Docker: how to connect two bridges
As you know after Docker 1.9 we can create bridges to connect containers.
I have created two custom bridges: bridge A
172.18.0.1 and bridge B
Now I have a container1 on bridge A, and a container2 on bridge B called “mailServer”.
The container1 needs to reach container2 by a DNS, how should I do this? Because they are on different bridges so they cannot talk to each other. Do I need a router and can I achieve this by Docker?
This is a new feature of Docker and I didn’t find much information. Thanks.
3 Solutions collect form web for “Docker: how to connect two bridges”
You can try making use of the veth peer so that you can connect two bridges. Make sure you are rename and names respectively with the one you configured.
ip link add veth0 type veth peer name veth1 ifconfig veth0 up ifconfig veth1 up brctl addif <D1-A-Bridge> veth0 brctl addif <D2-A-Bridge> veth1
To connect container2 to container1 you can also connect it to bridgeB
$ docker network connect bridgeB container1
This will allow container1 to connect to container2 by IP address, DNS names would still have to be updated manually afaik.
More information in the Docker networking guide here.
If you want to connect two bridges, you can use a pair of
patch ports with open v-switch . The follow example creates bridges br0 and br1, adds eth0 and tap0 to br0, adds tap1 to br1, and then connects br0 and br1 with a pair of patch ports.
ovs-vsctl add-br br0 ovs-vsctl add-port br0 eth0 ovs-vsctl add-port br0 tap0 ovs-vsctl add-br br1 ovs-vsctl add-port br1 tap1 ovs-vsctl \ -- add-port br0 patch0 \ -- set interface patch0 type=patch options:peer=patch1 \ -- add-port br1 patch1 \ -- set interface patch1 type=patch options:peer=patch0