bitcoin-cli-wrapper.sh

#!/bin/bash

# bitcoin-cli wrapper for running c-lightning with a pruned Bitcoin node
# (EXPERIMENTAL). It forwards all requests to bitcoind. If a getblock request fails,
# blockstream.info is queried instead. If your prune setting is high enough (2 weeks
# = 2016?) using this wrapper SHOULDN'T have security implications because the
# important blocks are still queried through your own bitcoind.
# Tested with c-lightning 0.6.2. Set the --bitcoin-cli=PATH option in c-lightning to
# the path of this file to use it.
BCLI=bitcoin-cli

getblock() {
    hash=$1
    txids=$(curl -H "Accept: application/json" https://blockstream.info/api/block/"$hash"/txids 2> /dev/null)
    if [[ $txids = *[![:ascii:]]* ]]; then
        exit 1
    fi
    echo "{ \"txs\": $txids }"
}

i=0
argsArray=( "$@" )
for var in "$@"
do
    i=$(( i+1 ))
    if [[ ${var:0:1} == "-" ]];
    then
        continue
    elif [ "$var" == "getblock" ];
    then
        $BCLI "$@"
        if [ $? -ne 0 ]; then
            getblock "${argsArray[$i]}"
        fi;
        break
    else
        set -e
        $BCLI "$@"
        break
    fi
done