Up to speed with Git

Short Git introduction followed up by few Git exercises.

Introduction will teach you what Git is, how does it compare to other version control systems and how Git helps you when you’re developing software with agile methods.

The exercises with Git help you in learning what’s in it for you.

After going through this presentation and the exercises you’ll be able to go full throttle with Git and get your colleagues (and bosses) convinced of the benefits of Git.

Transcript

1. Up to speed with Git Some talk and some hands-on stuff as well Your host tonight: Kimmo Toro kto@iki.fi This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
2. GIT INTRODUCTION
3. What is Git?
4. It’s free
5. It’s fast
6. It’s effective
7. It’s redundant
8. It’s dumb
9. It’s not evolution of Subversion
10. It’s not complicated
11. It’s not panacea
12. It’s Distributed
13. Every Git clone is a full-fledged repository
14. You can do a lot of things offline
15. Perform a diff, view history of any file, commit changes, merge branches, obtain any version of any file, create and switch branches, stash changes, create new repositories...
16. Offline = local = fast
17. You can sync with any of the clones
18. You can use almost any workflow you want
19. You have plenty of backups
20. Git tracks content
21. Snapshots, not patches
22. Git makes branching easy
23. Branching becomes an everyday operation
24. Merging branches is easy
25. Branching and merging are both local operations
26. This is COOL, you know why?
27. Try out ideas Alternative fixes Isolate work units
28. 1. Get latest version of the codebase 2. Create a branch for fixing bug #128 3. Work for an hour 4. EMERGENCY! Quick, we need a hotfix for bug #256!!! 5. Checkout master branch 6. Create a branch for bug #256 7. Fix #256 8. Checkout master branch 9. Merge branch for bug #256 10. Push changes to central repo 11. Checkout branch for bug #128 and continue working
29. Which of those operations required network connection?
30. 1. Get latest version of the codebase 2. Create a branch for fixing bug #128 3. Work for an hour 4. EMERGENCY! Quick, we need a hotfix for bug #256!!! 5. Checkout master branch 6. Create a branch for bug #256 7. Fix #256 8. Checkout master branch 9. Merge branch for bug #256 10. Push changes to central repo 11. Checkout branch for bug #128 and continue working
31. 1. Get latest version of the codebase 2. Create a branch for fixing bug #128 3. Work for an hour 4. EMERGENCY! Quick, we need a hotfix for bug #256!!! 5. Checkout master branch 6. Create a branch for bug #256 7. Fix #256 8. Checkout master branch 9. Merge branch for bug #256 10. Push changes to central repo 11. Checkout branch for bug #128 and continue working Remote operation Remote operation
32. Git Basics
33. Initialize a new repository git init
34. Clone a remote repository git clone
35. Add files git add
36. See status git status
37. Commit git commit
38. See log git log
39. Publish changes git push
40. Get others’ changes git pull
41. Pay attention!
42. Local workflow Working directory Index Repository git add git commit
43. Local workflow Working directory Index (Local) Repository git add STAGING git commit Stuff here is staged Sandbox / work in progress Committed stuff goes here
44. Local workflow Working directory Index (Local) Repository git add STAGING git commit Stuff here is staged Sandbox / work in progress Committed stuff goes here git status shows status of working directory and stuff in index git log shows what has already been committed
45. Pay even more attention!
46. After you have made changes, you need to stage your changes git add
47. GIT IN PRACTICE
48. Git Installation http://git-scm.com/
49. Git Configuration git config --global user.name "John Doe" git config --global user.email “jd@m.com" git config --global color.ui auto
50. First Exercise 1. Create a repository 2. Add two files in it 3. Check status 4. Commit 5. Check status 6. Check log
51. Second Exercise 1. Modify something 2. See status
52. Second Exercise 3. Try to commit 4. What went wrong?
53. Second Exercise 5. Add changes to index 6. See status 7. Now commit
54. Precious tip #1 You can change your last (unpublished) commit with git commit --amend
55. Third Exercise 1. Again, do some modifications 2. Add modified stuff to index 3. See status - don’t commit yet! 4. Modify same file(s) again 5. See status 6. Commit
56. Fourth Exercise Explain, what just happened?
57. Local workflow Working directory Index (Local) Repository git add STAGING git commit Stuff here is staged Sandbox / work in progress Committed stuff goes here git status shows status of working directory and stuff in index git log shows what has already been committed
58. Git Takes Snapshots When you stage something, Git takes a snapshot and stores it to the index.
59. Exercise number five Investigate different options for git log
60. Precious Tip #2 You can store your favorite git commands as handy aliases Windows: git config --global alias.lg "log --pretty=format:'%%h - %%an, %%ar : %%s'“ Linux: git config --add --global alias.lg "log --pretty=format:'%h - %an, %ar : %s'"
61. Exercise #6 1. Launch gitk 2. Do some work on your git repository (modify, add, commit etc.) 3. Hit F5 after changes to refresh gitk UI 4. Try to understand what it is showing to you
62. #7 Branching 1. Create a new branch and switch to that 2. Add some new files and commit them in the branch 3. Check gitk once and a while
63. #7 Branching 4. Switch back to master branch 5. Where are your new files now? Explain.
64. Merging (that’ll be #8) 1. Merge your previously created branch to master 2. What happened? 3. What does gitk show? 4. What does git log show? 5. Delete unneeded branch
65. Stashing (Nine) 1. Do some changes (where ever) 2. Stash your changes aside 3. Do some other changes, commit 4. Get your stashed changes back
66. Rebasing (ten already?) 1. Create yet another branch, switch to it 2. Do some changes, commit 3. Switch to master, do some changes, commit 4. See gitk
67. Rebasing (#10) 5. Merge changes from the branch to master 6. What happened? 7. What does gitk show? 8. What does git log show? 9. Again, delete unneeded branch
68. Still Rebasing (X) 10.Create a branch, switch to it 11.Do changes, commit 12.Switch to master, do changes, commit 13.Checkout branch 14.Rebase master to branch
69. Rebasing ‘til it hurts 15.Check what gitk shows 16.See git log 17.Checkout master and merge your branch there 18.See gitk and git log
70. Merge vs. Rebase A B C E D F G H topic master
71. Merge A B C E D F G H topic master Merge C + H I As a result we have a new commit (I) which has two parents (C and H)
72. Rebase A B C E D F G H topic master
73. Temporary hideout Rebase 1 A B C E D F G H topic master
74. Temporary hideout Rebase 2 B C D E D F G H topic master F G H
75. Rebase 3 A’ B’ C’ E D F G H topic master F G H As a result we have new commits(F-H) from master now in our topic branch
76. Merge after Rebase A’ B’ C’ E D F G H topic master F G H As a result Git actually just moves the pointer for master to point to last commit in topic. There are no additional commits made. A’ B’ C’
77. More stuff (and no time) • Cloning a repository • Pull vs. Fetch and Merge • Pushing changes upstream • Creating and tracking remote branches • Interactive rebasing • Git reset
78. THANK YOU That’s all for now