From 8f909b3d81fa21af91e1e96a85168e7643faf9d3 Mon Sep 17 00:00:00 2001
From: Steve Kowalik <steven@wedontsleep.org>
Date: Wed, 12 Apr 2023 13:57:02 +1000
Subject: [PATCH] Use importlib.metadata rather than pkg_resources

pkg_resources is a deprecated API, and a rather heavyweight one. Since
Python 3.8, the standard library has included importlib.metadata, which
can do the same functionality we're looking for here. Since we continue
to support older versions of Python, fallback to importlib_metadata if
required.
---
 requirements.txt                |  1 +
 setup.py                        |  1 +
 src/scitokens/utils/keycache.py | 11 ++++++++---
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/requirements.txt b/requirements.txt
index d767b78..4e260fe 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 cryptography
+importlib_metadata;python_version<'3.8'
 PyJWT>=2.2.0
diff --git a/setup.py b/setup.py
index ad046e6..0ad28c7 100644
--- a/setup.py
+++ b/setup.py
@@ -66,6 +66,7 @@ def find_version(path, varname="__version__"):
     install_requires=[
         'cryptography',
         'PyJWT>=1.6.1',
+        "importlib_metadata;python_version<'3.8'",
         'setuptools'
     ],
     extras_require={
diff --git a/src/scitokens/utils/keycache.py b/src/scitokens/utils/keycache.py
index 398980f..56385f9 100644
--- a/src/scitokens/utils/keycache.py
+++ b/src/scitokens/utils/keycache.py
@@ -6,12 +6,17 @@
 import os
 import sqlite3
 import time
-import pkg_resources  # part of setuptools
 import re
 import logging
+
+try:
+    import importlib.metadata as import_meta
+except ImportError:
+    import importlib_metadata as import_meta
+
 try:
-    PKG_VERSION = pkg_resources.require("scitokens")[0].version
-except pkg_resources.DistributionNotFound as error:
+    PKG_VERSION = import_meta.version("scitokens")
+except import_meta.PackageNotFoundError:
     # During testing, scitokens won't be installed, so requiring it will fail
     # Instead, fake it
     PKG_VERSION = '1.0.0'