Replace PyKerberos dependency with python-gssapi

This patch comprises the following changes:
* Replace 'kerberos' with 'gssapi'
* Modernize packaging by adding a hatch-based pyproject.toml
* Remove lingering python2 support
* Use a real kerberos realm for running tests (i.e. remove mock calls)

Future TODO:
* Support all GSSAPI backends generically and remove Kerberos references
* Add many more tests to cover all remaining branches and cases

Current test coverage report:
*********************************************************************
cmd [1] | coverage run -m pytest tests
===== test session starts =====
platform linux -- Python 3.12.3, pytest-8.1.1, pluggy-1.4.0
rootdir: ~/src/wsgi-kerberos
configfile: pyproject.toml
collected 12 items

tests/test_wsgi_kerberos.py ............ [100%]

===== 12 passed in 3.13s =====
cmd [2] | - coverage combine
Combined data file .coverage.15380.XqZVXpnx
cmd [3] | coverage report
Name                              Stmts   Miss Branch BrPart  Cover
-------------------------------------------------------------------
src/wsgi_kerberos/__init__.py         2      0      0      0   100%
src/wsgi_kerberos/middleware.py     111     21     34      6    80%
tests/__init__.py                     0      0      0      0   100%
tests/test_wsgi_kerberos.py         170      0     48      0   100%
-------------------------------------------------------------------
TOTAL                               283     21     82      6    92%
*********************************************************************

.gitignore

@@ -1,4 +1,5 @@
 *.py[cod]
+venv
 
 # C extensions
 *.so

README.rst

@@ -4,7 +4,7 @@ WSGI-Kerberos
 WSGI-Kerberos is `WSGI`_ Middleware which implements `Kerberos`_ authentication.
 It makes it easy to add Kerberos authentication to any WSGI application.
 
-Its only dependency is `python-kerberos`_ and it's been tested up to version 1.3.0
+Its only dependency is `gssapi`_ and it's been tested with v1.8.3 onwards.
 
 You can install the requirements from PyPI with ``easy_install`` or ``pip`` or
 download them by hand.

example/example_application.py

@@ -1,13 +1,15 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
+
 import logging
-from wsgi_kerberos import KerberosAuthMiddleware
 from wsgiref.simple_server import make_server
 
+from wsgi_kerberos import KerberosAuthMiddleware
+
 
 def example(environ, start_response):
     user = environ.get('REMOTE_USER', 'ANONYMOUS')
     start_response('200 OK', [('Content-Type', 'text/plain')])
-    data = "Hello {}".format(user)
+    data = f"Hello {user}"
     return [data.encode()]
 
 

pyproject.toml

@@ -0,0 +1,104 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "wsgi-kerberos"
+dynamic = ["version"]
+description = "Kerberos authentication support in WSGI Middleware"
+readme = "README.rst"
+requires-python = ">=3.8"
+license = "BSD-3-Clause"
+authors = [
+    { name="Michael Komitee", email="mkomitee@gmail.com" },
+]
+maintainers = [
+    { name="Vitaly Shupak", email="vitaly.shupak@deshaw.com" },
+]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Environment :: Web Environment",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: BSD License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+    "Topic :: Internet :: WWW/HTTP",
+    "Topic :: Internet :: WWW/HTTP :: WSGI",
+    "Topic :: Internet :: WWW/HTTP :: WSGI :: Middleware",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+]
+dependencies = [
+    "gssapi",
+]
+
+[project.urls]
+Documentation = "https://github.com/unknown/wsgi-kerberos#readme"
+Issues = "https://github.com/deshaw/wsgi-kerberos/issues"
+Homepage = "https://github.com/deshaw/wsgi-kerberos"
+
+[tool.hatch.version]
+path = "src/wsgi_kerberos/__about__.py"
+
+[tool.hatch.envs.default]
+dependencies = [
+  "coverage[toml]>=6.5",
+  "pytest",
+  "k5test",
+  "requests",
+  "requests-gssapi",
+  "wsgi-intercept",
+]
+
+[tool.hatch.envs.default.scripts]
+test = "pytest {args:tests}"
+test-cov = "coverage run -m pytest {args:tests}"
+cov-report = [
+  "- coverage combine",
+  "coverage report",
+]
+cov = [
+  "test-cov",
+  "cov-report",
+]
+
+[[tool.hatch.envs.all.matrix]]
+python = [
+    "3.8",
+    "3.9",
+    "3.10",
+    "3.11",
+    "3.12",
+]
+
+[tool.hatch.envs.types]
+dependencies = [
+  "mypy>=1.0.0",
+]
+[tool.hatch.envs.types.scripts]
+check = "mypy --install-types --non-interactive {args:src/wsgi_kerberos tests}"
+
+[tool.coverage.run]
+source_pkgs = ["wsgi_kerberos", "tests"]
+branch = true
+parallel = true
+omit = [
+  "src/wsgi_kerberos/__about__.py",
+]
+
+[tool.coverage.paths]
+wsgi_kerberos = ["src/wsgi_kerberos", "*/wsgi-kerberos/src/wsgi_kerberos"]
+tests = ["tests", "*/wsgi-kerberos/tests"]
+
+[tool.coverage.report]
+exclude_lines = [
+  "no cov",
+  "if __name__ == .__main__.:",
+  "if TYPE_CHECKING:",
+]

src/wsgi_kerberos/__about__.py

@@ -0,0 +1,4 @@
+# SPDX-FileCopyrightText: Copyright 2013-2020 D. E. Shaw & Co., L.P.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+__version__ = "1.1.0"

src/wsgi_kerberos/__init__.py

@@ -0,0 +1,10 @@
+# SPDX-FileCopyrightText: Copyright 2013-2020 D. E. Shaw & Co., L.P.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+from wsgi_kerberos.middleware import _DEFAULT_READ_MAX, KerberosAuthMiddleware
+
+__all__ = [
+    'KerberosAuthMiddleware',
+    '_DEFAULT_READ_MAX'
+]