To quickly see on your Mac why your Redis cannot be connected to or why Docker cannot run localhost because port 80 is taken you can use the following on MacOS
sudo lsof -iTCP -sTCP:LISTEN -n -P
To quickly check just a port use
sudo lsof -i ':80'
or check Redis port and see its host do
sudo lsof -i ':6379'
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
redis-ser 5032 jasperfrumau 6u IPv4 0xd5d308d04c18512f 0t0 TCP localhost:6379 (LISTEN)
redis-ser 5032 jasperfrumau 7u IPv6 0xd5d308d9e6010627 0t0 TCP localhost:6379 (LISTEN)