flirror 1.1.0

A smartmirror based on Flask

Flirror - A smartmirror based on Flask

Flirror is a modular smartmirror application developed in Python. It consists of a simple webserver based on Flask which holds the UI and a command line application that retrieves information from different APIs (e.g. OpenWeather, Google Calendar, ...). Currently, there is only a small set of available modules, but I'm planning to add some more (see planned features and ideas).

Despite the number of commits, this project is still in an early phase, so I'm happy about any contribution!

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Contents: Motivation | Architecture | Usage | Available Modules | Developing Custom Modules | Deploy on Raspberry | Development | Planned features and ideas |

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Motivation

I mainly started this project because I wanted to build a smartmirror using a Raspberry Pi. I searched for existing projects and found a few, but none of them really suited my needs. There are a few smaller ones developed in Python, but most of them don't seem to be actively maintaned anymore. A very public one I found is for sure MagicMirror². I think, this is a really awesome project - taking a look at all the customizable parts, contributions and custom modules that were developed in the meantime. I'm just not much of a JavaScript developer and don't like the idea of having everything in a single application.

But I got inspired by the features it provides and decided to develop my own smartmirror in Python. Maybe someone else in the Python community is also interested in a project like this.

Architecture

Flirror mainly consists of two components - a webserver based on Flask and a command line application, the so called "crawler" that retrieves data from different APIs/backends (whatever you want to call it).

flirror-web

The webserver is mainly used to show the information that is retrieved by the crawlers. Currently, it doesn't allow any "interaction" from a user side. But maybe something like this will come in the future.

flirror-crawler

The crawler application can simply be invoked from the command line and is used to crawl the various backends / APIs for the actual data that is displayed by flirror-web. The crawler application supports two different modes: periodic and immediate (default). The periodic mode will crawl all available APIs in customizable intervals, while the immediate mode can be used as a one-shot command to retrieve the data directly from all available backends.

SQLite database

To bring both components together I decided for a very simple approach, using a local SQLite databse. I mainly made this choice, because we are only storing simple key value pairs and SQLite comes out of the box with python.

Usage

Installation

Flirror can simply be installed via pip:

$ pip install flirror

or via docker:

$ docker pull felixedel/flirror

Deploying flirror via docker is simplest using docker-compose. An example docker-compose stack can be found in the deploy/docker-compose.example.yaml file.

Configuration

Both applications - flirror-web and flirror-crawler - read their configuration from the file path given via the FLIRROR_SETTINGS environment variable, e.g.

$ export FLIRROR_SETTINGS=$(pwd)/settings.cfg

A basic configuration file must at least contain the path to a DATABASE_FILE and a list of MODULES with at least one module configured.

Each entry in the MODULES list accepts the following parameters:

Parameter	Description
id	Required The ID to identify this module inside the application.
module	Required The name of the module to use for this tile. A list of available modules can be found here
config	Required The configuration for the specific module. Some modules come up with a default configuration, but usually this is needed to for each module. For more details on how to configure the specific module, take a look at the module's configuration part in the modules section.
crawler	Crawler specific settings. This can be used to speficy e.g.the crawling interval for a specific module. For more details see the crawler config section.
display	Configure the position and reloading time of a module

An example configuration with at least one module with the minimum required parameters might look like the following:

MODULES = [
    {
        "id": "weather-tile",
        "module": "weather",
        "config": {
            "city": "My hometown",
            "api_key": "<your-openweathermap-api-key>",
            "language": "en",
            "temp_unit": "celsius",
        },
        "display": {
            "position": 0,
        },
    }
]

For more detailed configuration examples, please take a look at the settings.example.cfg file.

Each module entry defined in this configuration file will be shown as a single tile in flirror-web and will be crawled independently in flirror-crawler.

Start flirror-web

To start flirror-web, simply run the following command:

$ flirror-web

which will start a gunicorn server serving the flirror application on http://127.0.0.1. The script accepts arbitrary parameters, so you could further configure the gunicorn command that is executed in the end, by e.g. specifying the number workers or changing the address. For a list of available command line arguments, please refer to gunicorn's documentation.

If you don't want to use gunicorn, you could take a look at Flask's uWSGI guide.

Start the crawler

To start the crawler simply run one of the following commands

# Periodic mode
$ flirror-crawler crawl --periodic

# Immediate mode
$ flirror-crawler crawl

to run the crawler either in periodic or immediate mode. In both cases flirror will look up all modules specified in the configuration file and try to retrieve the data for each one by invoking the respective crawler.

Available Modules

Modules provide the base functionality that is used by Flirror to show e.g. a clock or the current weather. Every module defines a view (which is visible in flirror-web) and a crawler that retrieves the actual data from an API or backend.

Some modules may come without a crawler (like the clock module) but usually it's recommended to do any data retrieving / calculation in the crawler and use the view only to show the data.

The following modules are available in flirror by default:

• Clock
• Weather
• Calendar
• News
• Stocks

Clock

The clock module displays a clock either in digital or analog format. This is a pure JavaScript/CSS module, as it wouldn't make much sense to use a Python backend to retrieve the current time.

Configuration

Option	Description
mode	Must be one of analog or digital to display the clock in the selected format. Default: digital

Weather

The weather module displays the current weather information together with a forecast for the next six days. The weather information is retrieved from OpenWeather, so an OpenWeather API key is necessary to access those information. Information on how to get a free API key can be found in their How to start section.

Configuration

Option	Description
api_key	Required Your personal OpenWeather API key
language	Required The language in which the results are returned from the API (and thus displayd in flirror). For a list of available language codes, please refer to the OpenWeather multilingual support.
city	Required The city to retrieve the weather information for.
temp_unit	Required The unit in which the results are returned from the API (and thus displayed in flirror).

Calendar

The calendar modules displays upcoming events from a Google calendar. Currently, Flirror only supports the OAuth 2.0 for TV and Limited-Input Device Applications.

Configuration

Option	Description
calendars	Required A list of google calendars to retrieve the events from. If you don't want to mix up multiple calendars in one tile, you can configure multiple calendar modules with one calendar each. Your default google calendar is usually named after your gmail address.
max_items	The maximum number of events to show. Default: 5

Stocks

The stocks module displays current stock values either in table format or as a time series. The information is retrieved from Alpha Vantage, so an Alpha Vantage API keys is necessary to access those information. Information on how to get a free API key can be found in their Getting started guide.

Configuration

Option	Description
api_key	Required Your personal Alpha Vantage API key
symbols	Required The list of equities you want to retrieve. Each element must be in the format ("<symbol>", "<display_name>")
mode	One of table or series to display the stocks information in the selected format. Default: table

News

The news module displays entries from a RSS feed. Flirror uses the feedparser package to crawl the newsfeeds. Please take a look at feedparser's documentation to get an overview about available formats which can be parsed.

Configuration

Option	Description
name	Required The title to display over the news entries
url	Required The url pointing to the RSS feed

Developing Custom Modules

Flirror provides a plugin mechanism using an extended version of Flask Blueprints.

The so called FlirrorModule provides some decorators and functions to register the necessary view and crawler for a module. Apart from that you could still utilize the whole Blueprint functionality to provide e.g. custom templates, filters and more.

A simple module may consist of the following file structure:

flirror_awesome_module
|-- __init__.py
|-- templates/
    |-- awesome_module/
        |-- index.html

The __init__.py file contains the module's python code including the module definition itself.

import time

from flask import current_app

from flirror.modules import FlirrorModule

awesome_module = FlirrorModule(
    "awesome_module", __name__, template_folder="templates"
)


@awesome_module.view()
def get():
    return current_app.basic_get(template_name="awesome_module/index.html")

@awesome_module.crawler()
def crawl(module_id, app, user_name):
    awesome_data = {
        "_timestamp": time.time(),
        "message": f"Hello, '{user_name}",
    }
    app.store_module_data(crawler_id, awesome_data)


FLIRROR_MODULE = awesome_module

A few notes on what's going on here:

First, we create a new FlirrorModule() instance which contains all the necessary parameters of our custom module like its name, import_path and the template_folder. The latter one is necessary to make our custom template usable in Flirror.

Once the module is defined, we can use the @awesome_module.view() decorator to register the module's view function in Flirror. Using this decorator will register a new route /awesome_module/ on the underlying Flask application. Flirror-web will then request this route while providing the module_id as GET parameter. The helper function basic_get() will evaluate this GET parameter, look up the data which is stored in the database for this module_id and populate the data to the template provided via the template_name parameter. Finally, it returns the rendered template so that flirror-web can integrate it in its UI.

To store the data in the database, we provide a crawler function decorated with @awesome_module.crawler(). This registers the function as crawler for this module in flirror. When invoking flirror-crawler this function will be called with a set of predefined parameters:

• The module_id for which the function is called
• The app (which is mainly used as a back-reference to get access to the database)
• All config values that the module provides. In our case we want to greet a user whereby the user_name is configurable. Usually there is no need to store the user_name in the database as we could also directly access it in the view. It's just used like this to show the typical use case of view and crawler.

Finally, we expose our module as FLIRROR_MODULE so that it can be detected by Flirror.

The templates/awesome_module/index.html file contains the view's HTML code in form of a Jinja2 template. It might look redundant that the module's name is specified again in the path to the template. That's necessary to avoid overriding templates of other modules. More information on this can be found in the Templates section of Flask's Blueprint documentation.

{% extends "module.html" %}

{% block body %}
<div class="card-body">
    <div class="text-right">
        <small>
            <i id="{{ module.id }}-spinner" class="fas fa-sync-alt"></i> {{ module.data._timestamp | prettydate }}
        </small>
    </div>
    <h2>{{ module.data.message }}</h2>
</div>
{% endblock %}

To seamlessly include the module's view in the flirror-web UI, make sure to extend the module.html template and use <div class="card-body"> as outer element in the body block.

Module Detection

Flirror will try to detect installed plugins automatically if they follow a predefined naming schema. For each plugin found, Flirror will look up the provided flirror modules and register them on the app.

To make your plugin discoverable by flirror, it must fulfil the following requirements:

• The name of python package providing the custom module (or modules) must start with flirror_ (e.g. flirror_awesome_module).

• The package must expose the modules via one of the following top-level variables:

  # To expose a single module, use
  FLIRROR_MODULE = <my_awesome_module>
  # If the plugin provides multiple modules, expose them via
  FLIRROR_MODULES = [<my_awesome_module_1>, <my_awesome_module_2>]
  

• Each module must be a valid FlirrorModule instance.

Flirror's standard modules are defined in the same manner like custom modules, thus you could take a closer look on their source if you are interested in how you could develop a custom module.

Deploy Flirror on a Raspberry Pi

Although Flirror could simply be installed via pip, the recommended way to install it on a Raspberry Pi is via Docker. The main reason for this is that not all python dependencies are packaged for ARM and thus must be built from sources. This takes a lot of time (up to 60 minutes) especially for those using C extensions.

Flirror's Docker image already comes with all dependencies installed and you can directly start Flirror after pulling the image.

Requirements

• Docker
• docker-compose

Install docker

To install docker on raspbian OS, you can simply run the following command:

$ curl -sSL https://get.docker.com | sh

This will download the installation script and directly execute it via shell. Running the script may take some time. Afterwards, you might want to add your user (pi) to the docker group, so you can run docker without sudo:

$ sudo usermod -aG docker pi

Afterwards log out and back or reboot the Raspberry Pi via

$ sudo reboot -h

Install docker-compose

There are various ways to install docker-compose. Please see the docker-compose installation guide for more detailed information.

I personally installed docker-compose via pipx. Using this variant requires the python-dev and libffi-dev packages to be installed on the system.

$ sudo apt install python-dev libffi-dev
$ python3 -m pip install --user pipx
$ python3 -m pipx ensurepath
$ pipx install docker-compose

Start flirror

Both componenents can be started using the docker-compose file provided in deploy/docker-compose.example.yaml. Just copy this file, change some of the volume mounts (if necessary) and run

$ docker-compose up

to start the web server and the crawler in periodic mode.

With both services running we still need to open some browser to see the actual flirror UI. Therefore, you could download and execute the following helper script like so:

$ wget https://raw.githubusercontent.com/felixedel/flirror/master/helpers/start_gui.sh
$ chmod u+x start_gui.sh
$ ./start_gui.sh

Apart from starting chromium in full screen mode pointing to the running flirror-web instance inside the docker container, this script will also ensure that some necessary environment variables like DISPLAY are set and that the screen saver and energy saving mode of the X server are disabled - so the display doesn't go into sleep mode after a few minutes.

Optional configuration

To hide the mouse cursor, install unclutter via

$ sudo apt install unclutter

and add the following line to /home/pi/.config/lxsession/LXDE-pi/autostart

@unclutter -display :0 -noevents -grab

Development

Use docker buildx for a multi-architecture build

To use the Flirror docker image on a Raspberry Pi, it must be built for the ARM architecture. To not always utilize a Raspberry Pi itself to build the docker image for ARM, we could use docker's buildx command and run a multi-architecture build on Linux or Mac.

When using Docker for Mac, the buildx command should already be available. You just have to enable the "experimental features" in the "Command Line" section of the application's settings.

For Linux, you could use the Getting started with Docker for Arm on Linux guide to install buildx.

To test if the docker buildx command is available, simply run

$ docker buildx --help

To show the available platforms for which buildx can be utilized, run

$ docker buildx ls

Docker for Mac already comes with a few preinstalled platforms including linux/arm/v7 (which we are going to use).

For Linux, you first need to register the ARM executables via qemu. Information on how to achieve this can also be found in the guide mentioned above.

Once everything is set, we can create a new builder instance which we will use for our multi-archtitecture build:

$ docker buildx create --name flirrorbuilder
$ docker buildx use flirrorbuilder
$ docker buildx inspect --bootstrap

This will download the necessary buildkit docker image and should show an output similar to the following if successful:

[+] Building 12.1s (1/1) FINISHED
 => [internal] booting buildkit                                                                 12.1s
 => => pulling image moby/buildkit:buildx-stable-1                                              11.0s
 => => creating container buildx_buildkit_flirrorbuilder0                                        1.0s
Name:   flirrorbuilder
Driver: docker-container

Nodes:
Name:      flirrorbuilder0
Endpoint:  unix:///var/run/docker.sock
Status:    running
Platforms: linux/amd64, linux/arm64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/arm/v7, linux/arm/v6

Now we can use this builder to build the Flirror multi-architecture image with the following command:

$  docker buildx build --platform linux/arm,linux/amd64 -t felixedel/flirror:latest -f dockerfiles/flirror-Dockerfile --push .

Planned features and ideas

• A plugin mechamisn to allow custom modules to be included in flirror
• Provide webhooks to allow interacting with flirror from the outside (and maybe event between modules)
• Provide some notification mechanism