Enhancement: core.excludesfile .gitignore (file) support

[hakre]

Describe feature

the git (config) core.excludesfile sets a user-wide core ".gitignore" that applies to all projects.

currently act's .gitignore feature does not take it into account, paths ignored by it are copied into the container.

Backgound: core.excludesfile git-config Setting

from the git-book (Customizing Git Configuration):

core.excludesfile
You can put patterns in your project’s .gitignore file to have Git not see them as untracked files or try to stage them when you run git add on them, as discussed in Ignoring Files.

But sometimes you want to ignore certain files for all repositories that you work with. If your computer is running macOS, you’re probably familiar with .DS_Store files. If your preferred editor is Emacs or Vim, you know about filenames that end with a ~ or .swp.

This setting lets you write a kind of global .gitignore file. If you create a ~/.gitignore_global file with these contents:

*~
.*.swp
.DS_Store

…and you run git config --global core.excludesfile ~/.gitignore_global, Git will never again bother you about those files.

another reference is core.excludesFile on the git-config(1) page:

core.excludesFile
Specifies the pathname to the file that contains patterns to describe paths that are not meant to be tracked, in addition to .gitignore (per-directory) and .git/info/exclude. Defaults to $XDG_CONFIG_HOME/git/ignore. If $XDG_CONFIG_HOME is either not set or empty, $HOME/.config/git/ignore is used instead. See gitignore[5].

act's .gitignore feature

• .gitignore file support:
  • .gitignore (per-directory) support: exists (by default, disable per --use-gitignore=false, compare Add option to allow files/directories in .gitignore to be copied to container #537)
  • .git/info/exclude support: exists (see Like Git does, act should also ignore the entries in git/info/exclude as well as the ones in ./.gitignore #1000)
  • core.excludesfile support: missing (this feature request Enhancement: core.excludesfile .gitignore (file) support #1160)
• git repo index support: exists (we may see it as unconfirmed/regression, compare Issue: actions/checkout doesn't copy git tracked but gitignored files #912)
• git-worktree(1) support: this is a different beast, see enable using worktrees #829

(report backstory: #1158)