XOR Media

Coding, Operations, Etc.

Django ALLOWED_HOSTS and Amazon Elastic Load Balancer

A recent Django security release added a new configuration option, ALLOWED_HOSTS. It's optional in 1.3 and 1.4, but required in 1.5 setups. The relevant detail is that when enabled in production Django will throw 500 errors if the Host header doesn't match one of the ...

(more)
In ops, tagged: aws, django, elb, and python.

Django Model Validation On Save

In what is probably my biggest WTF with Django to date, it doesn't validate your models before saving them to the database. All of the necessary code exists and when a dev sets up her models she usually adds the relevant validations using EmailField, URLField, blank, null, unique, ..., but ...

(more)

Django Startup Signal

If you've spent some time with Django chances are you've run across its signals system. It is most commonly used to provide hooks in to the model setup and CRUD processes, but there are many other uses of the facility throughout the code including auth, db, and the ...

(more)
In code, tagged: django, signals, and python.

Efficiently Querying for Nearby Things

It's a fairly common use case to have a latitude and longitude and want to find the closest objects to a given point. While there are heavyweight solutions: MySQL Spatial Extensions, PostGIS, they can be more trouble than they're worth especially if you're making use of an ...

(more)
In code, tagged: algorithms, db, examples, geo, mysql, performance, and sql.

Extract a Video Clip on the Command-Line with avconv (ffmpeg)

If you want a quick and easy way to extract a clip from a larger video it doesn't get much simplier than using avconv (the new ffmpeg.) All you need to know is the start time and duration of the section you'd like to extract. Once you have ...

(more)
In misc, tagged: command-line, linux, and video.