So on my latest Capistrano deploy to MomentumStockScans.com, I received the following error:

$ sudo docker-compose up -d
sudo: unable to resolve host ip-172-30-0-194
Creating network "20170713014600_default" with the default driver
ERROR: could not find an available, non-overlapping IPv4 address pool among the defaults to assign to the network

Turns out every time I was running docker-compose it created a new bridge network, and there's a limit of 31 networks on the system!

When I did docker network ls, it gave me a whole list of networks it created. One for each deploy. I cleared them using

$ sudo docker network prune

Everything was fine! Will add the above command to my Capistrano deploy script.