lnd_check_logs_for_capacity_failures.py

import subprocess

def getlndchannels(chanstofix):
	cmd = subprocess.Popen(r'"C:\Users\pseudozach\AppData\Local\Node Launcher\lnd\lnd-windows-amd64-v0.5.2-beta\lncli.exe" listchannels', shell=True, stdout=subprocess.PIPE)
	chanlist = []
	listindex = 0
	for line in cmd.stdout:
		if b"active" in line:
			#line starts
			gotline = True
		if b"remote_pubkey" in line:
			#print("remote_pubkey::" + str(line))
			rpubkey = str(line).split('"remote_pubkey": "')[1].split('",')[0]
		if b"chan_id" in line and gotline:
			#print("lndchannels::" + str(line))
			chanid = str(line).split('"chan_id": "')[1].split('",')[0]
			#print("index:: " + str(listindex) + ", " + chanid)
			chanlist.append([chanid, rpubkey])
			#chanlist[listindex][1] = rpubkey
		if b"private" in line:
			#line ends
			gotline = False
			listindex = listindex + 1
	
	#print("chanlist::")
	#print(chanlist)
	
	for chantofix in chanstofix:
		#print("finding channel:: " + str(chantofix))
		for channel in chanlist:
			#print("comparing chantofix with channel0::" + str(chantofix[0]) + ", " + channel[0])
			if str(chantofix[0]) == str(channel[0]):
				print("found it::")
				print(str(channel[1]))
				print("Liquidity Amount::" + chantofix[1])
				print("Date:: " + chantofix[2])
				print("")
				
		
def lnd_to_cl_scid(s):
    block = s >> 40
    tx = s >> 16 & 0xFFFFFF
    output = s  & 0xFFFF
    return (block, tx, output)

def cl_to_lnd_scid(s):
    s = [int(i) for i in s.split(':')]
    return (s[0] << 40) | (s[1] << 16) | s[2]

def checklogs():	
	print("checking logs for failed htlc forwards...")
	f = open("c:/Users/pseudozach/AppData/Local/Lnd/logs/bitcoin/mainnet/lnd.log", "r")
	searchlines = f.readlines()
	f.close()
	failedchanids = []
	for i, line in enumerate(searchlines):
		if "unhandled error while forwarding htlc packet over htlcswitch: unable to find appropriate channel link insufficient capacity" in line: 
			for l in searchlines[i:i+3]: 
				if "unhandled error while forwarding htlc packet over htlcswitch: unable to find appropriate channel link insufficient capacity"  in l:
					#print(l)
					#print("splitting::")
					channellink = l.split('ChannelLink(')[1].split(")")[0]
					#print channellink
					lndchanid = cl_to_lnd_scid(channellink)
					#print "lndchanid::"
					#print lndchanid
					amount = l.split('need ')[1].split(" mSAT")[0]
					datetime = l.split(' [ERR]')[0]
					element = [lndchanid, amount, datetime]
					failedchanids.append(element)
	
	#print("found failed forwards::" + str(len(failedchanids)))
	#for j, failedchan in enumerate(failedchanids):
	return failedchanids
		

def main():
	print("starting channel checker by pseudozach...")
	chanstofix = checklogs()
	getlndchannels(chanstofix)

main()