Displaying Docker containers in Conky

After using Docker over a couple of months for managing a development environment locally, I felt a bit tired of repeatedly checking the status of the containers several times each day. So I looked after how can I display the current status of the containers in the Conky system monitor.

It turned out that Conky doesn’t support Docker out of the box, but it is customizable with its exec-like commands. So I started looking after what is the best solution I can achieve from the shell. One option would be to call docker ps then alter its output using awk or sed to extract the information I want to see in Conky. But I wanted a bit cleaner approach than that, so I decided to use the Python client library to list the containers. The REST API of the docker engine provides all information one will ever need in JSON format, so picking a client library which uses the REST API seemed to be a good way to go. I chose python, because it is installed on most linux systems by default, so there is no need to install any additional language runtime or compiler to run the script.

I installed the client library with sudo pip install docker, then I put the following (executable) python script to /home/erosb/bin/docker-status.py:

#!/usr/bin/env python

import docker
client = docker.from_env()
for container in client.containers.list():
  print '{:40} {}'.format(container.attrs['Config']['Image'], container.status)

And finally I added this single line to my .conkyrc:

${exec /home/erosb/bin/docker-status.py}

Voila! It just works.

Feb 06, 2017