Intro to Git & GitHub

This deck was used for Intro to Git & GitHub, a Girl Develop It Philly talk given October 12, 2013.

Transcript

1. Intro to Git & GitHub By Girl Develop It Philly <3
2. • Jana Beck • Sarah Gray • Sarah Johnson • Selah Lynch Your Instructors
3. Now it’s your turn . . . Introduce yourself :)
4. The Plan • Version Control as a General Concept • Git & GitHub Versus Other Version Control Systems • How to Use GitHub • Git -- The Basic Idiom • Git – Branches • Collaborating with Others -- Break -- • Setup GitHub Account • Setup Git on Your Computer • Lab Time • Wrap Up
5. Version Control as a General Concept
6. Why Use Version Control? • Made a change to code, realised it was a mistake and wanted to go back? • Lost code or had a backup that was too old? • Wanted to see the difference between two versions of your code? • Wanted to prove that a particular change broke or fixed some piece of code? • Wanted to experiment with a new feature without interfering with working code? http://stackoverflow.com/questions/1408450/why-should-i-use-version-control
7. When should I use it? • If you like the security of having your work backed up • If you work with documents that change a lot or have multiple versions • If you work on a team project • If you apply for engineering/developer positions
8. Git & Github Versus Other Version Control Systems
9. Version Control Version Control Software Distributed • Git • Mercurial • Bazaar Centralized • Subversion (SVN) • Concurrent Versions System (CVS) Remote Repository Hosting Services • GitHub • BitBucket • Your Own Server • Lots of other services!
10. Why are you learning git with GitHub? • Git is fast and full featured. • Github is *the* place for open source projects • http://whygitisbetterthanx.com/
11. With a Little Help from Ryan Gosling http://programmerryangosling.tumblr.com/
12. Some of the Criticism • Git is tooo haaarrrrd! ◦ Yeah, it doesn’t cut you any slack, but the tradeoff is that you get complete control • Everybody can see my stuff on GitHub. ◦ True, but you get to participate in a development community and are on your way to contributing to an open source project.
13. Why Command Line? • You will always have the full feature set available • You have a built in help function called the MAN page • If you are working with someone else, you won’t need to learn their client
14. A Quick Sidenote About Tools Used During the Lecture • I’ll be using sublime text to manage files ◦ http://www.sublimetext.com/2 • I’ll be using a bash terminal most of the time • I’ll show you ohmyzsh -- mac only :( ◦ https://github.com/robbyrussell/oh-my-zsh ◦ http://zsh-nt.sourceforge.net/ (windows?)
15. Basic Ideas for Git and Github • Local Repository ◦ where code is stored on your local machine • Remote Repository ◦ where code is stored by your hosting service
16. How to Use Github
17. Let’s Make a Remote Repo • Demo time! ◦ I am deliberately not providing instructions here because GitHub changes its interface all the time. My instructions would quickly become outdated. Google is your friend :)
18. A Quick Tour of GitHub • See repos • See commit stream • A quick aside: gists & github.io • Let’s make a repo!
19. Let’s Get That Same Repo on Our Local Machine • Your first git command! ◦ git clone <repo link from github>
20. Now What? Now that that we have a repo, let’s put some stuff in it.
21. Git -- The Basic Idiom
23. Why this order? • git pull ◦ let me see what others have done ◦ resolve merge conflicts early • git add <filename> ◦ let me bundle some work together • git commit -m “my comment” ◦ let me make a note about that bundle ◦ -m -- that’s a flag that says use no editor, use the string ◦ MAN page • git push ◦ send it up to the hosting service
24. The Editor http://programmerryangosling.tumblr.com/
25. local repo origin staging workspace
26. Other helpful commands • git status ◦ show me what’s happening right now • git log ◦ show me the local timeline • git log --pretty=oneline ◦ show me a simplified version of log
27. local repo origin staging workspace stash!!
28. The Stash • git stash save “note about what I am saving” ◦ My current work is not ready to be committed but I want to interact with the remote repo • git stash pop ◦ apply the last stashed change • git stash list ◦ show me all stashed changes
29. Humm, timeline, now that’s interesting. https://www.atlassian.com/git/workflows
30. Let’s Play with Reset and Work with the Timeline git log git reset <SHA/Commit ID from log>
31. When to commit • Often ◦ reduces the likelihood of merge conflicts ◦ makes it easier to have a fine-grained timeline to play with ◦ helps with good coding practice -- write a method, write some tests, commit
32. Sorry Ron . . . If you are writing a method that slices, dices, and sautees, you have a problem. Ditto if you have a commit with too much going on.
33. Let’s Violate my NDA JK -- I’m not sharing code, so no NDA violation.
34. Branches
35. What if I Want to Experiment? • Lets you work on an aspect of a project without disrupting the work of others. • Gives you an easy way to have two parallel streams of work until you are ready to settle on one solution. • Lets you mix-and-match features from each branch. • Branches are often used for development in a professional environment.
36. Master and Branch https://www.atlassian.com/git/workflows#!workflow-gitflow
37. Branch commands • What branch am I in? ◦ git branch • See local and remote branches ◦ git branch -a • Get a remote branch onto your local machine ◦ git checkout --track origin/<branch name> • Cut a new branch ◦ Make local branch ▪ git branch <branch name> ◦ Make remote branch ▪ git push -u origin <branch name> • Switch to a branch ◦ git checkout <branch name>
38. Merge If you want to merge all of your commits from branch to master: git checkout master git merge <branch name> It will interleave the commit history from branch with the commit history from master -- so it becomes a complete timeline!
39. Merge Conflicts https://www.atlassian.com/git/workflows
40. You’ll Need to Make Some Choices • Two Options: ◦ git mergetool ◦ use the editor • Commit the merged file
41. Let’s Violate my NDA, Again
42. Criticism • If I commit often and work on a branch. It’s harder to mix-and-match code ◦ git’s squash feature (git rebase -i <SHA/Commit ID from log>) lets you bundle commits together on branch, then you can git cherry-pick it to master http://stackoverflow.com/questions/5189560/how-can-i-squash-my-last-x-commits-together-using-git
43. Collaborating with Others
44. Two Ways to Do This: • Fork and Pull ◦ contributing to open source projects ◦ using code created by others ◦ http://xkcdgraphs.com/ • Shared Repo ◦ How a professional office would likely use git ◦ Git Workflow
45. Fork and Pull http://programmerryangosling.tumblr.com/
46. http://blogs.wandisco.com/2013/07/24/git-workflows-and-continuous-delivery-using-multisite-replication-to-facilitate-a- global-mainline/
47. The Difference Between Fork and Clone Fork & Pull/Fork & Clone -- a copy that exists in your GitHub account can be used submit pull requests/submit changes without a relationship to the project. Clone/ Shared Repo -- a copy that does not exist in your GitHub account and cannot change the remote repo unless the cloner is added as a collaborator on the project.
48. Git Workflow http://progit.org/book/ch5-1.html
49. Adding a Collaborator to Your Repo • Again, no instructions for GitHub’s website http://programmerryangosling.tumblr.com/
50. Break Time!
51. http://sarahelizgray.github.io/ Lab Time
52. Play Githug or Work on a Personal Project • Work on your own projects in git with instructor assistance • Discover advanced features by playing a game
53. Wrap Up
54. What’s Happened Today: • You know the difference between git and other VCS • You know about GitHub and other hosting services • You have git and GitHub ready to go! • You know the basic idiom • You know some advanced ideas like branches and git workflow • You know how to call the MAN page • You have a git cheat sheet
55. Spot the inaccuracy
56. Other Resources • Beautiful graphical representation of git features ◦ http://www.ndpsoftware.com/git-cheatsheet.html • Continue with Githug ◦ https://rubygems.org/gems/githug • A great in-depth guide to git, also a book ◦ http://git-scm.com/book • The original git and GitHub GDI class slides ◦ http://teach.github.com/presentations/git-foundations.html • More on git workflow ◦ https://www.atlassian.com/git/workflows#!workflow-gitflow • Student/Educator? -- you may need a private account ◦ https://github.com/edu • More silly Ryan Gosling programming jokes ◦ http://programmerryangosling.tumblr.com/
57. Don’t Forget to Evaluate the Course! This is the first time this course has been taught at GDI Philly. Your feedback is important! http://bit.ly/GRs1EC Thank you, Thank you, Thank you for coming!