You have to run ./unionize <bridge> <container sha1> <ip address> after starting the container, but that brings up a new interface inside the container with that IP and connects it to the bridge.
This is useful for having private IPs between containers of an application, for accessing databases or similar.
I was starting with unionize as well, but the fact is that docker looks up for available IP adresses on its own.
So you can give docker -d the -b parameter and pass an existing bridge and it will go through that bridges IP space and assign IP adresses already.
Also that way the IP address shows in "docker inspect" which it doesn't with unionize.sh (i think).
The problem here is that the built-in IP Address allocator is rather stupid and doesn't even try to ping an address before assigning it.
I got it to interfere with my network heavily when it assigned my gateways IP Address to a container ;)
It'd be nice if the whole IP Address allocation was more pluggable or configurable. Right now it's some code deeply tied into the whole system (i think) and i fear i don't have the Go skills to change that myself :(
(for example, i think i would have been able to write a little bit of Go to assign IP Addresses the way i want to, if the system would be more pluggable)
http://blog.docker.io/2013/04/unionize-network-superpowers-f...
You have to run ./unionize <bridge> <container sha1> <ip address> after starting the container, but that brings up a new interface inside the container with that IP and connects it to the bridge.
This is useful for having private IPs between containers of an application, for accessing databases or similar.