[TODO] investigate switching from pipenv + setuptools to poetry

[ITProKyle]

Summary

poetry is a single tool that manages virtual environments, dependencies, packaging, and publishing.

When compared directly with pipenv, poetry is significantly faster when handling dependencies. This is a noticeable issue with this project as the dev dependencies can take quite some time to sync. It also supports the new python standard pyproject.toml.

Considerations

• How will this impact our Pyinstaller builds?
• How will this impact the ability to install Runway from GitHub? (pip, pipenv, poetry)
• How will it impact the developers/maintainers? (other than requiring a different tool to be installed)

[ITProKyle]

I spent a bit of time working through this and here are my findings.

Pros

• faster dependency resolution (poetry>=1.1)
• when adding a dependency, it has a lot more logic around factoring compatibility. it includes the project dependencies, their dependencies, and the python version requirements of all involved. when something is not compatible, it provides great information as to why it's not so that it can be resolved.
• single tool for build and publish
• single configuration file (pyproject.toml vs setup.py + setup.cfg
• poetry would be able to install runway from github if it was a poetry project (see cons for details)
• dependency version per python version (see zipp, pydocstyle, pylint, or pytest below)

Cons

• unable to have dynamic versioning based on vcs tags (feature support is slated for v1.2 [Discussion] Poetry to provide a decent hook-based plugin system python-poetry/poetry#693, WIP - Plugin system python-poetry/poetry#1237)
• alone the same lines, poetry is currently unable to install runway from github because of our use of vcs versioning. but, this is because it does not run the setup.py file (by design)

I stopped investigation after running into the vcs versioning issue.

Conclusion (for now)

In its current state, even though I really want the performance improvement and file consolidations, I don't feel that it would be advantageous for us to move to poetry. Personally, I don't want to give up vcs versioning as it makes building/releasing pre-release build and official releases much easier in our current system.

Once the plugin system is added to poetry, this issue should be revisited as vcs versioning should then be possible.

Resulting pyproject.toml

[tool.poetry]
name = "runway"
# version can't be set from git automatically yet
# support for something like this is slated for v1.2 - https://github.com/python-poetry/poetry/pull/1237
version = "1.11.0-dev0"
description = "Simplify infrastructure/app testing/deployment"
authors = ["Onica Group LLC <[email protected]>"]
license = "Apache-2.0"
readme = "README.md"
homepage = "https://docs.onica.com/projects/runway"
repository = "https://github.com/onicagroup/runway"
documentation = "https://docs.onica.com/projects/runway"
keywords = ["cli"]
classifiers = [
    "Intended Audience :: Developers",
    "Topic :: Utilities",
    "Natural Language :: English",
    "Operating System :: OS Independent",
    "Programming Language :: Python :: 2",
    "Programming Language :: Python :: 2.7",
    "Programming Language :: Python :: 3",
    "Programming Language :: Python :: 3.6",
    "Programming Language :: Python :: 3.7",
]
packages = [
    { include = "runway" }
]

[tool.poetry.dependencies]
python = ">=2.7 !=3.0.* !=3.1.* !=3.2.* !=3.3.* !=3.4.* <4"  # based on other dependency reqs

awacs = "*"
awscli = ">=1.16.308 <2.0"  # awscli included for embedded hooks and aws subcommand
"backports.tempfile" = { version = "*", python = "<3.2" }
boto3 = "^1.9.111"
botocore = ">=1.12.111"  # matching awscli/boto3 requirement
cfn_flip = "^1.2.1"  # 1.2.1+ require PyYAML 4.1+
cfn-lint = "*"
click = "^7.1"
coloredlogs = "*"
docker = "*"
formic2 = "*"  # inherited from stacker 1.7.0 requirements
future = "*"
gitpython = "*"
importlib-metadata = { version = "*", python = "<3.8" }
jinja2 = "^2.7"  # inherited from stacker 1.7.0 requirements
packaging = "*"  # component of setuptools needed for version compare
pyhcl = "~0.4"
pyOpenSSL = "*"    # for embedded hook & associated script usage
PyYAML = ">=4.1 <5.3"  # match awscli top-end
requests = "*"
schematics = "~2.0.1"  # inherited from stacker 1.7.0 requirements
Send2Trash = "*"
six = "^1.13"
troposphere = "^2.4"
typing = { version = "*", python = "<3.5" }
# botocore pins its urllib3 dependency like this, so we need to do the
# same to ensure v1.25+ isn't pulled in by pip
urllib3 = ">=1.20 <1.25"
yamllint = "*"
zipp = [  # dependency of importlib-metadata, dependency of pytest, cfn-lint, & others
    { version = "*", python = "^3.6" },
    { version = "^1", python = "<3.6" }  # 2.0.0 drops support for python 3.5
]
zgitignore = "*"  # for embedded hooks

[tool.poetry.dev-dependencies]
dunamai = {version = "^1.3.0", python = "^3.5"}
flake8 = "^3.8.3"
flake8-docstrings = "^1.5.0"
isort = "^4.3.21"  # restricted by pylint
mock = "~=3.0.5"  # TODO remove when dropping python 2
moto = "^1.3.14"
pep8-naming = "^0.11.1"
py = "1.9.0"  # TODO replaces uses with pathlib
pydocstyle = [
    { version = "^5.0.0", python = "^3.5" },
    { version = "^3.0.0", python = "^2.7" }  # 4.0.0 drops support for python 2
]
PyInstaller = "3.5"
pylint = [
    { version = "^2.5.3", python = "^3.5" },
    { version = "^1.9.5", python = "^2.7" }
]
pytest = [
    { version = "^6.0.1", python = "^3.5" },
    { version = "^4.6.11", python = "^2.7" }  # last version that supports 2.7
]
pytest-cov = "^2.10.0"
testfixtures = "^6.14.1"

[tool.poetry.scripts]
runway = "runway._cli.main:cli"

[build-system]
requires = ["poetry-core>=1.0.0b2"]
build-backend = "poetry.core.masonry.api"