docker-pudb

Debug Python code within a Docker container remotely from your terminal using pudb.

Prerequisites:

• Python (versions 2.7 and 3.6+ supported)
• Docker
• pudb
• telnet client

How to do it?

Python

Just add the following line wherever you want you entry point to be:

from pudb.remote import set_trace; set_trace(term_size=(160, 40), host='0.0.0.0', port=6900)

If you wanted to debug using pudb locally you'd write instead:

import pudb; pu.db

Which is similar to how one would do it for the built-in pdb:

import pdb; pdb.set_trace()

Docker

Dockerfile

• pudb needs to be installed on the Docker image. One way to do it is adding this line to the Dockerfile:

RUN pip install pudb

• The port pudb is listening to must be open. In our example it is 6900. One way to do it is adding to your Dockerfile:

EXPOSE 6900

docker-compose

If you use docker-compose yml files the syntax is different. You should add:

ports:
    - "6900:6900"

Telnet

Mac users: If you don't have any telnet client, you can install one via Homebrew. Type brew install telnet on your terminal.

When all above is done, run the container. When the entrypoint is reached, the code execution will stop. Then you need to connect to it via a telnet client, e.g. telnet 127.0.0.1 6900. Now you will see the pudb screen and debugging can start :D

Try it out!

Clone this repository and from its root folder run:

# Optional: try it on Python 2.7 instead of 3.6+
cd python2

# Build the Docker image
docker build -t pudb-example .

# Run the container (in the background) exposing port 6900
docker run -p 6900:6900  --detach pudb-example

# Connect to pudb via telnet
telnet 127.0.0.1 6900

# Enjoy debugging and star the repo if you liked it!

Acknowledgements

• Inspiration came from this blog post. There was no code readily available to try it out, so I created this repository.
• This repository is used as a reference for this related Stack Overflow entry