The Great Git In The Sky

Every developer should know that having a good versioning system for your source files is crucial. Having the possibilities to go back in time and see what your class or module or project looked like is indispensible. And if you’re more than one developer on a project, having a common place – a repository – to store all files is even more indispensible.

Throughout the years I’ve tried a couple of different source control systems. Being a .Net developer on the Microsoft platform, I’ve tried both Visual SourceSafe (VSS) and Team Foundation Server (TFS) and I’ve also used the open source alternative SubVersion (SVN). Lately there’s a new source control system that has drawn my attention, namely Git.

Git is a fairly new source control system and was originally developed by Linus Torvalds to be used developing the Linux kernel. The first version of Git came in 2005, but wasn’t available on the Windows platform until late 2007 through the open source project msysgit (unless you were running the unix emulator cygwin, that is).

Git has a bit different take on how you manage source control than what I’ve been used to from the previous tools I’ve used. TFS, VSS and SVN lets you setup a centralized repository where you store all your files, keep track of version history, do branching, etc. But Git is a bit different in the sense that the repository is now localized on your machine and when several people are working on the same project, all repositories are essentially synchronized across all development machines – a so called distributed source control system. Which means that you have access to the full history of your source files locally. You can also have a remote Git-repository which local repositories can push and pull changes to and from, but all local histories still have the full version history.

Creating a Git repository using msysgit

For each project you want to put under source control, you just add a Git repository to the root folder of your project. Say you have some code laying on ‘C:\Code\Work\MyProject’. If you want to place this under Git’s source control and you’ve installed msysgit with the integration to Windows Explorer, then you just right click on the folder and choose ‘Git GUI Here’ (or ‘Git Bash Here’ if you’d rather use the command prompt). You have to choose ‘Create New Repository’ and then put in the directory ‘C:\Code\Work\MyProject’ in the textbox that follows (a little glitch in the UX design there; it would have been friendlier if it actually had remembered where I opened the GUI from and then put in that directory by default).

In the list of ‘Unstaged Changes’ in the upper right corner you can now choose the files you want to include in the repository. Select the appropriate files and then press Ctrl+T (Or Commit > Stage to commit). Then you can commit these into the repository with Ctrl+Return (Commit > Commit).

Alternatively you can do the same from the command line, and in fact there are a couple of things you should do on the command line before you start committing to the repository. First of all you should enter your name and email, as this will be used on all commits;

The ‘—global’ parameter hints that this is a configuration setting that will be effective across all Git repositories on this machine. You could also have done this through the Git GUI (Edit > Options…), but the next thing I’ll setup I couldn’t find a way to do in the current version (v 0.12.0.23); adding ignore patterns. In a typical .net project you wouldn’t want to add for instance the bin and obj folders to the repository, and the way to ignore these files is to add a ‘.gitignore’ file to the root folder of your project. You can try to do this in Windows Explorer, but I think you’ll quickly find that this is actually not possible. But through the bash it’s a walk in the park.

To make my point I’ve created a console app called GitExample and I’ve open the bash in the root directory. I can now issue a git init command that will initialize a Git repository here, and by calling git status I can list all files and folders that are currently not under source control:

And as we can see there are a lot of things here that I really don’t want to add to the repository. Let’s be ignorant;

The touch command will create the file and you can now edit it in your favorite text editor. The following list shows my ignorance;

With this in place we can now run the status command and we’ll see that there’s a lot less to care about for our Git commit process;

Now it’s time to add the files to the repository, which you off course can do either through the GUI or the command line, but since we’re already in Unix mode let’s do it the hard core way.

The procedure around committing files to the repository is 2-phased. We do a “add .” to add all untracked files in our working directory into the staging area of the repository. The staging area is set of files that are ready to be committed and you can do a lot of add (and remove) before you finally decide to commit all changes into the actual repository. And to commit the files you call the commit command with a “-m” parameter to add a comment to the files you’re committing. And as you can see from the screenshot above, after we’ve moved the files from the working directory to the staging area and then from the staging area to the repository, our working directory is now clean.

Mesh It Up!

I mentioned a bit earlier that if you want to share the repository with someone you can setup a remote repository. A popular repository host is GitHub which let you store up to 300mb free of charge (unlimited storage for public repositories). You can then push and pull changes to and from this location (take a look at this excellent blog post by Jason Meridth to see how you can do this).

Another alternative is to use your Live Mesh account as the remote repository. Pål Fossmo did a great blog on how you can setup Git together with Mesh which shows you how to configure your mesh folders. To initialize the Mesh repository you can use the clone command as shown below:

The clone command does what you think it does; it makes a copy of your repository and the bare parameter tells Git to strip down the repository to only what is necessary for the change tracking. That means no working copy of the source files – only the binaries, diffs, etc, that the Git database needs. You can then push and pull between local repositories and the Mesh repository which then will be synced with the cloud.

Why use Git?

“Git – the fast version control system”. I guess that the slogan will make a solid statement by itself, and if you’ve worked with source control systems before you’ll definitely appreciate the speed of Git. Visual SourceSafe is notoriously slow on just about every operation you perform (especially over http(s)). SubVersion is pretty fast on check-ins, but not that fast on check-outs. And TFS is pretty fast overall and also gives you the possibility to setup local proxies if you have distributed teams. But for a more quantified view on Git’s performance you can check out Scott Chacon which has compared the speed of Git to Mercurial and Bazaar.

TFS might compete to a certain extent on speed, but when it comes to the install footprint and not at least the effort it takes to actually install TFS 2008, Git will outperform TFS any day of the week. That said; TFS is a lot more than just a version control system. But if you plan on using TFS solely for the purpose of tracking your precious source files, my advice is pretty clear; Don’t! It’s not worth it – neither in time nor money.

Compared to SubVersion it strikes me that the merging capabilities of Git are a bit better. Git tracks the content of files – not the files itself, and so merging operations seams more likely to be correct in Git. In my opinion the merge operations in SVN is probably one of its weakest point; doing large merge operations in SVN is just pain and you just know you’re about to get burned. TFS on the other hand seems a bit better on the merging than SVN, but then again; time and money…

I guess it’s time for a little disclaimer here; I haven’t really used Git much yet, and so I haven’t done any large merge operations and so I might be wrong here. But from what I’ve read and from how Git is built as a distributed source control system, I have a strong feeling that merging is really one of Git’s sweat spots.

Anyways, if you have any other opinions on the subject – or to anything else in this post – please feel free to speak your mind in the comments below :)

Resources

“Git Manual Page” is the official documentation on Git and it’s actually quit good. Lot’s of good examples and pretty well written. RTFM, right?

“Everyday GIT With 20 Commands Or So” from the official tutorial will give you a head start on the most used commands.

“Git Ready” has put some of the commands into 3 categories; beginner, intermediate, and advanced.

“Git For Windows Developers” – the title says it all I guess.

“Git – SVN Crash Course” will give you a head start on using Git if you’re already familiar to SubVersion.

“Why Git is better than X” has done some (slightly biased?) comparisons against other source control systems.

msysgit is the tool to download and install if you need Git to run on a Windows box.

TortoiseGit is another client for Git repositories. If you’re familiar with TortoiseSVN for SubVersion, the learning curve will be close to zero.

GitHub lets you store up to 300mb in private repositories (unlimited storage for public repositories).

NDC 2009 Highlights

The Norwegian Developers Conference 2009 took place in Oslo last week and I was lucky enough to be one of the around 1000 attendees. That’s about half the crowd the organizer was hoping for, but I guess we’ll have to blame the ongoing financial turbulence for that. It was definitely not due to the speaker list, because that was straight out impressing. And the pricing seemed very reasonable too. Or maybe calling it the Norwegian Developers Conference scared away any foreigners? I don’t know, but those who weren’t there really missed out on a great event.

I’ll try to summarize some of my thoughts and impressions from this 3 day conference in this post, so let’s start with the most important part; the sessions. Most of the sessions was taped and will be available online in the (hopefully) near future. I had already studied the agenda in detail before I went, but as always when attending conferences like this; the plan was due to change. But I’ll try to list some of my favorite sessions from the conference and I really recommend taking a look at these when they come online. So here’s my top 5 in descending order;

1. Michael Feathers: “Working Effectively with the Legacy Code: Taming the Wild Code Base”

I’ve watched a couple of talks by Feathers up on InfoQ and he’s a really skilled speaker as well as writer. I haven’t had time to read his book “Working Effectively with the Legacy Code” yet, but it’s definitely one I will pick up soon. The talk was great and he had lots of good tips if you’re faced with a codebase that is not built to be testable.

2. Kevlin Henney: “The Uncertainty Principle”

On day 3 of NDC my original plan was to attend Scott Bellware’s whole day workshop on testing, but I was too late for the registration so the workshop filled up before I got to sign up. Instead I spend the whole day with Kevlin, which really was a great alternative. I was lucky enough to get to hear him doing a talk here in Trondheim about a month prior to the conference, so I knew that this was going to be good. Kevlin has done some great work on design patterns and his talks are both informative and entertaining. I really recommend all of his talks, but if I were to pick one favorite I’d go for “The uncertainty principle”.

3. Glenn Block: “Building Maintainable Enterprise Applications with Silverlight and WPF”

I’m a big fan of the PRISM and we’re using it on our current project. The talk was mainly about PRISM, but he also had some great tips on how to ease some of the pain in regards to databinding the ViewModel to the View. Now, don’t get me wrong here; I love databinding in WPF, but there’s some pain points regarding refactoring when it comes to the string-based databinding against properties in the ViewModel. Glenn showed off some interesting tools that he’s working on to make this easier, and it will be up on CodePlex in not so long (I hope!). The essence of the tool was that if you name your controls in the View the same as the corresponding property in the ViewModel, and then it could perform an auto-mapping between the View and ViewModel. Anyway; it was a great talk and I got some valuable tips to take with me. Unfortunately this was one of the none-taped sessions, so this will not be available online as far as I know.

4. Udi Dahan: “Designing High Performance, Persistent Domain Models”

Design patterns are in many ways lessons learned over the mere 50 years of developing software. PRISM is, among other things, a set of design patterns to apply if you’re building composite applications and is focused mainly on the presentation layer. Domain-driven design on the other hand are design patterns that focus on the core of the business; the domain model. Udi gave an excellent talk on the performance perspective of DDD.

5. Peter Provost: “Code First Analysis and Design with Visual Studio Team System 2010 Arch Ed Microsoft Visual”

It’s just amazing to see what the architect edition of VS10 contains and I really look forward to some of the features that Peter showed off here. He’s a joy to listen to and it just reeks knowledge of this guy. If you like a quick tour of VS10 architect edition and see how you can read code in a new dimension, I highly recommend this session.

Runners Up

Other memorable sessions to watch will be the .NET Rocks! episode recorded live [Update: Download the podcast here]. As always hosted by the Hardy & Hardy of the .Net community, Carl Franklin and Richard Campbell, and this time they had invited the HaaHa Brothers (Scott Hanselman and Phil Haack) to do a show. And what a show! Porn, beer and Bing – I say no more…

And the HaaHa Brothers show was also a blast. Haack showed some nice tricks to hack Hanselman’s “secure” bank application and the two of them just put together a great show. Put Hanselman on stage and you’re guaranteed a good time!

If you’re into DDD you’ll also find Jimmy Nilsson’s sessions quit interesting. Among other things he showed how one could use the upcoming Entity Framework 4 as the O/R-mapper in a DDD scenario. The way he turned user stories into BDD-ish unit tests was also quit interesting and definitely something I will try out myself.

The social side of it

Going to conferences like this is off course not only about the talks and the technical stuff. The social aspect of it is also a great part of it, and the NDC organizers had really put a lot of effort into making that part as equally successful as the technical side. The geek beer on Wednesday started off with an unforgettable jam session with Carl Franklin and Roy Osherove. Anyone who’s attended one of Roy’s talks knows that he has some amusing “alternative lyrics” on familiar songs. But what most people might not know is that Carl Franklin is a fantastic guitar player with an impressive voice. Where can we get your CD, Mr Franklin? Great gig! [UPDATE: Some guys from TypeMock recorded the jam session and they’ve published some clips here]

After a couple of beers we headed towards the city and some place to eat. Scott Hanselman’s got this ‘thing’ where he just got to dig up an Ethiopian restaurant in every city he visits. And so we joined Hanselman, Phil Haack, and some other guys for an exotic dinner at Mama Africa. Scott and Phil are just some incredibly nice guys and it was a memorable dinner – both the food and the company :)

The Big Party started with a decent dinner on Thursday evening. I mean; you really don’t expect much when you sit down with a cardboard plate filled with some sort of stew’ish dinner at a conference like this, but it really wasn’t that bad this time. And as the dinner had sunk in and the beer was starting to function, Datarock entered the stage. I must admit that electronica is not my favorite genre, but the performance that Datarock delivered was impressive. And how could you possibly go wrong with lyrics like this at NDC?

I ran into her on computer camp
(Was that in 84?)
Not sure
I had my commodore 64
Had to score

-- Datarock, Computer Camp Love

And after the Datarock concert we headed up to the geek bar. Loveshack had tuned in some never-dying 80ies classics that really got the geeks rocking. Great show!

Once again I was impressed that some of the speakers choose to hang out with us mere mortals. Phil Haack, Peter Provost, Scott Bellware, and Udi Dahan were all hanging around and took the time to socialize. Much appreciated!

A picture speaks more than the 1332 words on this page; NDC 2009 was just a big smile! Too bad it’s a whole year ‘till next time…

My NDC 2009 Agenda

The Norwegian Developer Conference 2009 will take place in Oslo from June 17th to 19th. I’ve been lucky enough to get my hands on a full 3-day ticket and I’m really looking forward to this event. I attended both TechEd Barcelona in 2007 and PDC last year in LA, but I can’t help thinking that NDC 2009 has got an even more impressive speaker lineup than both of those – at least if you’re in to agile practices and software craftsmanship.

If you’re thinking pure technology NDC might not be that impressive, but I personally believe that  the quality of a conference is a lot more about the quality of the speakers and how they present their thoughts and ideas, and less about the technological content. I’d rather spend an hour reading some good articles and try out some new technology hands on, than spending an hour on a bad chair in a room that always seem to lack oxygen listening to a mediocre speaker reading out loud every word on his/her powerpoint slides.

Going to conferences is about getting inspired. It’s about getting that tickling feeling of neurons going amok and new ideas swirl around in your head. It’s about triggering activity in your anterior superior temporal gyrus. And it’s all about the speakers. Skilled speakers with a lot of experience and confidence on stage giving a talk on a topic dear and near to their heart can really make a difference. And with a speaker lineup with names like Feathers, Rahien, Hanselman, Bolognese, Miller, Haack, Dahan, Osherove, Block, Provost, Bustamente, C. Martin, Lhotka… It’s just no way that this is going to be a mediocre event. It’s destined for success!

The worst part of this conference will actually be to pick which sessions to attend. It’s just impossible to not miss a great session, but hopefully they will all be videotaped and available online shortly after the conference. But the sessions are always best live, and one got to choose something. As it looks right now I believe this will be my agenda;

 

DAY 1
Ayende Rahien	Building Multi Tenant Apps	Haven’t had a chance to see Rahien live yet, but I’ve read and used some of his works
Michael Feathers	Working Effectively with the Legacy Code: Taming the Wild Code Base	I’ve seen some videos of Feathers up on InfoQ and I highly recommend his sessions
Juval Löwy	Productive Windows Communication Foundation	Don’t know much about Löwy to be honest, but getting productive with WCF is never bad.
Rockford Lhotka	Implementing Permission-based Authorization in a Role-based World	Got to have some technical sessions to, and though I’ve never used Rocky’s CSLA framework, I’ve listen to a couple of the DotNetRocks episodes he has attended. Besides; the content suits the project I’m currently working on perfectly :)
Udi Dahan	Intentions and Interfaces - Making Patterns Complete	Yet another one of those gurus you just read and hear a lot about.
Michael Feathers	Design Sense Deep Lessons in Software Design	Feathers again; he’s just that good.

 

DAY 2
Jeremy D. Miller	Convention over Configuration applied to .NET	Been following his blog for some time and I like his involvement with the Alt.Net community. Great interview with him on the Alt.Net podcast. And besides; CoC is facinating.
Roy Osherove	Unit Testing Best Practises	Went to Osherove’s sessions at TechEd in 2007 and it was well worth it. Hope he brings his guitar :)
Ted Neward	Extend the Customization Possibilities of your .NET App with Script	Ted is a great speaker and the scripting possibilities is something I’d really like to look more into.
Robert C. Martin	Clean Code: Functions	One of the most energetic speakers out there and Clean Code will be read in the upcoming weeks.
Rafal Lukawiecki	Architectual use of Business Intelligence in Application Design	BI has always been one of those fields that were interesting, but never had the time to really dig into. And from what I’ve heard Rafal was one of the top rated speakers at TechEd 2007 (or was it 2008?).
Jimmy Nilsson	Entity Framework + Domain-Driven Design = true?	I’ve read Nilsson’s book on DDD and seen his session at Øredev last year. I’m currently working on a project were we try to follow the guidelines of DDD, and so it will be interesting to see his take on EF + DDD.
Richard Campbell Carl Franklin	.NET Rocks! Live	I’ve followed the .NET Rocks podcast for quite some time and the live recordings are never dull. Will be interesting to see who they gather at their panel this time.

 

DAY 3
Scott Bellware	Full Day Tutorial: Good Test, Better Code	I’m a strong believer in TDD and Bellware is certainly one of the gurus in this field.

As you might have noticed from my list of speakers I try to spread my sessions to cover as many different as possible. That way I know which one I can spend time with when the videos come online.

And a little tip if you’re going to NDC (or any other conference); do not hesitate to leave a session that you find boring or uninteresting. It’s your time and you’d better spend it right!