how to start a docker container with multi interface? - docker

Question

I want to start a docker container with three interfaces, all these interfaces will be attached to a bridge on host.
The only solution is providing my own network plugin. the below interface will be invoked by docker daemon once container is created to configure its network:
func (d *Driver) Join(r *dknet.JoinRequest) (*dknet.JoinResponse, error)
but there is only one Endpoint object in JoinRequest struct, so the above invocation can only configure one container interface.
I don't know how to create and configure three container interfaces?

Answer 1

You need to do it multiple time
$ docker network create net1
bdc53c143e89d562761eedfd232620daf585968bc9ae022ba142d17601af6146
$ docker network create net2
d9a72a7a6ee6b61da3c6bb17e312e48888807a5a8c159fd42b6c99d219977559
$ docker network create net3
d2be9628f4fd60587d44967a5813e9ba7c730d24e953368b18d7872731a9478c
$ docker run -it --network net3 ubuntu:16.04 bash
root#cd70c7cbe367:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
90: eth0#if91: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ac:18:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.24.0.2/16 scope global eth0
valid_lft forever preferred_lft forever
Now your container is running with net3 network only. You can attach net1 and net2 as well.
$ docker network connect net1 cd70c7cbe367
$ docker network connect net2 cd70c7cbe367
After that check in container
root#cd70c7cbe367:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
90: eth0#if91: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ac:18:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.24.0.2/16 scope global eth0
valid_lft forever preferred_lft forever
92: eth1#if93: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ac:16:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.22.0.2/16 scope global eth1
valid_lft forever preferred_lft forever
94: eth2#if95: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ac:17:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.23.0.2/16 scope global eth2
valid_lft forever preferred_lft forever
PS: the ip command is missing by default in container, so i installed the iproute2 packaged to check