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3.1.2 Version control
Application setup
It is wise during development to use version control software to provide checkpoints
in your code. When the code is working, you can make a commit, and if anything goes
wrong later in development, you can revert to the commit. Additionally, you can create
branches for experimental features and work on those independently of the main
code base without damaging working code.
This book doesn’t go into detail on how to use a version control system, but it does
recommend using Git. Git is a distributed version control system that is easy to use and
extremely powerful. If you wish to learn about Git, we recommend reading Pro Git, a
free online book by Scott Chacon. 2
Git is used by most developers in the Rails community and by tools such as Bundler,
discussed shortly. Learning Git along with Rails is advantageous when you come
across a gem or plugin that you have to install using Git. Because most of the Rails
community uses Git, you can find a lot of information about how to use it with Rails
(even in this book!) should you ever get stuck.
If you do not have Git already installed, GitHub’s help site offers installation guides
for Mac, 3 Linux, 4 and Windows. 5 The precompiled installer should work well for Macs,
and the package distributed versions (APT, eMerge, and so on) work well for Linux
machines. For Windows, the msysGit application does just fine.
For an online place to put your Git repository, we recommend GitHub, 6 which offers
free accounts. If you set up an account now, you can upload your code to GitHub as you
progress, ensuring that you don’t lose it if anything were to happen to your computer.
To get started with GitHub, you first need to generate a secure shell (SSH) key, which
is used to authenticate you with GitHub when you do a git push to GitHub’s servers. 7
Once you generate the key, copy the public key’s content (usually found at ~/.ssh/
id_rsa.pub) into the SSH Public Key field on the Signup page or, if you’ve already signed
up, click the Account Settings link (see figure 3.1) in the menu at the top, select SSH
Public Keys, and then click Add Another Public Key to enter it there (see figure 3.2).
Figure 3.1 Click Account Settings.
2 http://progit.org/book/.
3 http://help.github.com/mac-set-up-git/. Note this lists four separate ways, not four separate steps, to install Git.
4 http://help.github.com/linux-set-up-git/.
5 http://help.github.com/win-set-up-git/.
6 http://github.com.
7 A guide for this process can be found at http://help.github.com/linux-key-setup/.
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