EBC Exercise 16 git

From eLinux.org
Revision as of 00:01, 18 January 2012 by Yoder (Talk | contribs) (0. Set Up Git: Updated formatting)

Jump to: navigation, search


git is a distributed revision control system with an emphasis on being fast. It was initially designed and developed by Linus Torvalds for Linux kernel development. The purpose of this lab is to get hands on experience with git to learn how it works and how to use it.

Much of the material here has come from Pro Git. We'll be using github to practice gitting.

0. Set Up Git

Go to github and follow the directions for installing and setting up git. No need to set up your own repository right now (unless you want to), I already have one set up for you the play with.

I suggest you do this for both your host computer and your Beagle. On the Beagle use

beagle$ opkg update
beagle$ opkg install git
beagle$ opkg install openssh-keygen

The last opkg installs ssh-keygen which is needed to work with github.

On my host computer I had to run

host$ ssh-add id_rsa

after running ssh-keygen to get ssh -T git@github.com to work.

1. Play with git locally

Pro Git has a nice on-line book with lots of good details. I'll lead you through many parts of it. The first chapter is Getting Started. Here are the topics:

1.1 - About Version Control
1.2 - A Short History of Git
1.3 - Git Basics
1.4 - Installing Git
1.5 - First-Time Git Setup
1.6 - Getting Help
1.7 - Summary

I'll cover Git Basics in class and you have already done parts 1.5 and 1.6 to set up for github. I suggest you take a look at Getting Help and then move on.

2. Git Basics

Chapter is on Git Basics. The topics are:

2.1 - Getting a Git Repository
2.2 - Recording Changes to the Repository
2.3 - Viewing the Commit History
2.4 - Undoing Things
2.5 - Working with Remotes
2.6 - Tagging
2.7 - Tips and Tricks
2.8 - Summary

There is lots of good material here. I suggest you work through it all. Section 2.1 shows how to clone a remote repository. Try using my repository.

git clone git@github.com:MarkAYoder/gitLearn.git

gitk looks like a nice tool. Be sure to take a look at it.

Questions you should be able to answer after doing chapter 2

  1. How do you stage a file?
  2. How do you view staged and unstaged changes?
  3. How do you view comment history?
  4. You've just committed something and realize you meant to have committed one more file. How do you add that file to the commit you just did?
  5. How do you unstage a file?
  6. How do you unmodify a file?
  7. After running the remote -v how do you tell if a site is read only or read/write?
  8. What's the difference between a lightweight and an annotated tag?

3. Git Branching

Chapter 3 is on branching. Here's the topics from the book:

3.1 - What a Branch Is
3.2 - Basic Branching and Merging
3.3 - Branch Management
3.4 - Branching Workflows
3.5 - Remote Branches
3.6 - Rebasing
3.7 - Summary

I'll work through 3.1 in class. Read through 3.2 and then do the following exercise.

Merging helloBeagle.c

  • clone my repository (The pass phrase is Hiapp)
$ git clone git@github.com:MarkAYoder/gitLearn.git
$ cd gitLearn
  • Edit helloBeagle.c and add a printf with your name on it.
  • stage and commit helloBeagle.c. You may have to merge. Keep everyone else's name in the file.
  • Push it to the repository.

Once everyone has done this we should have a file with everyone's name in it.

Moving from svn

Here's a nice article on a common git workflow for those who are moving from svn.

Extra Notes

The following are extra notes I may clean up later.

Access ti/staging

Here is what I did to access the ti/staging stuff.

host $ cd ~/oe/openembedded
host $ git remote add gitor git://gitorious.org/angstrom/openembedded.git
host $ git fetch gitor
host $ git checkout gitor/ti/staging -b ti/staging
host $ cd ${OETREE}
host $ wget http://download.berlios.de/bitbake/bitbake-1.8.18.tar.gz
host $ tar -xvf bitbake-1.8.18.tar.g
host $ gedit source-me.txt

Change

PATH=${OETREE}/openembedded/bitbake/bin:${ORG_PATH}

to

PATH=${OETREE}/bitbake-1.8.18/bin:${ORG_PATH}

Save and quit gedit

host $ . source-me.txt
host $ cd ~/oe
host $ mv angstrom-dev angstrom-dev.v0
host $ bitbake console-image