Coffee Pot

The awesome webcam bot that watches your coffee pots and can be integrated with Slack. It is designed to be run on a Raspberry Pi with a camera module, and running on Resin.io OS.

Local development

Clone the repository

Make a local clone of this repository:

git clone [email protected]:ktkiiski/coffee-pot.git
cd coffee-pot

Python 3 virtualenv

To run Python scripts locally, create a virtualenv for them. You must use Python 3. Run these in your local repository directory:

mkvirtualenv -a . --python=python3.5 coffee-pot
pip install -r requirements.txt

On the following terminal sessions, run the following command to re-activate the virtualenv and switching to the working directory:

workon coffee-pot

Create Amazon S3 bundle

In order to work, you need a Amazon S3 bundle to which the captured images will be loaded. You also need to create an access key and a secret that allows uploading files to your bucket.

Configuration

You then need to configure some environment variables. Your virtualenv post-activate hook is a nice place to do this:

nano $VIRTUALENVWRAPPER_HOOK_DIR/postactivate

Then add this to the file:

# Your Slack webhook URL. Required if you want to make Slack notifications
export SLACK_WEBHOOK_URL="https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX"
# Your AWS access key used to access the storage buckets.
export AWS_ACCESS_KEY_ID="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
# Your AWS secret access key used to access the storage buckets.
export AWS_SECRET_ACCESS_KEY="abcdefghijklmnopqrstuvwxyz1234567890"
# The region to connect to when storing files.
export AWS_REGION="eu-central-1"
# The S3 bucket used to store uploaded files.
export AWS_S3_BUCKET_NAME="coffee-pot"
# A prefix to add to the start of all uploaded files. Defaults to "media".
# Allows sharing the same bucket with multiple environments.
export AWS_S3_KEY_PREFIX="__dev_media"

For all configuration options, see Environment variables below!

Then re-activate your virtualenv:

deactivate && workon coffee-pot

Repository structure

Here's the function of different folders:

• barista: The Django-powered HTTP server project folder. It contains a WSGI server application.
• coffeestatus: The Django "app" that is run by the barista project. It handles the command requests made from Slack.
• webcam: The Django "app" Python module containing database models for storing webcam photos, as logic for taking them.
• examples: Contains some example webcam snapshot files for local development, when an actual Raspberry Pi camera module is not available. When taking a snapshot, one of these images are chosen randomly.

Running the HTTP server

The app runs a HTTP server, implemented with Django for processing commands sent from Slack.

Before you run the server for the first time, you should initialize the SQLite database:

python manage.py migrate
python manage.py loaddata labels

This will run database migrations, creating a file db.sqlite3 to the root of the repository (excluded from version control). The second line loads the default labels.

You can then start the server:

python manage.py runserver

Capturing pictures

You can capture images by using the capture Django command:

python manage.py capture

You can capture conditionally only if the current time matches the configured schedules:

python manage.py capture --scheduled

If there is fresh coffee, you may also notify Slack, according to the configuration. Note that this only works if the SLACK_WEBHOOK_URL environment variable is configured.

python manage.py capture --notify

Label prediction is done by default. You can disable it if you wish (but this also disables Slack notifications):

python manage.py capture --no-predict

More information:

python manage.py help capture

Environment variables

The app must be configured with the following required environment variables:

Environment variable	Description
AWS_ACCESS_KEY_ID	Your AWS access key used to access the storage buckets.
AWS_SECRET_ACCESS_KEY	Your AWS secret access key used to access the storage buckets.
AWS_REGION	The region to connect to when storing files.
AWS_S3_BUCKET_NAME	The S3 bucket used to store uploaded files.

The may be also configured with the following optional environment variables:

Environment variable	Description
AWS_S3_KEY_PREFIX	A prefix to add to the start of all uploaded files. Defaults to media. Allows sharing the same bucket with multiple environments.
AWS_S3_KEY_PREFIX_STATIC	A prefix to add to the start of all static files when stored in Amazon S3 (in production). Defaults to static.
DATABASE_URL	The database URI that configures where the SQlite database file is stored. E.g. sqlite:////data/db.sqlite3. This already has a meaningful default in both local development and in the Dockerfile
SLACK_WEBHOOK_URL	The Slack incoming webhook URL to which Slack notifications are made. If not enabled then Slack notifications will be disabled.
SLACK_COMMAND_TOKEN	The token that is required by Slack command requests. If not defined, then no token validation is done.
SNAPSHOT_SCHEDULE_TIMEZONE	The timezone in which the snapshot scheduling is set up. E.g. Europe/Helsinki. Defaults to UTC
SNAPSHOT_SCHEDULE_INTERVAL	The number of minutes between scheduled snapshots. Defaults to 1
SNAPSHOT_SCHEDULE_START_TIME	The time of the day when the scheduled snapshots begin, e.g. 07:00. Defaults to 00:00
SNAPSHOT_SCHEDULE_END_TIME	The time of the day when the scheduled snapshots end, e.g. 17:00. Defaults to 23:59
SNAPSHOT_SCHEDULE_WEEKDAYS	Comma separated list of integers, describing on which week days the scheduled snapshots are taken. Monday is 1, Tuesday is 2, and so on. E.g. 1,2,3,4,5. Defaults to every day.

To read

• Getting Started with Raspberry Pi 1 or ZERO and Node.js
• picamera documentation