[FEATURE] Add variables support

[mhalano]

Is your feature request related to a problem? Please describe.
I have many tasks related to NVIDIA drivers for Linux, like what is the latest version available on the website, what packages are available on Ubuntu, etc.
There is one thing that changes time to time that is the driver's series. Today is 570, but tomorrow version 575 can be released.
Each release I have update my jobs on description, urls and sometimes filters, to indicate the newest series.

Describe the solution you'd like.
A way to define a variable on YAML, like Jinja2, that I can put in everything in the jobs.yaml file.
Also would be nice to have a job setting this value, so I can query the website, process it, and return the series so everything is done automatically, without me having to change the series number.

Describe alternatives you've considered.
Thought about using anchors and references, standard on YAML, but I can't put in the middle of a value, like a url or name, so wouldn't work. It should be something like Jinja2 template.

[mborsetti]

Hi Marcos,

I can't think of an easy way to implement something like this and I am struggling to understand the use case. Could you kindly provide URL examples where e.g. 570 became 575? Maybe there's another (easier) way. Thanks.

[mhalano]

For example: here you can see when new NVIDIA driver versions become available on Ubuntu. You can say the directory name follows a standard, but what the value that will come next is a mystery.
Here is the page that changes each time a new version is released. So the idea would get the latest series version and use as a variable to be able for new versions. I have other cases, like when I already know the directory name, I check if there are packages for i386 architecture, that indicates multi-arch support available.

[mhalano]

Can you pre-process the jobs.yaml file using Jinja2? The problem is how to get the values to fill the values.

[mhalano]

@mborsetti I found in my jobs.yaml a part that could help you to get more context.
Here it's the piece of code that checks when DEB packages for i386 are added to the repository (I have a couple of them, actually):

name: Support for i386 on NVIDIA 570 series in Ubuntu repository available
url: http://archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-graphics-drivers-570/#1
additions_only: true
filters:
  - html2text: strip_tags
  - keep_lines_containing: i386
    striplines:

You can see here that when they release a newer driver series, 575, lat's say, I have to come here and change the title and the URL from 570 to 575 to keep working with newer versions.
I have many of these checks related to NVIDIA driver versions, but with this one you can understand how a variable would be useful.
It would be helpful to set a variable like nvidia_series: 570 so I can change in one place, or if one job could set the value of the variable.
Maybe a combo between a hook to get and set the correct value and a Jinja2 template to fill the values in the jobs.yaml file would work. Perhaps also a possibility to run one specific job before all the others, and get the value to put in the variable that will be set by the Jinja2 template. During the main execution, of course, these jobs marked as pre-jobs wouldn't run.
What do you think, this is doable?