lnd can create transaction below min fee rate

[akcelerator]

Background

Trying to open channel using all funds available.

Your environment

• lnd version 0.4.1-beta
• Linux 2.6.32-042stab127.2 Fix name typo in README #1 SMP
• Bitcoin Core Daemon version v0.16.99.0-2fc9437
• go version go1.10 linux/amd64

Steps to reproduce

Tried to send all funds, daemon tell me that not enough funds, so I calculate difference and use "proper" amount. Well, that not work.

rav3n@node1:~$ lncli walletbalance
{
    "total_balance": "998955",
    "confirmed_balance": "998955",
    "unconfirmed_balance": "0"
}
rav3n@node1:~$ lncli openchannel xxxx 998955
[lncli] rpc error: code = Unknown desc = not enough witness outputs to create funding transaction, need 0.00999176 BTC only have 0.00998955 BTC  available
rav3n@node1:~$ lncli openchannel  xxxx 998734
[lncli] rpc error: code = Unknown desc = -26: mempool min fee not met, 221 < 1081 (code 66)
rav3n@node1:~$ lncli openchannel  xxxx 998955
[lncli] rpc error: code = Unknown desc = not enough witness outputs to create funding transaction, need 0.00998955 BTC only have 0 BTC  available
rav3n@node1:~$ lncli walletbalance
{
    "total_balance": "0",
    "confirmed_balance": "0",
    "unconfirmed_balance": "0"
}

Expected behaviour

Open channel

Actual behaviour

Channel not open, funds gone?

[littleskunk]

mempool min fee not met is an error message from bitcoin core. Add mintxfee= to bitcoin.conf and it will work.

[Rav3nPL]

Added

mintxfee=0.00000001

and restarted daemons. Funds still "0"

[Rav3nPL]

Looks like tx is send and confirmed:
https://blockchain.info/pl/tx/a3330a16c46aff47de008207e9971e899d49f2acf8e80d2e434f6d69a84c8462,
But LN daemon is not aware of it.
Balances at zero, no channel in listchannels

[Roasbeef]

Is the channel in pendingchannels?

[Rav3nPL]

No, it was not.
Today I see BTC is back in walletbalance

lncli walletbalance
{
    "total_balance": "997820",
    "confirmed_balance": "997820",
    "unconfirmed_balance": "0"
}

I`m happy, but it is still odd.
There should be function to safely open channel using all funds available, or manually set tx fee, to not get stuck with some dust.

[Roasbeef]

You can set the fees manually for channel opening:

  --conf_target value    (optional) the number of blocks that the transaction *should* confirm in, will be used for fee estimation (default: 0)
   --sat_per_byte value   (optional) a manual fee expressed in sat/byte that should be used when crafting the transaction (default: 0)