Git, GitHub, Etc

How git and GitHub work, behind the scenes. Aka what I do in my day job.

Transcript

1. Git, GitHub, Etc Andy Delcambre
4. PLANET ARGON
9. DIRECTED ACYCLIC GRAPH
10. yt $ git init Initialized empty Git repository in /private/tmp/demo/.git/ yt $ echo "My sweet repo" > README yt ✗ $ git add README yt ✗ $ git status # On branch master # # Initial commit # # Changes to be committed: # (use "git rm --cached <file>..." to unstage) # # new file: README # yt ✗ $ git commit -m "Add a README" [master (root-commit) 8a720fa] Add a README 1 file changed, 1 insertion(+) create mode 100644 README yt $ git log commit 8a720fa06710948f2ab79dd3e213ef745b6000c5 Author: Andy Delcambre <andy@github.com> Date: Mon Apr 14 15:41:34 2014 -0700 ! Add a README
11. 8a720fa HEAD, master Refs Commit
12. yt $ echo "It's so awesome" >> README yt ✗ $ git add README yt ✗ $ git commit -m "Update README" [master ede0fc8] Update README 1 file changed, 1 insertion(+) yt $ git log --graph --decorate --pretty=oneline * ede0fc8 (HEAD, master) Update README * 8a720fa Add a README%
13. Commit 8a720fa ede0fc8 HEAD, master Refs Commit
14. yt $ git cat-file -p ede0fc8 tree 493fc85c806ebd9e49395561d2f9c98a5d9ebdce parent 8a720fa06710948f2ab79dd3e213ef745b6000c5 author Andy Delcambre <andy@github.com> 1397516385 -0700 committer Andy Delcambre <andy@github.com> 1397516385 -0700 ! Update README
15. Commit ede0fc8 8a720fa 493fc85 Parent Tree
16. yt $ git cat-file -p 493fc85 100644 blob 17ca828132ebdc5347f4c5c20484b9a33fffb294 README !
17. Tree 493fc85 17ca828 Blob (README)
18. yt $ git cat-file -p 17ca828 My sweet repo It's so awesome
19. GitHub
20. Secret:
21. Hosting a Git repo is Secret:
22. Hosting a Git repo is Secret: EASY
23. enzo $ git init --bare demo.git Initialized empty Git repo in /home/adelcambre/git/demo.git/ ! yt $ git remote add origin adelcambre@enzo:git/demo.git yt $ git push origin master Counting objects: 6, done. Delta compression using up to 8 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (6/6), 473 bytes, done. Total 6 (delta 0), reused 6 (delta 0) To adelcambre@enzo:git/demo.git * [new branch] master -> master ! yt $ git clone adelcambre@enzo:git/demo.git Cloning into 'demo'... remote: Counting objects: 6, done. remote: Compressing objects: 100% (2/2), done. remote: Total 6 (delta 0), reused 0 (delta 0) Receiving objects: 100% (6/6), done.
25. yt $ git remote add -f origin git@github.com:adelcambre/demo.git Updating origin From github.com:adelcambre/demo * [new branch] master -> origin/master ! yt $ git push origin master Counting objects: 6, done. Delta compression using up to 8 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (6/6), 473 bytes, done. Total 6 (delta 0), reused 6 (delta 0) To https://github.com/adelcambre/demo.git * [new branch] master -> master
28. GitHub Flow
29. Make a branch
30. Add Commits
31. Open a Pull Request
32. Discuss & Code Review
33. Merge and deploy
35. Not so Secret:
36. Hosting a *lot* of Git repos is Not so Secret:
37. Hosting a *lot* of Git repos is Not so Secret: HARD
38. > 7 million repositories
39. 1.5 million pushes
40. 100 million pulls & clones
41. 27 fileservers
42. 100 TB of online storage
44. Grit
45. 1st Commit GitHub
46. 1st Commit GitHub 1st Commit Grit
47. Ruby wrapper around Git
48. repo = Grit::Repo.new(“grit.git”) ! repo.commits # => [#<Grit::Commit "e80bbd2ce67651aa18e57fb0b43618ad4baf7750">, #<Grit::Commit "91169e1f5fa4de2eaea3f176461f5dc784796769">, #<Grit::Commit "038af8c329ef7c1bae4568b98bd5c58510465493">, #<Grit::Commit "40d3057d09a7a4d61059bca9dca5ae698de58cbe">, #<Grit::Commit "4ea50f4754937bf19461af58ce3b3d24c77311d9">]
49. This works for everything! ! (locally)
50. 27 fileservers
51. Smoke “Grit in the cloud”
52. The Internet Chimney fs102 fs103 fs104 fs105 … fe102 fe103 fe104 fe105 …
53. The Internet Chimney fs102 fs103 fs104 fs105 … fe102 fe103 fe104 fe105 …
54. The Internet Chimney fs102 fs103 fs104 fs105 … fe102 fe103 fe104 fe105 …
55. The Internet Chimney fs102 fs103 fs104 fs105 … fe102 fe103 fe104 fe105 …
56. The Internet Chimney fs102 fs103 fs104 fs105 … fe102 fe103 fe104 fe105 … BERTRPC
57. module Smoke def self.install! ::Grit.send(:remove_const, :Git) ! ::Grit.const_set(:Git, Smoke::Git) end end
58. repo.ls_tree("HEAD").each do | entry| if entry.blob? repo.load_blob(entry.oid) end end
59. Death by Round Trip
60. A condensed (and probably wrong) history of git
61. Bitkeeper
62. Git
63. Shared library?
64. libgit2
65. JGit
66. libgit2 http://github.com/libgit2/libgit2
67. Rugged http://github.com/libgit2/rugged
68. Ruby wrapper around libgit2
69. repo = Rugged::Repository.new("rugged.git") ! repo.last_commit # => #<Rugged::Commit:2227356240 oid: 0277b7df0fea08d5f3fc7177e47527fc24d96a0e>
71. GitRPC The New Hotness aka
72. Like Smoke, But Better
73. Caching
74. Pluggable Wire Protocols
75. Encoding Aware
76. This is My Job
77. education.github.com
78. Questions! Git for Computer Scientists http://eagain.net/articles/git-for-computer-scientists/ My mom told me git doesn’t scale https://vimeo.com/64716825 GitHub Flow https://guides.github.com/introduction/flow/index.html How GitHub uses GitHub to build Github http://zachholman.com/talk/how-github-uses-github-to-build-github/