Revert "Revert "Add pyproject.toml file (#11305)" (#11467)"

This reverts commit 0462336.

datadog_checks_downloader/pyproject.toml

@@ -0,0 +1,62 @@
+[build-system]
+requires = [
+    "hatchling>=0.11.2",
+    "setuptools; python_version < '3.0'",
+]
+build-backend = "hatchling.build"
+
+[project]
+name = "datadog-checks-downloader"
+description = "The Datadog Checks Downloader"
+readme = "README.md"
+license = "BSD-3-Clause"
+keywords = [
+    "datadog",
+    "datadog agent",
+    "datadog check",
+]
+authors = [
+    { name = "Datadog", email = "packages@datadoghq.com" },
+]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "Intended Audience :: System Administrators",
+    "License :: OSI Approved :: BSD License",
+    "Programming Language :: Python :: 2.7",
+    "Programming Language :: Python :: 3.8",
+    "Topic :: System :: Monitoring",
+]
+dynamic = [
+    "version",
+]
+
+[project.optional-dependencies]
+deps = [
+    "in-toto==1.0.1",
+    "securesystemslib[crypto,pynacl]==0.20.1",
+    "tuf==0.17.0; python_version < '3.0'",
+    "tuf==0.19.0; python_version > '3.0'",
+]
+
+[project.urls]
+Source = "https://github.com/DataDog/integrations-core"
+
+[tool.hatch.version]
+path = "datadog_checks/downloader/__about__.py"
+
+[tool.hatch.build.targets.sdist]
+include = [
+    "/datadog_checks",
+    "/tests",
+    "/requirements-dev.txt",
+    "/tox.ini",
+]
+
+[tool.hatch.build.targets.wheel]
+include = [
+    "/datadog_checks",
+]
+dev-mode-dirs = [
+    ".",
+]

datadog_checks_downloader/setup.py

@@ -27,6 +27,21 @@ def get_dependencies():
         return f.readlines()
 
 
+def parse_pyproject_array(name):
+    import os
+    import re
+    from ast import literal_eval
+
+    pattern = r'^{} = (\[.+?\])$'.format(name)
+
+    with open(os.path.join(HERE, 'pyproject.toml'), 'r', encoding='utf-8') as f:
+        # Windows \r\n prevents match
+        contents = '\n'.join(line.rstrip() for line in f.readlines())
+
+    array = re.search(pattern, contents, flags=re.MULTILINE | re.DOTALL).group(1)
+    return literal_eval(array)
+
+
 setup(
     # Version should always match one from an agent release
     version=ABOUT["__version__"],
@@ -52,7 +67,7 @@ def get_dependencies():
     ],
     packages=['datadog_checks.downloader'],
     # Run-time dependencies
-    extras_require={'deps': get_dependencies()},
+    extras_require={'deps': parse_pyproject_array('deps')},
     # NOTE: Copy over TUF directories, and root metadata.
     package_data={
         'datadog_checks.downloader': [

datadog_checks_downloader/tox.ini

@@ -11,9 +11,9 @@ envdir =
     py38: {toxworkdir}/py38
 dd_check_style = true
 usedevelop = true
+extras = deps
 deps =
   -e../datadog_checks_base[deps]
   -rrequirements-dev.txt
 commands =
-  pip install -r requirements.in
   pytest -v {posargs} --capture=no --log-cli-level=debug