Migrate to Python 3.7

[thinkh]

Goal

Update the server code to Python 3 as the support for Python 2 will end with 2020 (see countdown). Moreover, our customers urged to use Python 3 then, due to security issues.

Resources

• Official porting guide
• Python 2 to 3 converter
• If necessary: Python __future__ package "allows you to use a single, clean Python 3.x-compatible codebase to support both Python 2 and Python 3 with minimal overhead."

Current status

• phovea_server uses already the Python future library
• https://github.com/phovea/phovea_server/tree/update_dependencies

⚠ Heads up!

• We must update also Python code of repos that are using the phovea_server as dependency
• We need to inform our customers and JKU about this update

To discuss

• How to test that everything is working after the update?

To-Do's

Things that should be done after updating all repositories:

• Deprecate the Docker image caleydo/phovea_python, since we are using the official Docker image python:3.7
  • Archive the repository https://github.com/phovea/phovea_python
• Deprecate the Docker image caleydo/phovea_circleci_python, since we are using the official CircleCI Docker image python:3.7-node-browsers
  • Archive the repository https://github.com/phovea/phovea_circleci_python