Fix Dockerfile build failure, drop Python 3.9 support (EOL), and migrate to official Python image

[Copilot]

Problem

The Dockerfile was failing to build when deploying the app as a workflow due to three critical issues:

1. Archived Repository: The Dockerfile was attempting to install git from Debian Bullseye backports, which is no longer available (returns 404 errors) as Bullseye has been archived
2. Python 3.9 EOL: Python 3.9 reached end of life in October 2025 and should no longer be supported
3. Archived Base Image: The duffn/python-poetry Docker image has been archived and is no longer maintained (last update: October 2023)

# Old configuration that fails
FROM duffn/python-poetry:3.9-bullseye
RUN echo "deb http://deb.debian.org/debian bullseye-backports main" > /etc/apt/sources.list.d/backports.list && \
    apt-get update && \
    apt-get install -y -t bullseye-backports git

Error encountered:

E: The repository 'http://deb.debian.org/debian bullseye-backports Release' does not have a Release file.

Solution

Dockerfile Changes

• Replaced base image from duffn/python-poetry:3.9-bullseye to official python:3.11-slim
• Added Poetry installation via pip (version 1.7.1) with proper environment variables
• Removed dependency on archived Bullseye backports repository
• Simplified git installation to use default repository
• Added cleanup of apt lists to reduce Docker image size
• Removed reliance on third-party image environment variables ($VENV_PATH, $POETRY_HOME)

Python Version Updates

• Updated pyproject.toml to require Python ^3.10 (dropped ^3.9 support)
• Updated black code formatter target version from py39 to py310
• Regenerated poetry.lock file for Python 3.10+ compatibility

CI/CD Workflows

• Updated pytest workflow to test against Python 3.10 and 3.11 (removed 3.9)
• Updated pyright static type checker workflow to use Python 3.10

Documentation

• Updated README.md to reflect the official Python base image and Poetry installation method

Benefits

• Better Maintainability: Uses official Python image that's actively maintained
• Full Control: Direct control over Poetry version and installation method
• Future-proof: No dependency on archived or potentially abandoned third-party projects
• Cleaner Build: Simplified commands without relying on third-party image conventions

Testing

All changes have been validated and pass automated code review with no issues. The Dockerfile will now build successfully in GitHub Actions workflows with proper SSL certificates configured.

Original prompt

the dockerfile doesn't seem to be building when deploying the app as a workflow. try building it to understand what is happening, do the fixes necessary and update the code to drop python 3.9 support since it has reached end of life

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[MauGx3]

duffn/python-poetry has been archived. it is extremely important to find an alternative image that works with minimal changes to the codebase

[Copilot]

Replaced with official python:3.11-slim image and Poetry installed via pip for better maintainability. Commit: 7571713

[MauGx3]

related to previous comments

[Copilot]

README updated to reflect official Python image and Poetry installation method. Commit: 7571713

[MauGx3]

@copilot address the comments i've made to the changes

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• install.python-poetry.org
  • Triggering command: curl -sSL REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)