To demonstrate the use of a 64-bit container, we’ve developed a sample multi-container project that uses a few different technologies. The main idea is to plot a live chart containing the temperature and humidity of any city in the world.
- A download of the project from GitHub
- Software to flash an SD card (balenaEtcher)
- A free balenaCloud account to setup and manage the Pi Download and install the balena CLI tools - to be installed on your computer, allowing you to install the project code on the Raspberry Pi 4.
You will also need to set up environment variables from the balena dashboard:
| Name | Value |
|---|---|
| CITY_LATLNG | The code corresponding to the latitude and longitude of the desired city comma separated. Ex: 38.722252,-9.139337. |
| API_KEY | api key retrieved after signing up at https://darksky.net |
| FREQ | Frequency(in minutes) with which to retrieve weather data. |
To get the Lat & Long for your city, you can use latlong.net and type the name of the desired city, such as Lisbon or London. On the
environment variable, just combine both information comma separated such as38.722252,-9.139337.
The project is divided into three containers:
- A mongoDB database instance with persistent storage, in which we will store all data.
- A Python 3 application that fetches the weather information from the Dark Sky API and saves it to the database every minute.
- Node.js, ExpressJS, and VueJS application that fetches the data from the mongo database and displays it in a chart, which is refreshed automatically every minute.
Note, the express app is based on https://zellwk.com/blog/crud-express-mongodb/