I have gotten some help on the irc channel but as yet no solution. I am having trouble connecting a php-apache container to a mysql container. The frustrating part is that I got it all working and then I brought down and brought back up the containers and it stopped working. I can attach to the mysql contianer and run mysql commands locally but trying to do it from the php-apache container times out. Specifically (HY000/2002): Connection timed out. I can ping the mysql container from the host OS. My docker-compose.yml and Dockerfile are here https://gist.github.com/smaction/bdcc3537150d2a9fa62609481da35394 . The images are both the official PHP an Mysql images. My host OS is Ubuntu 18.04.