I reached my Googling limit on figuring this out.
Ubuntu on 20.04.04
Docker version 20.10.7, build 20.10.7-0 ubuntu5~20.04.2
My machine has two NIC cards, an internal and external one. For some reason my docker containers can’t reach any outside host.
Example:
docker-compose run --rm api curl https://www.google.com
curl: (7) Failed to connect to wwwdotgoogledotcom port 443: No route to host
I can curl google.com no problem on the host machine. If I disable the internal NIC card and reboot the machine then the same command can reach google no problem. So something about having the 2nd NIC card on the internal IP running causes the docker container to not be able to find a route to host.
I have two other Ubuntu boxes in the same configuration (provisioned by ansible) the only notable difference is just different IP addresses (obviously) and they might be on 20.04.03.