Lnd: Force-Closing a channel over Rest fails

[Richard87]

Hi, I cannot close a channel with either the rest API or lncli...

Rest API:

Client error: `DELETE https://lightningsale:***@lnd:8080/v1/channels/1198623c07ceb98ccfe4674e74d1f7b22840cc805e1a9491e9d17b88c32d98ec/0` resulted in a `400 Bad Request` response:
{"error":"type mismatch, parameter: channel_point.funding_txid, error: unsupported field type uint8","code":3}

Rest API (output index 1):

Client error: `DELETE https://lightningsale:***@lnd:8080/v1/channels/1198623c07ceb98ccfe4674e74d1f7b22840cc805e1a9491e9d17b88c32d98ec/1` resulted in a `400 Bad Request` response:
{"error":"type mismatch, parameter: channel_point.funding_txid, error: unsupported field type uint8","code":3}

Please advice :)

Also how do I force close a channel over Rest?

[halseth]

What is the result of the lncli command you are using?

[Richard87]

It works nicely :)

Closing via rest gave this result:

Client error: `DELETE https://lightningsale:***@lnd:8080/v1/channels/093a53310dffb963da5887abcc397227a6f70a355c86d75a6256719bb340869b/0` resulted in a `400 Bad Request` response:
{"error":"type mismatch, parameter: channel_point.funding_txid, error: unsupported field type uint8","code":3}

lncli:

docker-compose exec lnd lncli closechannel 093a53310dffb963da5887abcc397227a6f70a355c86d75a6256719bb340869b        
{
        "closing_txid": "c076966d9069ffd70583e3f0165d302e0c1dafc35dd273b3cd23e347cd61d9e1"
}

[MDrollette]

I think the cause of this problem is that the type of the channel_point.funding_txid is bytes, but there is a known bug with the grpc-gateway when using PopulateFieldFromPath on a bytes field.

Fixing grpc-gateway seems ideal, but it seems that there is already a duplicate string field that could maybe be used instead - though I'm not sure how.

[wpaulino]

I've been working on a patch to fix this. I have a working implementation using the string field @MDrollette was referring by merging the bytes and string field into protobuf's variant type oneof. I just need to tidy up a few more things before submitting a PR.

@Richard87, as for force closing a channel, you need to append ?force=true to the end of the request URL. Following your example, you can use curl to force close a channel with:

$ curl --insecure -X DELETE "https://lightningsale:***@lnd:8080/v1/channels/093a53310dffb963da5887abcc397227a6f70a355c86d75a6256719bb340869b/0?force=true"

You can actually use the other optional parameters available to close a channel, like target_conf and sat_per_byte by following the usual parameter style:

?force=true&target_conf=5&sat_per_byte=10

Unfortunately, we are lacking documentation for this kind of stuff. I'll probably put some time aside to include optional parameters for every RPC call in the docs.

[Richard87]

I'm pretty sure I tested with ?force=true, but I'll give it a second try!

Should all the optional parameters work "out of the box", or does it need more code?

[wpaulino]

Well it won't work yet, as the issue is still with parsing the channel_point.funding_txid as a []byte. This should be resolved with my patch.

As for the other optional parameters, they should all work out of the box.

[Roasbeef]

Fixed by #592.

[Roasbeef]

Oops, that's not merged yet. Re-opening :p