Docker parallel build failing. Anyone?

[bradrydzewski]

@sherry-ummen

then it sometimes works and sometimes not? I mean in our case about 70% times it works but not for the rest.

this is because it is a race condition. If two docker-in-docker daemons try to set iptables rules at the exact same time it will fail. It they try to update iptables, but one updates a few hundred milliseconds before the other, it would succeed.