Need to show a warning if Git LFS is used

[ZiroKyl]

Before submitting an issue, please be sure to

• [x] Read the contributing instructions
• [x] Update to the latest Gem version (run bundle update github-pages)

This issue affects

• [ ] The site generated by GitHub Pages
• [x] Building sites locally

What did you do (e.g., steps to reproduce)

1. jekyll new .
2. git init .
3. git lfs install
4. mkdir big-user-content && cd big-user-content
   1. git lfs track '*.png'
   2. git lfs track '*.jpg'
   3. git lfs track '*.gif'
   4. cd ..
5. add content...
6. bundle exec jekyll serve - testing site - Ok.
7. git add .
8. git commit -m "Hello world"
9. bundle exec jekyll serve - testing site, again - Ok.
10. git remote add origin https://github.com/:user/:repo.git
11. git push --all -u origin
12. open https://:user.github.io/:repo/ site -> Woops, where is my images?
13. googling:
    • git-lfs/git-lfs#791
    • git-lfs/git-lfs#1342
14. recreate the repo...

What did you expect to happen?

1. jekyll new .
2. git init .
3. git lfs install
4. mkdir big-user-content && cd big-user-content
   1. git lfs track '*.png'
   2. git lfs track '*.jpg'
   3. git lfs track '*.gif'
   4. cd ..
5. add content...
6. bundle exec jekyll serve - testing site - Warning!.

What happened instead?

See "steps to reproduce".

Solutions

• [fast] check if .git/lfs directory is exist and not empty
• [proper] parse git lfs track and git lfs ls-files output

[parkr]

Great idea! A little class/method to check this would be neat and help reduce confusion.

def contains_lfs_files?(site_source)
  return unless File.exist?(File.join(site_source, ".git", "lfs"))
  lfs_files = `git lfs ls-files HEAD`.strip
  return if lfs_files.empty?
  Jekyll.logger.warn "GitHub Pages:", "We detected some Git LFS files on your current ref. Git LFS is not supported by GitHub Pages, so these files will not show up on your GitHub Pages site."
end

[ZiroKyl]

If I understand this code correctly.

The code failure if:

• user set own lfs.storage (user have different repositories sharing the same storage directory?):
  • https://github.com/git-lfs/git-lfs/blob/739128a3fd9c7d95c96c4377f847a47596ee2c25/fs/fs.go#L24-L25
  • https://github.com/git-lfs/git-lfs/blob/v2.3.4/docs/man/git-lfs-config.5.ronn#L65-L73
  • git lfs env (see LocalMediaDir and TempDir)
• git-lfs is not installed. git lfs ls-files HEAD output git: 'lfs' is not a git command. See 'git --help'. (output is not empty)

The code show warning only in step 9:

1. jekyll new .
2. git init .
3. git lfs install
4. mkdir big-user-content && cd big-user-content
   1. git lfs track '*.png'
   2. git lfs track '*.jpg'
   3. git lfs track '*.gif'
   4. cd ..
5. add content...
6. bundle exec jekyll serve - testing site - Ok.
7. git add .
8. git commit -m "Hello world"
9. bundle exec jekyll serve - testing site, again - Warning!.
10. ~~git commit --amend --no-edit~~ recreate the repo...

Solution: add additional check for git lfs track output.

[ZiroKyl]

The code failure if:

• git-lfs is not installed. git lfs ls-files HEAD output git: 'lfs' is not a git command. See 'git --help'. (output is not empty)

Example:

• PC0 - git-lfs installed
• PC1 - git-lfs not installed

PC0

1. jekyll new a && cd a
2. git init .
3. add content...
4. ...something run git lfs env (this will create .git/lfs/*)
5. tar -C ../ -czf ../a.tar.gz a
6. bundle exec jekyll serve - testing site - Ok.

PC1

1. tar -xzf a.tar.gz && cd a
2. bundle exec jekyll serve - testing site - We detected some Git LFS files on your current... :open_mouth:

[alanxoc3]

bump. This should be a thing. I was confused about why my website didn't load images. Also, is there a reason why pages can't support git-lfs?