Move from Pipenv to Poetry

[jensneuhaus]

☝️What is it? Why do we need it?

Right now, Pipenv is not as reliable and we should switch to Poetry

💭 Implementation details

📋 Todos

• Add Poetry and remove Pipfile
• Have CircleCI work (just like we did with Pipenv, we should use the locked file there!)
• Have the deployment to Heroku still work (either use the locked file, if they support Poetry // Or have the requirement.txt file generated at CircleCI)

[jensneuhaus]

Hey @itisallgood
(cc @AntonDnepr)

what do you think would be the best practice to deal with Poetry, if Heroku does not support the lock-file out of the box?

• generate it locally (this needs to be done by every dev and could be forgotten, add problems)
• do it at CircleCI and add it to the repository somehow
• have a Github action which does the job (check if there are Poetry Github actions)
• Check if there is a Heroku buildpack supporting Poetry

Can you investigate this please, @itisallgood ?
Any ideas on this, @AntonDnepr ?

[jensneuhaus]

As addition: It seems not to be in the buildpack yet: heroku/heroku-buildpack-python#796

[AntonDnepr]

@jensneuhaus
https://python-poetry.org/docs/cli/#export

We can export poetry into requirements.txt.
The only question is where we do this.
One possible place: pre-commit hooks, though we will need to detect if there is difference between committed requirements.txt and one that was generated by the command.
There is custom buildpack for poetry:
https://github.com/moneymeets/python-poetry-buildpack
And yeah, we can search for circleci approach: add test that checks the content of requirements.txt and poetry newly generated requirements.txt. And fail build if they differ.