Linotak: Link-Note Taker

In other words, yet another micro-blogging app! This one powers pdc.ooble.uk.

This app intentionally has minimal features, and does not have interaction features, other than for editors of the site.

Development

Stack:

• Python 3.10
• Django 5.2
• Celery 5.5
• ImageMagick 7

Setting up

The Linotak Notes app is designed to run a limited number of note-taking sites, which we call series, as in a series of notes. Each series has its own subdomain, and can have its author/editor or team of authors/editors. For example, if it is set up with a domain of notes.example, Alice and Bob might have respective sites https://alice.notes.example/ and https://blather.notes.example/.

Linotak has no support for online user enrolling, customer managemenet or subscriptions: it is intended for small-scale deployments, when the site admin knows the editors and any commercial arrangements are arranged elsewhere. New series and logins are created through Django’s admin pages:

Post-install

To set up a series for Marcus Valerius Martialis to publish epigrams:

1. In the admin site Customuser section, create a login with username martial.
2. In the Notes section, create a person whose login is martial and native name is Marcus Valerius Martialis.
3. Also under Notes, create a series with name epigrams and title Martial’s Epigrams.
4. Outside of Linotak, set up the domain name epigrams.notes.example and its TLS certificate (More details below).

Now Martial should be able to visit https://epigrams.notes.example/new to log in and create his first note.

We need TLS certificates so that HTTPS works: either certificates for each series, or a wildcard certificate, which is more complicated. For small-scale deployments, it is easier to use Let’s Encrypt with an explicit list of the subdomains.

Development

We need to start by creating fake domains to support the series middleware. On most Unix-like systems (like macOS and GNU/Linux) we do this by editing /etc/hosts.

We are using Poetry to organize the dependencies.

poetry install
eval $(poetry env activate)

Running tests

./manage.py check
./manage.py test

Server settings are controlled by environment variables; for development we can add them to a file .env, which is not added to source-code control.

echo >>.emv DEBUG=y

Celery needs a message broker. I use RabbitMQ

Running the server works easiest with 3 terminal windows running the following commands:

rabbitmq-server
poetry run -- celery -A ooblesite.celery worker --loglevel=info
poetry run -- ./manage.py runserver 0:8004

Testing scanning

Try this

URL=https://foo.example.com/bar
FILE=samples/foobar.html

curl $URL > $FILE
poetry run -- ./manage.py linotakscan --base=$URL $FILE

Localization

Freshen the extracted translation files with

poetry run -- django-admin makemessages -l eo

Upload .po files to <POEditor.com> and download and then run

poetry run -- django-admin compilemessages

Bookmarklet

Edit the following URL

javascript:location.href='https://pdc.ooble.uk/new?u='+encodeURIComponent(location.href)+'&t='+encodeURIComponent(document.title)

Setting up RabbitMQ

RabbitMQ is the AMQP implementation we use to coordinate Celery’s task queues.

Assuming your site is called, say, example.com config is easier if we consistently use the name example when creating databases etc., and so we will use it for the RabbitMQ virtual host and user. In a production site we can use a utility like pwgen to create passwords.

ENV=/home/example/env
SITE=example
PW=$(pwgen 40)

rabbitmqctl enable_feature_flag all
rabbitmqctl add_user $SITE $PW
rabbitmqctl add_vhost $SITE
rabbitmqctl set_permissions -p $SITE $SITE ".*" ".*" ".*"
echo >>$ENV CELERY_BROKER_URL=amqp://$SITE:$PW@localhost/$SITE