Add packaging config, freeze deps in requirements.

- This makes installation with pip possible.
- Docker builds do use the requirements.txt file to make the builds
  reproducible.
- freeze.py is used update the requirements.txt when the unpinned
  dependencies in the pyproject.toml change.

freeze.py

@@ -0,0 +1,39 @@
+"""
+Pin the dependencies given in pyproject.toml.
+"""
+
+from venv import EnvBuilder
+from shutil import rmtree
+from subprocess import check_call
+from tomllib import load
+from os import mkdir, path, remove
+
+BUILD = "build"
+REQUIREMENTS = "build/requirements.txt"
+VENV = "build/.venv"
+
+try:
+    try:
+        mkdir(BUILD, mode=0o750)
+    except FileExistsError:
+        pass
+    try:
+        mkdir(VENV, mode=0o750)
+    except FileExistsError:
+        pass
+
+    EnvBuilder().create(VENV)
+    with open("pyproject.toml", "rb") as project:
+        pyproject = load(project)
+    with open(REQUIREMENTS, "w") as requirements:
+        requirements.write("\n".join(pyproject["project"]["dependencies"]))
+    check_call([VENV + "/bin/python", "-m", "ensurepip"])
+    check_call([VENV + "/bin/pip3", "install", "-r", REQUIREMENTS])
+    with open("requirements.txt", "w") as requirements:
+        check_call([VENV + "/bin/pip3", "freeze", "-r", REQUIREMENTS],
+                   stdout=requirements)
+finally:
+    if path.isdir(VENV):
+        rmtree(VENV)
+    if path.exists(REQUIREMENTS):
+        remove(REQUIREMENTS)

pyproject.toml

@@ -0,0 +1,50 @@
+[build-system]
+requires = ["setuptools >= 61.0", "setuptools-scm"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "devicepasswords"
+authors = [
+    {name = "Varbin the Fox"}
+]
+description = "Simple device password management to replace regular password for systems not capable of single sign-on. "
+readme = "README.md"
+requires-python = ">=3.11"
+keywords = ["python", "docker", "flask", "oidc", "single-sign-on", "devicepassword"]
+license = {text = "MPL-2.0"}
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Framework :: Flask",
+    "Framework :: aiohttp",
+    "Intended Audience :: System Administrators",
+    "License :: OSI Approved :: Mozilla Public License 2.0 (MPL 2.0)",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Topic :: Internet :: WWW/HTTP :: WSGI :: Application",
+    "Topic :: Security",
+    "Topic :: System :: Systems Administration :: Authentication/Directory",
+]
+dependencies = [
+    "flask >= 3.0.0",
+    "flask-sqlalchemy",
+    "flask-alembic",
+    "python-jose[cryptography]",
+    "requests",
+    "gevent>1.4",
+    "flask-session",
+    # Password hashing
+    "passlib",
+    "argon2-cffi",
+    # Database drivers
+    "psycopg2-binary",
+    "pymysql",
+    "pymssql",
+    # Server for production
+    "gunicorn",
+]
+dynamic = ["version"]
+
+[tool.setuptools]
+packages = ["devicepasswords"]

setup.py

@@ -0,0 +1,10 @@
+"""
+Setup script for the devicepasswords application.
+
+With modern packaging tools,
+this file is not really required anymore.
+"""
+
+from setuptools import setup
+
+setup()