core-lightning/tools/docker-entrypoint.sh

#!/usr/bin/env bash

: "${EXPOSE_TCP:=false}"

if [ "$EXPOSE_TCP" == "true" ]; then
    set -m
    lightningd "$@" &

    echo "C-Lightning starting"
    while read -r i; do if [ "$i" = "lightning-rpc" ]; then break; fi; done \
    < <(inotifywait  -e create,open --format '%f' --quiet "$LIGHTNINGD_DATA" --monitor)
    echo "C-Lightning started"
    echo "C-Lightning started, RPC available on port $LIGHTNINGD_RPC_PORT"

    socat "TCP4-listen:$LIGHTNINGD_RPC_PORT,fork,reuseaddr" "UNIX-CONNECT:$LIGHTNINGD_DATA/lightning-rpc" &
    fg %-
else
    exec lightningd "$@"
fi