I have been using Git for years now and I am still a novice user. Actually, if you are an individual developer or work in a really small team, you don’t really need to go beyond using the basic stuff like cloning a repo, committing code, branching and pushing back to the origin repo. And that’s exactly what happened with me. Working alone most of the times and working in my own repos. I never felt the need to explore advanced usage.

Last week, we didn’t have internet at home for like four days. So, I thought I’ll read a book. I downloaded ProGit : The Free Git Book and started reading. It’s an awesomely written book. I learned a lot of new things about Git. A few more concept about using branches efficiently. If you are a Git beginner or looking forward to getting started with Git and you don’t like reading too much, I’ll suggest that you read at least first three chapters thoroughly. That along with a free GitHub account should be enough to get you going if you are not going to be a heavy Git user soon.

Fedora Tutorials by Kulbir Saini.

Summer has already started and we (a small group of current and ex-IIITians in Hyderabad) are planning to have some fun digging into Ruby on Rails and related technologies. If you are also interested in utilizing your summer in a productive and fun way, you can join us and share your knowledge while learning from the rest of the members at the same time.

Assuming that all of us know at least one programming language (C/C++/Python), below is the list of things we are planning to learn.

1. Ruby
• If you already know a programming language, it’ll not be difficult for you to pick up Ruby.
• In case you happen to know Python, you’ll feel at home.
• Spend a good half an hour on Ruby In Twenty Minutes and you’ll know how simple and beautiful Ruby is.
• Once you are done with Ruby quick-starter, you can try ruby in your browser and have some fun.
• Please go through Ruby Style Guide to see how to write beautiful and easy to understand Ruby code.
2. Rails
• If you have worked with any MVC framework in past, you’ll pickup rails quite easily.
• If you have worked with Web2py, then go through this Rails vc Web2py presentation which tries to show similarities among both frameworks.
• RailsGuides is one of best and complete documentation for getting started with Ruby on Rails. It may look like a lot of content to beginners. If that’s the case with you, you can skip the guides in Digging Deeper section.
• RailsCasts is  like a sea of quality Ruby on Rails screencasts. Watch a few on topics where you may have doubts.
3. jQuery
• We’ll be learning jQuery assuming that all of us are already familiar with JavaScript.
• We’ll learn only basics initially and explore more as we start using it in a Rails project.
4. CoffeeScript
• CoffeeScript is a language that compiles to JavaScript but it’s way more beautiful to look at and easier to read and understand.
• We’ll not write JavaScript code for our Rails app. Instead, we’ll be writing CoffeeScript!
5. SCSS
• SCSS is an extension of CSS3. It’s fun to write stylesheets using SCSS as it brings in additional features like variables, nested rules etc.
• SCSS will ultimately be compiled to CSS.
• Again, there is not much to do here. Half an hour to familiarize yourself with the syntax and you are ready to roll.
6. Twitter Bootstrap
• Bootstrap is a super simple and crazy awesome CSS and JavaScript toolkit developed by twitter.
• We’ll be using bootstrap to power our Rails apps which we’ll build at a later stage.
• Nothing much to learn here. It’s more about getting familiar with commonly used classes.
7. Git and GitHub
• We’ll be using Git for tracking code while building our apps.
• We’ll learn about basic Git functions like cloning a repository, committing code, pushing code to a remote repository, working in different branches etc.
• Go through Git Basics and we can learn more as we start using it full time.
• We’ll be using GitHub to host all our code. If you don’t have an account already, get one.

We’ll learn these technologies while working regularly at our work places. Once in a while, we’ll meet and share our experiences and knowledge. The plan is to spend one or two weeks to go through basic stuff in all the topics. After that we can start a dummy rails project and learn more as we go.

If you are not in Hyderabad and still want to join, just start exploring and we can connect online! Happy Hacking!!!

Fedora Tutorials by Kulbir Saini.

As promised in my previous post, here is a brief howto on getting started with twython. The main advantage of Twython over several other python (or any other language) wrappers for Twitter API is that it works even when you are behind your organizations proxy.

Download Twython

You can download latest version of twython from twython page on github. You can either clone using git (if you have git installed) or can click the download button.

Install Twython

Once you are done with extracting the downloaded tar file. Change directory to twython and run these command as root.

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[root@fedora ~]$ git clone git://github.com/ryanmcgrath/twython.git
[root@fedora ~]$ cd twython/dist
[root@fedora dist]$ tar -xvzf twython-0.8.tar.gz
[root@fedora dist]$ cd twython-0.8/
[root@fedora dist]$ python setup.py build
[root@fedora dist]$ python setup.py install

Use Twython from Python Interpreter

Below is a direct copy paste lines from my interpreter. See how things are working (learning by doing).

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[saini@bordeaux ~]$ python
Python 2.6 (r26:66714, Mar 17 2009, 11:44:21) 
[GCC 4.4.0 20090313 (Red Hat 4.4.0-0.26)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> # first of all, import twython module
>>> import twython
>>> # Authenticate your twitter account with your twitter username
... # and password with twitter.setup method.
>>> client = twython.setup('Basic','myusername','mypassword')
>>> client.authenticated
True
>>> #Lets update our current status on twitter with some cool message.
>>> client.updateStatus('Testing #twython. The coolest #TwitterAPI :)')
>>> # Now go and check your current status on twitter. Surprised!!!
>>> # Get your or anyone's followers
>>> client.getFollowersIDs(screen_name='gofedora')
>>> # Output truncated.
>>> # Get help for any function.
>>> print client.createFriendship.__doc__
createFriendship(id = None, user_id = None, screen_name = None, follow = "false")
 
	Allows the authenticating users to follow the user specified in the ID parameter.
	Returns the befriended user in the requested format when successful. Returns a
	string describing the failure condition when unsuccessful. If you are already
	friends with the user an HTTP 403 will be returned.
 
	Parameters:
		** Note: One of the following is required. (id, user_id, screen_name)
		id - Required. The ID or screen name of the user to befriend.
		user_id - Required. Specfies the ID of the user to befriend. Helpful for disambiguating when a valid user ID is also a valid screen name. 
		screen_name - Required. Specfies the screen name of the user to befriend. Helpful for disambiguating when a valid screen name is also a user ID. 
		follow - Optional. Enable notifications for the target user in addition to becoming friends. 
>>>

So now you are ready to do wonders with twython. Write your own code and blog/brag about it

Fedora Tutorials by Kulbir Saini.

Goal

Setting up gitweb (web interface for SCM software git) for your project’s git repository for public access and developer commits via ssh.

Assumptions

1. You already have your project’s git repository.
2. You have hosting space somewhere to host gitweb.
3. You have root access.
4. You are using Apache as webserver.

Example for this howto

Project : VideoCache
Domain for gitweb : git.cachevideos.com
URL for git access for videocache : http://git.cachevideos.com/videocache.git
Actual path on server : /home/saini/domains/cachevideos.com/git
Git repository : /home/saini/projects/videocache/

Installation

Installation is pretty easy. Just one single command would do everything.

[root@localhost ~]# yum install gitweb (do as root)

This will create a directory /var/www/git which is default for gitweb.

Copy the directory /var/www/git/ to /home/saini/domains/cachevideos.com/git

[root@localhost ~]# cp -r /var/www/git /home/saini/domains/cachevideos.com/git

Configuration

1. GitWeb

Open the file /etc/gitweb.conf (it may or may not be there) and add the following lines to it.

# Change This
$projectroot = '/home/saini/domains/cachevideos.com/git';
# Change This
$site_name = "Kulbir Saini's git trees.";
# Don't Change the variables below
$my_uri = "/";
$home_link = '/';
@stylesheets = ("/gitweb.css");
$favicon = "/git-favicon.png";
$logo = "/git-logo.png";

2. Apache

Open the file /etc/httpd/conf.d/git.conf and clear all the lines that are already there and add the following lines to it

  DocumentRoot /home/saini/domains/cachevideos.com/git
  ServerName git.cachevideos.com
  ErrorLog "/home/saini/domains/cachevideos.com/logs/error_log"
  CustomLog "/home/saini/domains/cachevideos.com/logs/access_log" combined
  SetEnv  GITWEB_CONFIG  /etc/gitweb.conf
  DirectoryIndex gitweb.cgi
 
    Allow from all
    AllowOverride all
    Order allow,deny
    Options +ExecCGI
    AddHandler cgi-script .cgi
 
      SetHandler cgi-script
 
    RewriteEngine on
    RewriteRule ^[a-zA-Z0-9_\-]+\.git/?(\?.*)?$ /gitweb.cgi%{REQUEST_URI} [L,PT]

3. Git repository configuration

Go to your git repository (/home/saini/projects/videocache/) and make the following changes.

(a). Open file .git/description and add a short nice description for your project.

videocache is a squid url rewriter plugin written in Python to facilitate youtube, metacafe, dailymotion, google, vimeo, msn soapbox, tvuol.uol.com.br, blip.tv, break.com videos and wrzuta.pl audio caching.

(b). Open file .git/config and append the following lines

[gitweb]
  owner = "Kulbir Saini"

Copy project’s git repository for gitweb

Copy the /home/saini/projects/videocache/.git directory to /home/saini/domains/cachevideos.com/git/videocache.git

[root@localhost ~]# cp -r /home/saini/projects/videocache/.git /home/saini/domains/cachevideos.com/git/videocache.git

Finishing Step

Restart Apache webserver.

[root@localhost ~]# service httpd restart

Now you can browser a list of your projects’ git repositories at http://git.cachevideos.com/ .

Adding another project repository

Just copy the project repository’s .git directory to /home/saini/domains/cachevideos.com/git/prjoect_name.git. And it’ll be shown on the list.

Committing (pushing) to the repository

For committing to the repository via ssh use the following command.

# Pushing everything (Please see the username)
[root@localhost videocache]# git push --all ssh://saini@git.cachevideos.com/~saini/domains/cachevideos.com/git/videocache.git

To update tags on the remote repository use this command.

# Pushing all tags
[root@localhost videocache]# git push --tags ssh://saini@git.cachevideos.com/~saini/domains/cachevideos.com/git/videocache.git

Well, if you consider just the web interface and committing part for your project, thats all. But things can be fine tuned further. Below are few hacks!

1. Enabling nice urls.

By default the urls for browsing repository via git web are pretty crappy and difficult to remember. The RewriteRule and RewriteEngine lines in your Apache configuration file (/etc/httpd/conf.d/git.conf) takes care of that and produce nice and clean urls.

So you can browser the repository via http://git.cachevideos.com/videocache.git instead of http://git.cachevideos.com/?p=videocache.git;a=summary.

2. Enabling remote ls (git-ls-remote or git ls-remote)

This is the most trickiest part. If you try the command below, it won’t produce any output

[root@localhost ~]# git-ls-remote http://git.cachevideos.com/videocache.git

You need to go to project’s repository in gitweb and then run the following command to update the server info for git.

[root@localhost ~]# cd /home/saini/domains/cachevideos.com/git/videocache.git/
[root@localhost ~]# git-update-server-info

Try the ls-remote command now and it should succeed by producing all the branches and tags in the remote repository.

But there is a problem, you have to run the above command after every commit to the remote repository. To solve this issue, you can enable post-update hook for the project’s repository in gitweb. Use the following command to enable it.

[root@localhost ~]# cd /home/saini/domains/cachevideos.com/git/videocache.git/
[root@localhost ~]# chmod +x post-update

The above command will update the server info automatically every time you commit.

Thats all you need to do for setting up gitweb. I hope this will be helpful.

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Fedora Tutorials by Kulbir Saini.