Separation Anxiety - Making the Switch to Git LFS

If you're starting a new project, using Git LFS is easy. For existing projects, however, converting a project can present a few challenges. In this workshop, we'll adapt an existing sample project to use Git LFS with Git's filter-branch command as well as the BFG Repo Cleaner. We'll also talk about the implications of these approaches on your project and your collaborators. Attendees should have a general understanding of Git internals and be comfortable working on the command line.

Transcript

1. Separation Anxiety making the switch to Git LFS
2. Git Large File Storage
3. Working with large files has never been easier.
4. You have baggage.
5. Large Files Git LFS Baggage Git Internals Rewriting History The Future
6. Allen Smith GitHub @loranallensmith loranallensmith@github.com
7. The Problem
9. ! bigfile.psd (30M) " ! bigfile.psd (40M)
12. " # # $ % & ' # # ( & code code Local Remote file.psd file.psd Large File Storage
14. $ git lfs track <glob>
16. ! bigfile.psd (30M) " ! bigfile.psd (40M) ! bigfile.psd (35M) ! (
18. bigfile.psd $ git add <file> d747dc0 (blob) <content> <content>
19. $ git commit d747dc0 (blob) <content> cda316a (tree) 390303a (commit) bigfile.psd
21. " *
22. " * clean smudge
23. + .gitattributes
24. bigfile.psd $ git add <file> c9d083c (blob) <content> <pointer> d747dc0 (LFS object) <content>
25. * * .git objects
26. * * .git * lfs objects
27. This changes everything.
28. This changes everything. , - .
30. ! bigfile.psd (30M) " ! bigfile.psd (40M) ! bigfile.psd (35M) ! (
31. git filter-branch
32. This actually changes everything.
33. git filter-branch recreate commit history in a scriptable way /
34. Let’s plan it out.
35. Let’s plan it out. 0 1. Go back to the beginning of the project history, then for every single commit: 2. Tell Git LFS to track the right files 3. Stage the updated .gitattributes file 4. Get a list of all the paths that Git LFS should manage at this point 5. For each of those paths, stop tracking the non-LFS version of the file 6. Restage the file to have LFS create a pointer file for it 7. Don’t forget to update tags!
36. Let’s plan it out. 0 $  git  filter-­‐branch  -­‐-­‐prune-­‐empty  -­‐-­‐tree-­‐filter  '   git  lfs  track  "*.zip"   git  lfs  track  "*.exe"   git  add  .gitattributes   git  ls-­‐files  -­‐z  |  xargs  -­‐0  git  check-­‐attr  filter  |  \   grep  "filter:  lfs"  |  sed  -­‐E  "s/(.*):  filter:  lfs/\1/"  |  \   tr  "\n"  "\0"  |  while  read  -­‐r  -­‐d  $'"'\0'"'  file;  do          echo  "Processing  ${file}"          git  rm  -­‐f  -­‐-­‐cached  "${file}"          echo  "Adding  $file  lfs  style"          git  add  "${file}"   done   '  -­‐-­‐tag-­‐name-­‐filter  cat  -­‐-­‐  -­‐-­‐all credit: @vmrob
38. BFG Repo Cleaner an alternative to git-filter-branch focused on cleansing bad data from your repository. 1
39. How do I use it?
40. How do I use it? 0 1. Download  BGF  from  https://rtyley.github.io/bfg-­‐repo-­‐cleaner/   2. $  git  clone  -­‐-­‐mirror  <url>   3. $  cd  your-­‐repo.git   4. $  java  -­‐jar  bfg.jar  -­‐-­‐convert-­‐to-­‐lfs  ‘*.psd,  mp4,  <etc>’   5. $  git  reflog  expire  -­‐-­‐expire=now  -­‐-­‐all   6. $  git  gc  -­‐-­‐prune=now  -­‐-­‐aggressive   7. $  du  -­‐sh  *
41. rewriting history /
42. This actually changes everything.
44. rewriting history /
45. Other approaches
46. Git Large File Storage
47. Working with large files has never been easier.
48. Working with large files has never been easier. easy.