Allow build ulimit to be defined in the compose file

[guilhermenovais]

Description

Currently, it is only possible to set ulimits for the container execution, but I also need to set it for the build, so I need to manually build the image using docker build -t _example_ --ulimit nofile=65536:65536 . and then run docker compose up, instead of just running docker compose up --build.

It would be nice if there was an element inside the build element that allowed ulimits to be defined.
This is what I have in mind:

version: '3'
services:
  example:
    image: _exemple_
    build:
      context: .
      ulimits:
        nofile:
          soft: 65536
          hard: 65536

[Torxed]

Can confirm, this is a pain in the build process when fakeroot iterates over all file descriptors for potential childs, as it can take forever.

Having a way to manipulate nofile parameters during build, but not execution would help speed up builds from 168.7s -> 0.7s.

[ViliusS]

@ndeloof just for the record, which version will have this?

[ndeloof]

v2.23.1 to be release later this week will have the fix

[Torxed]

Thank you for the quick and awesome work, looking forward to this one :)