Over the past week or so, I’ve been working on developing a small prototype of the art project I detailed in my last post. After a bit of struggle, I set up a raspberry-pi-zero-w (a small raspberry pi with wifi in the chip) without a monitor. I also set up a Microsfot Azure account. They have a blob storage service which is perfect for storing the messages. I created a small program using Node.js to upload, download and delete messages from this service and installed it on my raspberry pi. Now I have the capability to upload, download, and delete files from a raspberry pi to Microsoft’s distributed servers.
I also created a web server using Node.js and Express. Right now the only capability of the web server is to list the files in the messages container in the blob service. It also creates a SAS (Shared Access Signature) token for each message, so that each listing on the website is linked to the file in the blob service.
The Web Server and Website
Here’s the general file structure:1
2
3
4
5
6
7-app
-public
-server
-services
-views
index.js
-build
All the files in app are processed and copied into build. Javascript is transpiled from es6 to es5 and minified, css is concatenated and minified.
The public folder contains static resources like css and client-side javascript. It’s serverd statically with express.
The server folder contains all the Node.js code to determine how the server responds to requests.
The services folder contains services used by the server. Namely, it contains a MessageService which provides methods to upload, delete, list, and get links to messages.
The views folder contains all of the html for the website. It’s written with embedded javascript so it can easily include data from the server.
index.js is the starting point for webpack, which bundles static resources.
Raspberry Pi
The program installed on the raspberry pi is just a command-line version fo the MessageService on the web server. It’s also written in javascript and run with node.js.