Internet thresholds checker

Context

During the years at the University in Turin my only internet access was a router with a mobile metered connection. I had 30 Gb each month (I then switched to 100 Gb / month).
Since the internet consumption was not linear, It was easy to exceed the monthly threshold without noticing. Hence I frequently had to pay more than the planned amount.

The obvious solution would have been to upgrade to an unlimited connection, but I was learning to program, so I opted for the funnier solution ... that is this project.

Structure

This project is composed by 3 main sub-projects:

1. A set of APIs written using Flask and a background scheduler to get stats and to periodically check if those stats are below a certain threshold
2. A React website to get stats directly from the browser
3. An Android application/widget written in Kotlin to get stats and interact with the mobile router directly from the smartphone's homescreen

1 - Flask APIs

The APIs available are:

• /status get the current status
• /weekly_readings get a list of all statuses during the current week

Example of a response from /status

{
  "status": {
    "reading": {
      "total_gb": 7.5,
      "remaining_gb": 6.5,
      "date": "2021-12-05T17:04:35.814523"
    },
    "connected": true,
    "traffic_exceeded": false
  },
  "details": {
    "percentage": 86.66666666666667,
    "days_to_renew": 7,
    "actual_remaining_gb": 6.125,
    "mean_daily_left_gb": 1.0208333333333333,
    "actual_daily_left_gb": 0.7249999999999996
  }
}

The underlain login behind /status get called every 20 minutes by a background scheduler. That logic automatically switch on/off the router based on a daily threshold (more or less monthly total / 30) and on a fixed threshold (300 Mb to the paying threshold).

2 - React website

Just a simple React website with the APIs information displayed

3 - Android application and widget

With the Android widget it's possible to gather the same information of points 1 and 2, but directly from the smartphone's homescreen. This has been the most useful part of the project 🤓.
With the green and red buttons it's possible to turn on/off the internet from the router.

Docker

The Flask APIs and the React website can be launched easily using docker and docker compose with the command:
$ docker-compose up