Gotta get GitChris Sherwood and Alfredo Aretxabaleta

USGS Woods Hole

Git documentation

• Git - - distributed-is-the-new-centralizedhttp://git-scm.com/doc

• Git for SVN usershttp://git-scm.com/course/svn.html

• “Pro Git” – Scott Chacon (also online)• “Pragmatic Guide to Git” – Travis Swicegood• CRS attempts

http://csherwood.tiddlyspot.com/

Advantages

• Designed for distributed development– All local repos are complete– Anybody can make a local archive– You can pull from any archive you have access to

• Most operations are local (faster, work offline)• Integrity: everything is check-summed• Only adds data (maybe safer)• Lightweight, local branches• GUI tools and hosting services similar SVN

Disadvantages

• A(nother) learning curve• Sometimes TM(U)I

• Also, sometimes too much typing

Installation

• Linux, Cygwin often have git, but if not:$ sudo apt-get install git-core

• Mac can get it via MacPorts$ sudo port install git-core +svn +doc +bash_completion +gitweb

• Windowshttp://code.google.com/p/msysgit

Modified after “Pro Git”

First-time user setup

Important$ git config --global user.name “csherwood (ubuntu)“$ git config --global user.email csherwood@usgs.gov

Optional$ git config --global core.editor xemacs$ git config --global merge.tool meld

Check settings$ git config --list Modified after “Pro Git”

Centralized Repository

From “Pro Git”

Distributed Repositories

From “Pro Git”

ROMS and CSTMS SVN

CSTMS trunk

crs branch

dev3 branch

dev2 branch

ROMS trunk

crs branchworking copy

crs trunkworking copy

Hernan trunkworking copy

svn copy

svn checkoutsvn updatesvn commit

svn checkoutsvn updatesvn commit

svn checkoutsvn update

?

? ?

COAWST GIT

crs origin/master

COAWST origin/master

crsmaster

sed branchtrack kumar branch

Warnermaster

track kumar branchtrack crs branch

...

git fetchgit pullgit push

git clone

kumar origin/master

kumarmaster

wec branch

git pullgit push

git pullgit pushgit fetch

git fetch

Branch Development

waves

seds

Modified after “Pro Git”

Arrows point back to snapshots

First attempt

• Check out copy COAWST from SVN• Export from SVN to gcoawst• In gcoawst

git initgit add *git commit

• Make a bare repository (no working dir)git clone --bare gcoawst gcoawst.gitscp –r gcoawst.git csherwood@peach.whoi.edu:/peach/data2/csherwood/src/gcoawst.git

First attempt, second page

• crs cloned it• ala cloned it• ala made a branch and switched to it• ala added the new sediment stuff to the branch and

committed it• crs made a branch that tracked ala’s repo• crs fetched ala’s changes• crs merged them into his master• crs pushed them up to the repository• new users can clone/pull new sediment stuff from the

repository

A few things we could not have done with SVN

• Made our own shared repository based on the source repo (without admin)

• Merged Alfredo’s branch into my branch without going to a repo

• Its faster…• …but confusing

If we wanted to try it…

• Pick a stopping point…maybe make a tagged SVN release

• Use the tools to port the SVN history to git• Let John work on it for a while, allowing

people to clone it• Pick a project to track, and work out the

protocol for tracking branches• Hey, if Linus Torvalds can do it….