Connecting to V2 Elixir app with Livebook (again)

Hi! My app has recently been upgraded to Apps V2 and my original method for connecting a livebook to my production app has stopped working.

I’ve followed the guide, swapping out the old call to fly ips private list for fly ips allocate-v6 --private followed by fly ips list to get the private IP address which – in theory at least – is accessible through my Wireguard tunnel. However, even with a (verified as working) Wireguard tunnel and a (previously working) cookie set up, livebook just won’t connect.

Does anyone have any ideas what I’m missing here please?

Solved it. Leaving this here in case someone else hits up against the same issue.

The problem stems from the CLI tool not actually reporting the private IP used by the app for its cluster naming. If you follow this guide, you’ll have a name based on the private IP as reported from the app itself, using grep fly-local-6pn /etc/hosts | cut -f 1 at the point of release. This is not the same as what gets reported by fly ips list, and also not what’s reported in the web console.

So, to get the actual node name to connect to, use fly ssh console then run that grep line to get the actual IP to use in the connection name. Bingo, you’re connected again :slight_smile: