that bug was done for ! 🎉

What do I learn ? PHP and that I don't want any more tickets of PHP 😆.

Be me:

Said on Friday the API was looking unstable.

Get a text on Sunday afternoon that SHTF.

Guess what got made a priority on Tuesday?