docker: how to get veth bridge interface pair easily?
bridge, docker, networking
Solution
Here's a variation on the ethtool trick mentioned above, without actually using ethtool:
function veth_interface_for_container() {
# Get the process ID for the container named ${1}:
local pid=$(docker inspect -f '{{.State.Pid}}' "${1}")
# Make the container's network namespace available to the ip-netns command:
mkdir -p /var/run/netns
ln -sf /proc/$pid/ns/net "/var/run/netns/${1}"
# Get the interface index of the container's eth0:
local index=$(ip netns exec "${1}" ip link show eth0 | head -n1 | sed s/:.*//)
# Increment the index to determine the veth index, which we assume is
# always one greater than the container's index:
let index=index+1
# Write the name of the veth interface to stdout:
ip link show | grep "^${index}:" | sed "s/${index}: \(.*\):.*/\1/"
# Clean up the netns symlink, since we don't need it anymore
rm -f "/var/run/netns/${1}"
}
Problem
i have 2 containers by docker, and bridge like this: ``` # docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES ef99087167cb images.docker.sae.sina.com.cn/ubuntu:latest /bin/bash -c /home/c 2 days ago Up 21 minutes 0.0.0.0:49240->22223/tcp night_leve3 c8a7b18ec20d images.docker.sae.sina.com.cn/ubuntu:latest /bin/bash -c /home/c 2 days ago Up 54 minutes 0.0.0.0:49239->22223/tcp night_leve2 #brctl show cbr0 bridge name bridge id STP enabled interfaces docker0 8000.72b675c52895 no vethRQOy1I vethjKYWka ``` How can i get which container match `veth*` ? `ef99 => vethRQOy1I or ef99 => vethjKYWka` //---------------------------------------------------------- I know it works by `ethtool`, but is there any better way?