Ubuntu-11.04-Subversion – The Trac Project

Ubuntu-11.04-Subversion – The Trac Project:

Installing Trac with Subversion on Ubuntu

The goal of this tutorial is to demostrate how to setup a Subversion ↔ Trac enviroment on Ubuntu 10.04. A MySQL database and Subversion Python bindings are going to be used. Please note that only general instructions are provided, and it's asummed that you have basic knowledge on Linux administration.

Note: for a full installation tutorial on Trac, please read TracInstall

Installation Steps

1. Installing the software and its dependencies
   1. Base packages
   2. Subversion
   3. Trac
2. Configuring
   1. Subversion
   2. Setup the MySQL database
   3. Trac
   4. Apache
3. Automatic reference to the SVN changesets in Trac tickets

Installing the software and its dependencies

Base packages

In order to get Trac and Subversion installed, you will need to get a few packages listed below. Also, make sure your system is updated.

sudo apt-get install apache2 libapache2-mod-python python-setuptools python-genshi mysql-server python-mysqldb

Subversion

Installing Subversion (SVN) is pretty straight forward. Just run:

sudo apt-get install subversion

Trac

There are different ways of installing Trac. But since this tutorial is focused on Ubuntu, you'll do the Ubuntu way:

sudo apt-get install trac 

Configuring

This part is maybe the most important section on this tutorial. You'll learn how to syncronize Trac and Subversion in order to be able to see on your Trac Project website what's going on in your repository and also how to automate some tasks.

Subversion

Creating the project

You may already know how to do this, but let's make a review just in case.

Create a directory to store the SVN projects:

sudo mkdir /var/lib/svn

Create a the project directory:

sudo mkdir /var/lib/svn/YourProject

Use svnadmin to create a project in the previously created folder:

sudo svnadmin create /var/lib/svn/YourProject

In order to perform some changes to the project, Trac needs write access to it:

sudo chown -R www-data /var/lib/svn/YourProject

Start the Subversion server (or use your preferred method):

sudo svnserve -d

Setup the MySQL database

Before configuring your new Trac project, you'll need to setup the MySQL database.

Log into MySQL database, using the root credentials you've setup during the installation:

mysql -u root -p

Once logged in, create the database for Trac:

CREATE DATABASE trac DEFAULT CHARACTER SET utf8 COLLATE utf8_bin;

Now create the username which Trac is going to use to connect to the database:

GRANT ALL ON trac.* TO trac@localhost IDENTIFIED BY 'yourpassword';

You can now exit the MySQL command line.

Trac

Initiate the enviroment

Let's create a directory to contain all the Trac project (just like we did for SVN projects).

sudo mkdir /var/lib/trac

Create a directory where to store the Trac project in:

sudo mkdir /var/lib/trac/YourProject

As you did for Subversion, change the ownership of the project files to Apache's user www-data:

sudo chown -R www-data:www-data /var/lib/trac/YourProject

Use trac-admin to create the new project:

sudo trac-admin /var/lib/trac/YourProject initenv

Also you will need to fill in some information, like the project name. It will ask you for the MySQL connection string. Input the following (according to the way we did setup the MySQL database in the step 2.2).

mysql://trac:yourpassword@localhost/trac

Pay attention to the question about the location of the Subversion project. Enter the path as discussed before:

/var/lib/svn/YourProject

If the MySQL default engine wasn't InnoDB, you might need to convert the tables tha trac-admin has just created. Issue the following within your MySQL client:

USE trac; \
ALTER TABLE `attachment` ENGINE = InnoDB; \
ALTER TABLE `auth_cookie` ENGINE = InnoDB; \
ALTER TABLE `cache` ENGINE = InnoDB; \
ALTER TABLE `component` ENGINE = InnoDB; \
ALTER TABLE `enum` ENGINE = InnoDB; \
ALTER TABLE `milestone` ENGINE = InnoDB; \
ALTER TABLE `node_change` ENGINE = InnoDB; \
ALTER TABLE `permission` ENGINE = InnoDB; \
ALTER TABLE `report` ENGINE = InnoDB; \
ALTER TABLE `repository` ENGINE = InnoDB; \
ALTER TABLE `revision` ENGINE = InnoDB; \
ALTER TABLE `session` ENGINE = InnoDB; \
ALTER TABLE `session_attribute` ENGINE = InnoDB; \
ALTER TABLE `system` ENGINE = InnoDB; \
ALTER TABLE `ticket` ENGINE = InnoDB; \
ALTER TABLE `ticket_change` ENGINE = InnoDB; \
ALTER TABLE `ticket_custom` ENGINE = InnoDB; \
ALTER TABLE `version` ENGINE = InnoDB; \
ALTER TABLE `wiki` ENGINE = InnoDB;

Explicit syncronization

Note: For more information about the Explicit Syncronization method, please read TracRepositoryAdmin#ExplicitSync

First, edit the trac.ini file, located in /var/lib/trac/YourProject/conf/. Modify the "repository_sync_per_request" directive and set it to an empty value.

Now you need to create the Subversion hooks. First, create the post-commit hook the in /var/lib/svn/YourProject/hooks/ directory, with the following content:

#!/bin/sh
export PYTHON_EGG_CACHE="/path/to/cache/dir"
/usr/bin/trac-admin /var/lib/trac/YourProject changeset added "$1" "$2"

Make sure you give the script execution perms:

sudo chmod +x /var/lib/svn/YourProject/hooks/post-commit

Another important hook script to have is post-revprop-change. The procedures are similiar as above, but the script is slightly different:

#!/bin/sh
export PYTHON_EGG_CACHE="/path/to/cache/dir"
/usr/bin/trac-admin /var/lib/trac/YourProject changeset modified "$1" "$2"

Again, make sure you give exec perms to the script.

Now Trac will be notified about changes you make to your repository and will make them availables in the timeline.

Apache

Set up Trac handling

Apache needs to know how to handle Trac. Use the following block to set up Trac handling:

<Location /projects> #set up Trac handling
    SetHandler mod_python
    PythonHandler trac.web.modpython_frontend
    PythonOption TracEnvParentDir /var/lib/trac
    PythonOption TracUriRoot /projects
</Location>

Note that it's pointing to the main Trac directory. It means it will expose all of your Trac projects. You may need to apply this configuration to Apache:

sudo a2ensite trac

Authentication

In order to allow users to log in Trac, you will need the following section in your Apache configuration:

<LocationMatch "/projects/[^/]+/login">
    AuthType Basic
    AuthName "Trac"
    AuthUserFile /var/lib/trac/.htpasswd
    Require valid-user
</LocationMatch>

You should now create the .htpasswd file, with an admin user:

sudo htpasswd -c .htpasswd admin

Go ahead and restart Apache:

sudo /etc/init.d/apache2 restart

Finally, you must grant admin rights to the user you've just created:

sudo trac-admin /var/lib/trac/YourProject permission add admin TRAC_ADMIN

Automatic reference to the SVN changesets in Trac tickets

Something useful is to reference tickets on your commits. That way you can keep a better track of them and also easly access them from the timeline.

Make sure you have the following line in your trac.ini configuration file:

[components]
tracopt.ticket.commit_updater.* = enabled

Now, whenever you commit some change related to a ticket, use Refs #tn to reference this changeset in #tn ticket. For example:

svn commit -m "Refs #123 - added this and that"

In order to mark a ticket as fixed, use the following:

svn commit -m "Fixes #123 - Removed an infinite loop which was causing the application to freeze"