I'm perfectly happy with the IP range that docker is giving me by default 176.17.x.x
, so I don't need to create a new bridge, I just want to give my containers a static address within that range so I can point client browsers to it directly.
I tried using
RUN echo "auto eth0" >> /etc/network/interfaces
RUN echo "iface eth0 inet static" >> /etc/network/interfaces
RUN echo "address 176.17.0.250" >> /etc/network/interfaces
RUN echo "netmask 255.255.0.0" >> /etc/network/interfaces
RUN ifdown eth0
RUN ifup eth0
from a Dockerfile, and it properly populated the interfaces file, but the interface itself didn't change. In fact, running ifup eth0 within the container gets this error:
RTNETLINK answers: Operation not permitted Failed to bring up eth0
This worked for me:
Explained:
--cap-add=NET_ADMIN
have rights for administering the net (i.e. for the/sbin/ip
command)myimages/image1
image for the container/bin/sh -c "/sbin/ip addr add 172.17.0.8 dev eth0 ; bash"
Inside the container runip addr add 172.17.0.8 dev eth0
to add a new ip address 172.17.0.8 to this container (caution: do use a free ip address now and in the future). Then run bash, just to not have the container automatically stopped.Bonus:
My target scene: setup a distributed app with containers playing different roles in the dist-app. A "conductor container" is able to run docker commands by itself (inside) so to start and stop containers as needed. Each container is configured to know where to connect to access a particular role/container in the dist-app (so the set of ip's for each role must be known by each partner).
To do this:
image created with this Dockerfile
image build command:
container run command:
First (not absolutely necessary) add entries to
/etc/hosts
to locate partners by ip or name (option--add-host
)Second (obviously required) assign a ip to the running container (use
/sbin/ip
in it)br0
)docker
with:-b=br0
& with pipework (
192.168.1.1
below being thedefault gateway
ip address):Edit: do not start with
--net=none
: this closes container ports.See further notes
I have already answered this here https://stackoverflow.com/a/35359185/4094678 but I see now that this question is actually older then the aforementioned one, so I'll copy the answer as well:
Easy with Docker version 1.10.1, build 9e83765.
First you need to create you own docker network (mynet123)
than simply run the image (I'll take ubuntu as example)
then in ubuntu shell
Additionally you could use
--hostname
to specify a hostname--add-host
to add more entries to/etc/hosts
Docs (and why you need to create a network) at https://docs.docker.com/engine/reference/commandline/network_create/
I discovered that
--net=host
might not always be the best option, as it might allow users to shut down the host from the container! In any case, it turns out that the reason I couldn't properly do it from inside was because network configuration was designed to be restricted to sessions that begun with the--privileged=true
argument.pipework also great, but If you can use hostname other than ip then you can try this script
You just need to run this command everytime you boot up your docker labs You can find my scripts with additional function here dockerip
I understood that you are not looking at multi-host networking of containers at this stage, but I believe you are likely to need it soon. Weave would allow you to first define multiple container networks on one host, and then potentially move some containers to another host without loosing the static IP you have assigned to it.