A way to remotely attach in hidden mode

[DaniruKun]

At the moment, if you have a multi-node cluster running OTP 25, and you want to connect a Livebook instance in attached mode to a node, you will be met with an error like:

'global' at node 'myuser@sora.local' requested disconnect from node 'myapp@172-30-122-113.myapp-headless.myappns.svc.cluster.local' in order to prevent overlapping partitions

This is easily solved in iex by passing the --hidden flag to use a hidden node, however there is no easy way to enable this for Livebook. It would be great to provide a similarly named flag.

[josevalim]

In this case you would need to start Livebook itself as a hidden node. How are you starting it?

[josevalim]

Hrm, yes. -hidden is a boot flag... so we would need to find a way to pass it to escripts.

[DaniruKun]

It might need to be passed to emu_args in escript, but need to investigate this: https://hexdocs.pm/mix/main/Mix.Tasks.Escript.Build.html#module-configuration

[josevalim]

Oh:

The configuration of the Erlang emulator invoked by escript can be controlled using the environment variables understood by erl.

So you can do:

ERL_AFLAGS=-hidden livebook server --default-runtime attached:remoteNodeName:cookie --name localNodeName livebookFile.livemd

[DaniruKun]

Ah nice it works like a charm! However, doing that makes the cell output capture orphan log output again...

[DaniruKun]

Nvm it was just an old Livebook version, now it works fine, thanks! I'll have to write a blog post about all of this at some point haha.