fix: remove pkg_resources dependency on python 3

Fixes #232
Signed-off-by: Martin Styk <mart.styk@gmail.com>

Author: StykMartin

Client/src/bkr/__init__.py

@@ -1,6 +1,11 @@
 # See http://peak.telecommunity.com/DevCenter/setuptools#namespace-packages
-try:
-    __import__('pkg_resources').declare_namespace(__name__)
-except ImportError:
+import sys
+if sys.version_info[0] >= 3:
     from pkgutil import extend_path
     __path__ = extend_path(__path__, __name__)
+else:
+    try:
+        __import__('pkg_resources').declare_namespace(__name__)
+    except ImportError:
+        from pkgutil import extend_path
+        __path__ = extend_path(__path__, __name__)

Client/src/bkr/client/__init__.py

@@ -14,9 +14,10 @@
 import xml.dom.minidom
 from optparse import OptionGroup
 
-import pkg_resources
 from six.moves.urllib_parse import urljoin
 
+from bkr.common.resources import resource_filename
+
 from bkr.client.command import Command
 from bkr.common.pyconfig import PyConfigParser
 
@@ -53,7 +54,7 @@ def host_filter_presets():
 
     _host_filter_presets = {}
     config_files = (
-            sorted(glob.glob(pkg_resources.resource_filename('bkr.client', 'host-filters/*.conf')))
+            sorted(glob.glob(resource_filename('bkr.client', 'host-filters/*.conf')))
             + sorted(glob.glob('/etc/beaker/host-filters/*.conf')))
     user_config_file = os.path.expanduser('~/.beaker_client/host-filter')
     if os.path.exists(user_config_file):

Client/src/bkr/client/commands/cmd_job_submit.py

@@ -106,9 +106,10 @@
 import xml.dom.minidom
 
 import lxml.etree
-import pkg_resources
 import six
 
+from bkr.common.resources import resource_stream
+
 from bkr.client import BeakerCommand
 from bkr.client.convert import Convert
 from bkr.client.task_watcher import *
@@ -211,7 +212,7 @@ def run(self, *args, **kwargs):
         if not jobs:
             jobs = ['-'] # read one job from stdin by default
         job_schema = lxml.etree.RelaxNG(lxml.etree.parse(
-                pkg_resources.resource_stream('bkr.common', 'schema/beaker-job.rng')))
+                resource_stream('bkr.common', 'schema/beaker-job.rng')))
 
         self.set_hub(**kwargs)
         submitted_jobs = []

Client/src/bkr/client/main.py

@@ -14,9 +14,10 @@
 from optparse import SUPPRESS_HELP
 
 import gssapi
-import pkg_resources
 from six.moves.xmlrpc_client import Fault
 
+from bkr.common.resources import iter_entry_points
+
 from bkr.client.command import BeakerClientConfigurationError
 from bkr.client.command import ClientCommandContainer
 from bkr.client.command import CommandOptionParser
@@ -41,7 +42,7 @@ def register_all(cls):
         # Load subcommands from setuptools entry points in the bkr.client.commands
         # group. This is the new, preferred way for other packages to provide their
         # own bkr subcommands.
-        for entrypoint in pkg_resources.iter_entry_points('bkr.client.commands'):
+        for entrypoint in iter_entry_points('bkr.client.commands'):
             cls.register_plugin(entrypoint.load(), name=entrypoint.name)
 
 

Common/bkr/__init__.py

@@ -1,6 +1,11 @@
 # See http://peak.telecommunity.com/DevCenter/setuptools#namespace-packages
-try:
-    __import__('pkg_resources').declare_namespace(__name__)
-except ImportError:
+import sys
+if sys.version_info[0] >= 3:
     from pkgutil import extend_path
     __path__ = extend_path(__path__, __name__)
+else:
+    try:
+        __import__('pkg_resources').declare_namespace(__name__)
+    except ImportError:
+        from pkgutil import extend_path
+        __path__ = extend_path(__path__, __name__)

Common/bkr/common/resources.py

@@ -0,0 +1,45 @@
+# Copyright Contributors to the Beaker project.
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import sys
+
+if sys.version_info[0] == 3 and sys.version_info < (3, 9):
+    raise ImportError("Python 3.9+ is required; found %d.%d" % sys.version_info[:2])
+
+if sys.version_info >= (3, 9):
+    import importlib.resources
+    import importlib.metadata
+
+    def resource_stream(package, resource_name):
+        return importlib.resources.files(package).joinpath(resource_name).open("rb")
+
+    def resource_filename(package, resource_name):
+        return str(importlib.resources.files(package).joinpath(resource_name))
+
+    def resource_string(package, resource_name):
+        return importlib.resources.files(package).joinpath(resource_name).read_bytes()
+
+    def resource_listdir(package, resource_name):
+        return [
+            item.name
+            for item in importlib.resources.files(package)
+            .joinpath(resource_name)
+            .iterdir()
+        ]
+
+    def resource_exists(package, resource_name):
+        traversable = importlib.resources.files(package).joinpath(resource_name)
+        return traversable.is_file() or traversable.is_dir()
+
+    def iter_entry_points(group):
+        return importlib.metadata.entry_points(group=group)
+
+else:
+    from pkg_resources import (
+        resource_stream,
+        resource_filename,
+        resource_string,
+        resource_listdir,
+        resource_exists,
+        iter_entry_points,
+    )

Common/bkr/common/test_resources.py

@@ -0,0 +1,70 @@
+# Copyright Contributors to the Beaker project.
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import unittest
+
+from bkr.common.resources import (
+    resource_stream,
+    resource_filename,
+    resource_string,
+    resource_listdir,
+    resource_exists,
+    iter_entry_points,
+)
+
+
+class ResourceStreamTest(unittest.TestCase):
+    def test_resource_stream_returns_readable_file_object(self):
+        f = resource_stream("bkr.common", "schema/beaker-job.rng")
+        try:
+            data = f.read()
+            self.assertIsInstance(data, bytes)
+            self.assertGreater(len(data), 0)
+            self.assertIn(b"<grammar", data)
+        finally:
+            f.close()
+
+
+class ResourceFilenameTest(unittest.TestCase):
+    def test_resource_filename_returns_valid_path(self):
+        import os
+
+        path = resource_filename("bkr.common", "schema/beaker-job.rng")
+        self.assertIsInstance(path, str)
+        self.assertTrue(os.path.isfile(path), "Path does not exist: %s" % path)
+
+
+class ResourceStringTest(unittest.TestCase):
+    def test_resource_string_returns_bytes(self):
+        data = resource_string("bkr.common", "schema/beaker-job.rng")
+        self.assertIsInstance(data, bytes)
+        self.assertGreater(len(data), 0)
+        self.assertIn(b"<grammar", data)
+
+
+class ResourceListdirTest(unittest.TestCase):
+    def test_resource_listdir_returns_list(self):
+        entries = resource_listdir("bkr.common", "schema")
+        self.assertIsInstance(entries, list)
+        self.assertIn("beaker-job.rng", entries)
+        self.assertIn("beaker-task.rng", entries)
+
+
+class ResourceExistsTest(unittest.TestCase):
+    def test_resource_exists_true(self):
+        self.assertTrue(resource_exists("bkr.common", "schema/beaker-job.rng"))
+
+    def test_resource_exists_false(self):
+        self.assertFalse(resource_exists("bkr.common", "schema/nonexistent.xyz"))
+
+
+class IterEntryPointsTest(unittest.TestCase):
+    def test_iter_entry_points_returns_iterable(self):
+        eps = iter_entry_points("console_scripts")
+        result = list(eps)
+        self.assertIsInstance(result, list)
+
+    def test_iter_entry_points_empty_group(self):
+        eps = iter_entry_points("nonexistent.group.12345")
+        result = list(eps)
+        self.assertEqual(result, [])

Common/bkr/common/test_schema.py

@@ -5,9 +5,10 @@
 # (at your option) any later version.
 
 import unittest
-import pkg_resources
 import lxml.etree
 
+from bkr.common.resources import resource_stream
+
 class SchemaTestBase(unittest.TestCase):
 
     schema_doc = None # filled by setUpClass
@@ -26,7 +27,7 @@ class TaskSchemaTest(SchemaTestBase):
 
     @classmethod
     def setUpClass(cls):
-        cls.schema_doc = lxml.etree.parse(pkg_resources.resource_stream(
+        cls.schema_doc = lxml.etree.parse(resource_stream(
         'bkr.common', 'schema/beaker-task.rng'))
 
     def test_minimal_task(self):
@@ -86,7 +87,7 @@ class JobSchemaTest(SchemaTestBase):
 
     @classmethod
     def setUpClass(cls):
-        cls.schema_doc = lxml.etree.parse(pkg_resources.resource_stream(
+        cls.schema_doc = lxml.etree.parse(resource_stream(
             'bkr.common', 'schema/beaker-job.rng'))
 
     def test_minimal_job(self):