start.sh

#!/bin/sh

echo "Checking who is listening/bound to port 8888 ..."
netstat -tlep | grep 8888
if [ "$?" = 0 ]; then
   echo "Some process is still listening/bound to that port"
   echo "This process needs to be stopped first !"
   echo "Sleeping for 20 sec - we hope that this releases the bound TCP port 8888 ..."
   sleep 20
   echo "... sleeping finished"
else
   echo "...OK, no process is listing/bound to port 8888"
fi

echo "Starting daemon pigpiod ..."
# for pigpiod options see http://abyz.me.uk/rpi/pigpio/pigpiod.html
#  option -g will run the daemon in the foreground.
#  option -a 1 should assure that we are not using GPU memory.
#     for running on 64bit, don't include the '-a 1' flag https://github.com/zinen/docker-alpine-pigpiod/issues/17
#  option -s 10 reduces sample rate down every 10 micro seconds intead of default 5 https://github.com/joan2937/pigpio/issues/29#issuecomment-151076670
pigpiod -g -a 1 -s 10
echo "... daemon stopped unexpectedly."

# added extra logic for issue: https://github.com/janvda/balena-node-red/issues/1
echo "netstat -tlep | grep 8888"
netstat -tlep | grep 8888
echo "sleeping for 20 sec - we hope that this releases the bound TCP port 8888"
sleep 20
echo "end of sleep"
echo "netstat -tlep | grep 8888"
netstat -tlep | grep 8888

echo "... start.sh terminated"