Unable to change a private channel to make it public

[sohomang]

Background

No API command permits to change a private channel to make it public (and vice versa). Some wallets like Zap iOS open channels as private by default and this characteristic seems unalterable for now.

(Opened an issue on lnd and learned it was something handled by the protocol itself. lightningnetwork/lnd#3230)

Your environment

• lnd version 0.6.1-beta
• bitcoind version v0.18.0
• Raspbian GNU/Linux 9 (Stretch)

Steps to reproduce

• Open a channel from GUI/CLI and make it private (somehow)
• ???
• Profit

Expected behaviour

A command should exist to let users toggle their channels' privacy settings while they're open/active.

Actual behaviour

Users have to closechannel then openchannel again to reset their private setting, which pollutes the blockchain with 2 transactions.

[ZmnSCPxj]

Toggling seems to not make sense. Once a channel is published it has been published and now exists in the routemap of nodes all over the world.

However, a one-time promotion from unpublished to published would work.

(I do not agree that they are "private" since, as long as they remain unpublished, every transaction going through it is definitely known to arise from/terminate to you, thus not particularly private.)

[Czino]

Has any more consideration been done on this front? I have come across multiple cases, where somebody had to close a private channel just to reopen it as public.

I also don't see any particular issue with having a one way of going from private to public unless there's a good technical reason why this is and should not be possible.

[faustinoaq]

I think we need this, I opened a private channel by mistake (I wanted it public) and now I have to close it and open it again as public 😢

[adamj7]

Would love to see this implemented. Private > Public 1 way only.

[ShahanaFarooqui]

Reference Core lightning issue: ElementsProject/lightning#7438
Reference LND issue: lightningnetwork/lnd#7902

[Roasbeef]

With the new gossip revamp, we'll again a way to upgrade private channels to public channels, as nodes can optionally choose to advertise their old channels in the new gossip network.