#Source Code Management

Why use version control

Version control records changes that are made so you can recall specific version later
Makes it possible for you to work on a feature/bug fix/release without changing production code
No more "file-version3.py" or "config-020315.conf"!
Since everything is pure text it's easy to "merge" new code into existing

Git

A distributed version control system, where every user has a complete and full copy of the source code.

If you can't check it in, you can't keep track of it, so you can't version it, so you can't automate it.

Everything belongs in source code control, and git is the standard in 3rd platform.

Other possible options: subversion (svn), mercurial (hg), Perforce (p4), ClearCase (cc).

#GitHub

A freemium service to host Git repositories (repos). Public repos are free, private ones are still cheap.

Most open source projects are hosted and collaborated on here.

If you're not on GitHub you don't exist. -- Friendly developer

#Using Git

(you have git installed, right? It was in the prework!)

#Clone A Repo

git clone https://github.com/rickscherer/training-repo.git

Now, explore that repo folder:

#Make A Change

Edit a file in notepad or textedit. Save it.

Back in the CLI, run: git status

#Add To Repo git add .

#Commit That Change

git commit -a -m "My Changes Are Awesome"

#Revert that commit

git reset --soft HEAD~

#Cool!

#Infrastructure As Code

##Imagine If:

Your switches could be updated like that?
Servers could be deployed like that?
You didn't write 'as built' documentation, because your code was documentation?

#Real World

#KCG: What Happened

#$440 million loss... #in 45 minutes