Creating network "flask-api" with the default driver
ERROR: could not find an available, non-overlapping IPv4 address pool among the defaults to assign to the network
docker network create “flask-api” –subnet 121.142.218.223/24
해결방법
docker network create abcd --subnet 172.17.0.0/16
docker network create flask-api --subnet 172.17.0.0/16