Subversion

Subversion is a replacement for CVS based on current technologies such as HTTP and WebDAV.

The website on tapioca is managed using subversion. All pages for the tapioca website are checked in a subversion repository at http://sw.deri.org/svn/. The repository is hourly checked out per cron job into /var/www, where the web site resides. That's why, if you make changes to global pages (i.e. pages that you don't "own" in your own home folder), these changes will take some time to come into effect.

More and detailed information about subversion can be found in the book by O'Reilly, which can downloaded here (legally).

Features

• accessible from all platforms, support for Mac OS X, Windows, Unix and development tools such as Eclipse
• open source CVS replacement based on modern standards (WebDAV, HTTP)
• integrates nicely with Apache2 http server
• access control based on Apache2 http server possible (with LDAP backend support)

Overview

• User
• Import a directory
• Check out a directory
• Check changes
• Update
• Commit
• Set ID (visual versioning)
• Delete something
• Restore your stuff after a crash
• Admin
• Create a Repository
• Add a User
• Add a Group

svn import directory/ http://sw.deri.org/svn -m "your comment"

Note that directory/ should contain the YYYY/MM/proj subfolders (i.e. 2004/03/subversion). Please provide a comment with every change.

svn checkout http://sw.deri.org/svn

Create a local copy of the web site.

svn status

Check changes between repository and local copy.

svn update

Updates local copy from repository.

svn commit -m "some comment"

Commit changes in local copy to the repository. You always have to supply a comment!

svn propset svn:keywords Id filename

Automatically change Id in filename with every update.

svn (delete|rm|remove) filename

Remove file with filename from the repository. Directories are only visibly removed after you commit the changes!

After the recent crash of the subversion system, our glorious admin tried to recover everything with the tools provided by subversion. Unfortunately, due to low-level problems, it didn't work completely. So here is what I did to recover my own stuff:

• Because I had a local working copy, the data was still there. After all, only the server was affected.
• I exported my working copy into a new directory: svn export $PATH_TO_LOCAL_REPOSITORY $NEW_PATH. This makes a copy of your working copy, and strips it of all the svn-related files (i.e., all the .svn directories). This is necessary to be able to reimport it later!
• Since my working copy and the repository on the server were no longer in sync (due to the crash), I had to check out a new version of the repository (effectively creating a new local copy): svn co http://sw.deri.org/svn/my_stuff.
• Within that new working copy, I deleted everything: svn delete *, and commited the deletions: svn commit -m "deleted everything".
• Then I copied everything from my old working copy (which still had all my precious data) into the new working copy (which was now practically empty).
• Once it is physically in there, I have to tell svn to add it to the repository during the next commit: svn add *.
• I also had to reset the Id parameter on all the relevant files... No way around that, I guess. Look here for instructions.
• Finally I commited everything again: svn commit -m "added everything again"

OK, I hope that helps and makes sense...

# svnadmin create /var/lib/svn/repository

Create repository. chown -R www-data.www-data repository, change /etc/apache2/dav_svn.conf and add the repository to the site structure.

# htpasswd -m /etc/apache2/auth-file username

Create user for use in Apache2's httpd (subversion and other http-based access control).

# vi /etc/apache2/group-file

Add a user to a group. Currently, only users belonging to group "deri" can update the subversion directory.

Access Control

To restrict access to certain users or groups, change /etc/apache2/sites-enabled/svn and add along the lines of

<Location "/2006/04/swseminar">
        Require group deri
</Location>