Essential Git for developers

With so many "Git how-tos" out there, where to start? This is not another one of those. Instead Adam Culp will give a practical walk through the development workflow cycle and how to use Git as the source control. From initialization of a repository, adding, staging, cloning, and checkout, we will walk through a sample project and how most developers actually use Git to manage the workflow.

Transcript

1. Essential Git For Developers By: Adam Culp Twitter: @adamculp https://joind.in/14744
2. 2 Essential Git For Developers • About me – PHP 5.3 Certified – Work at Zend Technologies – Organizer SoFloPHP (South Florida) – Organized SunshinePHP (Miami) – Long distance runner – Judo Black Belt Instructor
3. 3 Essential Git For Developers • Fan of iteration – Everything requires iteration to do well: (practice makes perfect) • Long distance running • Judo • Development • Avoid project managers • Version Control!
4. 4 Essential Git For Developers • Why use Git? – No centralization • No central server (unless desired) – Each clone = full repository • Git tracks state, history, and integrity – Branching and Merging work – Fast • Local vs Remote • Only one .git directory – Files to be committed are “staged” first – Free and Open Source – Flexible workflow
5. 5 Essential Git For Developers • How Others Looks At Data. – As files and the changes made to each file. Version 1 Version 2 Version 3 Version 4 Version 5 File A File B File C Diff 1 Diff 1 Diff 2 Diff 1 Diff 2 Diff 2 Diff 3
6. 6 Essential Git For Developers • How Git Looks At Data. – As whole files, not files + diffs. Version 1 Version 2 Version 3 Version 4 Version 5 File A File B File C File A1 File A2 File B1 File B2 File C1 File C2 File C3 File A1 File A2 File B File B File C2 Green means whole file, yellow means pointer to previous whole file.
7. 7 Essential Git For Developers • Subversion-Style Workflow Shared Repository Developer Developer Developer
8. 8 Essential Git For Developers • Integration Manager Workflow Blessed Repository Integration Manager Developer Public Developer Public Developer Private Developer Private
9. 9 Essential Git For Developers • Dictator and Lieutenants Workflow Blessed Repository Dictator Developer Developer Developer Developer Lieutenant Lieutenant
10. 10 Essential Git For Developers • Single Developer – One repository, everything in one basket. • Remember to backup Developer Local Repository
11. 11 Essential Git For Developers • Each 'git clone' == full repository
12. 12 Essential Git For Developers • What is actually going on? – A bunch of repositories! Repository Repository Repository Repository
13. 13 Essential Git For Developers • But it could be: – Repositories can connect in all directions. Repository Repository Repository Repository
14. 14 Essential Git For Developers • Most common commands – git config – git init – git clone – git status – git add – git commit – git log or show – git branch – git checkout – git merge – git pull or push
15. 15 Essential Git For Developers • Help! – Adding '-h' to any command will return help on usage.
16. 16 Essential Git For Developers • git config – Easily set your information to accompany commits. – Generally a one time thing.
17. 17 Essential Git For Developers • git init – Instruct Git to track project by simply 'git init'. – No more excuses! Version all the things!
18. 18 Essential Git For Developers • git clone {repo} {destination} – Creates new repository based on another. – Cloned repository becomes “Origin”. • Internal pointer for where it came from.
19. 19 Essential Git For Developers • Example of 'git clone' – Below we clone a repo from github. – We address the .git directory. – Specify where to put it.
20. 20 Essential Git For Developers • git status – Provides status of resources in the tracked project.
21. 21 Essential Git For Developers • git status – Below 'git status' informs us of untracked files after created.
22. 22 Essential Git For Developers • git add – Stages files to be committed.
23. 23 Essential Git For Developers • git commit – A 'git commit' includes all “staged” files. – Use '-m' to store a message with the commit. • Or git prompts user to add a message. (using default editor)
24. 24 Essential Git For Developers • More on commits – A commit should be: • Done OFTEN! • Commit messages – Always included – Short – Informative • Single commit per bug or ticket.
25. 25 Essential Git For Developers • git log – Shows history of prior commits. – We've only done one, and here it is:
26. 26 Essential Git For Developers • git show {commit hash} – Hash optional, will show previous by default. – Shows commit + diff view of files.
27. 27 Essential Git For Developers • What would a commit do? – We did a 'git add' for file #2, and modified file 1.
28. 28 Essential Git For Developers • And now? – We did a 'git add' for modified file 1.
29. 29 Essential Git For Developers • And finally? – We did a 'git add' for new file 3.
30. 30 Essential Git For Developers • After the commit. – All staged files were added. – A 'git status' reveals nothing new or different.
31. 31 Essential Git For Developers • Commits do not carry a version # – Git doesn't use numbers like 1, 2, 3... – Instead uses hashes like 6e7e6999c879f460b5e1d7e29ffe9907062ec20a
32. 32 Essential Git For Developers • Working in 'master' is bad. – Should not be working in the 'master' branch. – 'master' should be pristine version. • Most bug free. • Tested • Same as “Production”
33. 33 Essential Git For Developers • git branch – Shows a list of existing branches. – The * indicates active branch.
34. 34 Essential Git For Developers • git branch {name} {branch} • Or git checkout -b {name} {branch} – Creates new branch. – Checkout -b checks out after creation. – Below we create a 'development' branch. – New branch has same state as active/specified branch.
35. 35 Essential Git For Developers • git checkout {name} – Include “-b” flag to create new branch. – Switches to a specified branch. – Branches carry own state. – In file browser file contents different.
36. 36 Essential Git For Developers • What if? – A file has been edited, but not committed. – We are in 'development' branch. – What if we 'git checkout master'?
37. 37 Essential Git For Developers • Change branch with uncommitted files – Merges uncommitted content on checkout. • Whether 'staged' or not. – Does NOT merge over newly created files. (changes only) – Conflicts get exciting. (Not covered in this talk.)
38. 38 Essential Git For Developers • File not actually changed – On 'git checkout development' and commit: • File in development carries edit committed. • File in master is reset, even though merged previously. master development
39. 39 Essential Git For Developers • But if commit done first – Commit only done on active branch. – Master branch is unchanged. ('git log' shown below) – Master files do not contain merged changes. master development
40. 40 Essential Git For Developers • git merge {branch} – Git merges specified branch into active branch. – We merge change from development to master. • 'git checkout master' • 'git merge development'
41. 41 Essential Git For Developers • What are “fast forward” commits? – Merges individual commits into flow as if a checkout never occurred.
42. 42 Essential Git For Developers • Ignoring – We can exclude: • Files • Folders • Config files with passwords ! ! ! – Simply add excluded content to the file '.gitignore'.
43. 43 Essential Git For Developers • Typical branches for teams – Conventions: • Testing, Staging and Master branches off limits but public. • Development public, public to all. • {user}-development branches local and private.
44. 44 Essential Git For Developers • Typical rules for branch usage – No code leaves {user}-development unless finished and stable. • Developers merge to development branch...period! – Do NOT merge conflicts into any public branch.
45. 45 Essential Git For Developers • Commit procedure (origin pull/merge/push) – Before merging changes to public development: • 'git checkout development' • 'git pull origin development' – Should be no conflicts. • 'git checkout {user}-development' • 'git merge development' – Fix conflicts • 'git checkout development' • 'git merge {user}-development' • 'git push origin development'
46. 46 Essential Git For Developers • Public and Private branches – Typically {user}-development branches remain private. • The team is not aware of commits done there. • Frequent commits encouraged. – Development, Staging, and Master are public and entire team can view state/commits. • All developers can merge to development. • Only authorized people can merge to staging or master.
47. 47 Essential Git For Developers • Team Developer workflow – Git is ideal for team development
48. 48 Essential Git For Developers • Team Developer workflow (private) – Project/ticket assigned, create branch • 'git checkout development' • 'git branch {user}-development' or 'git checkout -b {user}-development' – Start coding. – Commit often. Checkout dev. to private {user}-development Project assigned
49. 49 Essential Git For Developers • Team Developer workflow (private) – Regularly commit code. • 'git add {filename}' X each file • 'git commit -m {commit message}' – Regularly pull from origin. • 'git checkout development' followed by 'git pull origin development' • 'git checkout {user}-development' followed by 'git merge development' Checkout dev. to private {user}-development Multiple commits Coding Project assigned
50. 50 Essential Git For Developers • Team Developer workflow (private) – Development completed, ready for QA testing. • 'git checkout development' • 'git pull origin development' should be no conflicts. • 'git merge {user}-development' should be no conflicts. Checkout dev. to private {user}-development Merge changes to development Multiple commits Coding Tests pass Project assigned
51. 51 Essential Git For Developers • Team QA workflow (public) – Testing done in development branch. – Failed developer picks up on {user}-development. → – Bug fixed re-push to development. → Testing from development Test passed Testing assigned no Return to developer flow
52. 52 Essential Git For Developers • Team QA workflow (public) – Testing done in development branch. – Success merge to staging → • 'git checkout staging' • 'git pull origin staging' • 'git merge development' • 'git push origin staging' Testing from development Merge to staging Test passed Testing assigned yes no Return to developer flow
53. 53 Essential Git For Developers • Team Deployment Mgr. workflow (public) – Regression testing done in staging branch. – Testing failed: • 'git branch -b {tempname}-staging' – Code to fix bug • 'git add {files}' • 'git commit -m {message}' Regression testing In staging Test passed Deploy assigned no Temp branch created
54. 54 Essential Git For Developers • Team Deployment Mgr. workflow (public) – Send fix back for regression testing done in staging branch. • 'git merge staging' just to check for conflicts. • 'git checkout staging' • 'git merge {tempname}-staging' Regression testing In staging Test passed Deploy assigned no Temp branch created Bug fixed
55. 55 Essential Git For Developers • Team Deployment Mgr. workflow (public) – If regression tests pass: • 'git merge master' in case of conflicts • 'git checkout master' then 'git pull origin master' • 'git merge staging' Regression testing In staging Merge to master Test passed Deploy assigned yes no Temp branch created Bug fixed
56. 56 Essential Git For Developers • Team Deployment Mgr. workflow (public) – All is good, create annotated tag. • 'git tag -a v1.0 -m '{message}' (Note: 'git tag' lists all tags.) Regression testing In staging Merge to master Test passed Deploy assigned yes no Temp branch created Bug fixed Tag created
57. 57 Essential Git For Developers • Single Developer workflow (small project) – Pretty similar, but no staging. – Note: Still use {user}-development per task/project/ticket. {user}-development Merge to development Test passed Project assigned Tag created Test passed Merge to master
58. 58 Essential Git For Developers • Tools – gitk – gitx – git-cola – SmartGit – GitEye – TortoiseGit – IDE • Eclipse – Zend Studio – Aptana • PHPStorm • etc.
59. 59 Essential Git For Developers • github.com – Great place to share code. – Promotes collaboration – API enhances connectivity and use – Awesome plugins – Easy to use
60. 60 Essential Git For Developers • github – how to clone locally – Standard 'git clone' command – Now have a clone local to work on. – Follow workflow as shown earlier.
61. 61 Essential Git For Developers • Conclusion – Always use source control!!! – Git is an easy solution, just 'git init'. – Plan a workflow and stick with it...ALWAYS! – 3rd party repositories = backed up – Git easy to connect to from anywhere. – Love iteration!
62. 62 Essential Git For Developers • Resources – http://nvie.com/posts/a-successful-git-branching-model/ – http://github.com – http://training.github.com/ – https://bitbucket.org/ – http://git-scm.com
63. Essential Git For Developers • Thank you! Adam Culp http://www.geekyboy.com http://RunGeekRadio.com Twitter @adamculp https://joind.in/14744 Questions?