dockerveth

Show which docker containers are attached to which veth interfaces on your server.

Example

[root@dockervisor-1 ~]# dockerveth
CONTAINER ID	VETH       	NAMES
60d27ce962ff	vethe353e93	hopeful_bhaskara
d07a2979e69a	vethe4c3cee	silly_meitner
1e8656e195ba	veth1ce04be	thirsty_meitner

Motivation

When I'm tracking down a problem in production, I'll typically wind up on a Docker server and see that my problems are coming from one veth interface or another. But making the leap from veth ID to container ID can be tricky. Folks on the internet suggest that you run some commands in bash inside your container, which is OK if your container has bash. Sometimes I'm working on Go containers that are just a single binary and don't even have a command-line interface to attach to.

This script provides a nice, nearly-programmatic (only a small amount of string manipulation) way to get a map of veth IDs to container IDs.

Requirements

Linux
Docker
The ip commands (you know, the ones that superseded ifconfig?)
A POSIX compliant shell at /bin/sh

Installation

Download dockerveth.sh and save it wherever you like.
Make sure dockerveth.sh is executable:

chmod +x dockerveth.sh

Symlink dockerveth.sh to a program directory. Example:

# From the directory containing dockerveth.sh:
ln -s "$(pwd)/dockerveth.sh" /usr/local/bin/dockerveth

Usage

dockerveth.sh - Show which docker containers are attached to which
`veth` interfaces.

Usage: dockerveth.sh [DOCKER PS OPTIONS] | [-h, --help]

Options:
    DOCKER PS OPTIONS   Pass any valid `docker ps` flags. Do not pass
                        a '--format' flag.
    -h, --help          Show this help and exit.

Output:
    If stdout is not a tty, column headers are omitted.