I hit by a strange issue with Django. If I try to use a local configuration with

./manage.py shell --settings=myproject.local_settings

I got the error:

ImproperlyConfigured: The SECRET_KEY setting must not be empty

Strange because SECRET_KEY is certainly set. No stack trace, just a single line of error.

The cause turned out to be that in the main settings.py file I imported a method from one of my apps like this:

from accounts.views import render_failure
OPENID_RENDER_FAILURE = render_failure

I don’t understand why exactly this is a problem, but removing the import solved the issue. On the other hand, I needed that import as the OPENID_RENDER_FAILURE setting of the django-openid-auth package takes a callable, giving it the absolute function name accounts.views.render_failure as a string doesn’t cut it. I worked around that like this:

def render_failure(*args, **kwargs):
    from accounts.views import render_failure
    return render_failure(*args, **kwargs)
OPENID_RENDER_FAILURE = render_failure

Now everything works fine.

I used to deploy new versions of my websites like this:

1. ssh to the server
2. cd to the website project directory (under version control)
3. Update from VCS to the latest version

Doing this a few times is ok, but if you want to release frequently it’s better to automate these steps. One way to do that is using the post-receive hook of Git like this:

1. Setup a mirror repository on the server called “releases”, with a branch called “beta”
2. Make the deployment directory track the “beta” branch of the “releases” repository
3. Setup a post-receive hook in the “releases” repository to trigger a script that updates the deployment directory (perform a git pull or git checkout -f)

The goal of this setup is to simplify the deployment steps to a single git push command from my local development/test environment to the releases repository. Then thanks to the post-receive hook, the pushed changes will be automatically propagated to the deployment directory, without manually logging in to the server.

First I created the releases repository from my deployment directory:

Next I created the post-commit hook:

(Hook scripts are in the hooks/ directory of a Git repository, and must be executable.)

I typically use two branches: “beta” and “prod”, and reuse the same “releases” repository for these. The above hook script checks the branch that is being pushed to, and checks if an upgrade script exists with the filename in the format “upgrade-BRANCHNAME.sh”. The real upgrade scripts exist in my deployment directories, because I don’t want to have too much logic inside the Git repository directory, I prefer that to be together with the project itself. In the Git repository root I put only symlinks to the real upgrade scripts.

Writing an upgrade script depends on your project. Here’s an example from one of my Django sites:

The script is written in a way to be reusable in multiple of my Django sites, but you may need to adjust to match your typical deployment. The unset GIT_DIR is necessary, because it seems the variable is automatically set when the hook is executed, otherwise the git pull operation would result in the error:

remote: fatal: Not a git repository: '.'

Finally, I setup the releases remote in my local Git project:

# go to the directory of my local project
cd ~/project/dir

# add the "releases" remote
git remote add releases ssh://user@example.com/home/user/path/to/project.git

With this setup in place, deploying a new version is as simple as:

git push releases master:beta

To make it even easier, I created aliases in my .gitconfig:

deploy-beta = push releases master:beta
deploy-prod = push releases master:prod

First of all, XBMC looks really awesome:

[Show as slideshow]

I’m using XBMC mainly to watch my favorite internet streams, such as TED and vimcasts.

I’m not using it yet for my movie collection, because I have some issues with its built-in player:

• Adjusting the volume is not easy enough: in VLC I can just use the mouse scroll
• Adjusting the aspect ratio is not easy enough

Finally I figured out how to use an external player. I created a configuration file in ~/.xbmc/userdata/playercorefactory.xml like this:

This way it will use VLC for local video files only, and continue to use the built-in player for others.

For more information on hacking the configuration, see the docs.

If Apache is configured to browse a Subversion repository, its files and directories are shown as of the latest version by default, for example:

http://svn.apache.org/repos/asf/subversion/trunk/

If you want to browse the content of older revisions, there is a non-trivial way by inserting /!svn/bc/REVNO between the base URL of the repository and the path component of the target directory inside the repository, for example you can browse the contents as of revision 1234123 like this:

http://svn.apache.org/repos/asf/!svn/bc/1234123/subversion/trunk/