Run Server on Hostname

My problem: I have multiple Django projects, but when I use the dev server (./manage.py runserver), they clobber each others' cookies since they run at 127.0.0.1 by default.

The manual solution: I set my hostfile (/etc/hosts) up so that each project has its own pseudo-hostname. Usually this is "projectname.localhost". But that means I have to remember which name I gave to each project and remember to pass it every time I ./manage runserver.

This package lets me define a desired dev server hostname in my Django settings, then runserver will respect it by default. If for any reason, I want to override that setting on a one-off basis, that still works.

Installation

1. Install the django-runserveronhostname package using whatever package manager you prefer (I use uv).
2. Add runserveronhostname to INSTALLED_APPS in your Django settings.
3. Add a setting RUNSERVER_ON = 'myname.whatever:8000' (you must include a port number). This could also be used to bind to a particular IP address (RUNSERVER_ON = '0.0.0.0:8000') if you prefer.

Important note: this package doesn't do anything about making sure you can actually bind to the requested name or IP address. You will need to manually add an entry to your hostfile, DNS, etc. See the new hostfile command for some help with that.

Usage

When you run the dev server (./manage.py runserver, django-admin runserver, etc.), if you have RUNSERVER_ON defined, it'll use that. This works with any runserver implementation:

• naive implementation in Django
• staticfiles implementation in Django
• daphne's runserver override

hostfile command

You can run ./manage.py hostfile to see whether the hostname you require is listed in your system host file. Right now this only works directly on Linux and macOS, but if you know where your system's hostfile lives, you can point to it with ./manage hostfile --file <path/to/hosts>.

There's another option you can pass, --write, which will spit back the hostfile it finds and add your project's RUNSERVER_ON hostname if it doesn't already appear. If you wanted to be really bold, you could do something like:

# I don't really recommend this, it's not battle-tested
% sudo ./manage.py hostfile --write >/etc/hosts 

Contributing

While I don't mind contributions, I don't really expect any, either. So I don't have great instructions here. It's a really small package, and you can probably stand up a little test app locally with this installed in editable mode.

Running tests

At time of writing, we have 100% test coverage. That's not necessarily a strict rule, but it sure feels good to have a second set of eyes watching each line.

% uv sync --extra test && uv run pytest

Changelog

See what's changed in each version in the changelog.