It's kind of sad to see nodes shutting down or just turning off and the network gradually shrinking.
I have been looking at the possible failure modes of lightning while a possible fork (however short) could possibly happen. I gathered some insight earlier, and still I don't want the hassle of watching 2 separate chains while this plays out. Or perhaps is already over?
In any case, what precautions are you taking?
Not turning off your node is the best of precautions. If anything you want more monitoring, not less, and your Lightning node is already monitoring the chain the underlying Bitcoin node is on.
If you have a channel with a peer on the other side of the fork, the only important precaution to have is if you're on the minority chain, to check that your peer isn't stealing from you by publishing a revoked state on the majority chain.
The question is how you do identify a peer on the other side of the fork?
That's a good question. Usually BIP110 node operators are quite vocal about it. I'd say if they have a public profile and don't specify it's quite safe to assume they don't run BIP110. You could also ask them if they're a public facing node.
Now that the fork happened, I guess another way would be to test sending a payment through their node: they should refuse if on the other side, since block heights don't match and hence the HTLC would be invalid to them. In LND you can specify the outgoing chan ID of a payment with the
--outgoing_chan_idof thesendpaymentcommand.The whole "close your channels" PSA was one of the most damaging parts of this fiasco. Glad no one did that with me.