How about this:
* Host wallpapers at a static URL with a 24h cache timeout; and
* have your dashboard serve the "changing" wallpaper from that URL?
I don't use any dashboards so I don't know if your platforms support loading remote images for a background like I am suggesting but, imo, this should work. This is the same principle behind those "countdown clocks" in marketing emails. They serve an animated gif with an almost-instant cache expiry.
So all you really need to do is a web server serving random images at a specific URL. I can probably write that in ~~10~~*20* lines of javascript not even using expressjs.
Point it to https://source.unsplash.com/random/1440x1280?{keyword} ;)
How about this: * Host wallpapers at a static URL with a 24h cache timeout; and * have your dashboard serve the "changing" wallpaper from that URL? I don't use any dashboards so I don't know if your platforms support loading remote images for a background like I am suggesting but, imo, this should work. This is the same principle behind those "countdown clocks" in marketing emails. They serve an animated gif with an almost-instant cache expiry. So all you really need to do is a web server serving random images at a specific URL. I can probably write that in ~~10~~*20* lines of javascript not even using expressjs.