Register plugin from entry points

src/rez/data/tests/extensions/baz/.gitignore

@@ -0,0 +1 @@
+*.egg-info

src/rez/data/tests/extensions/baz/__init__.py

@@ -0,0 +1,38 @@
+"""
+baz plugin
+"""
+
+from rez.command import Command
+
+# This attribute is optional, default behavior will be applied if not present.
+command_behavior = {
+    "hidden": False,  # (bool): default False
+    "arg_mode": None,  # (str): "passthrough", "grouped", default None
+}
+
+
+def setup_parser(parser, completions=False):
+    parser.add_argument(
+        "-m", "--message", action="store_true", help="Print message from world."
+    )
+
+
+def command(opts, parser=None, extra_arg_groups=None):
+    from baz import core
+
+    if opts.message:
+        msg = core.get_message_from_tmp()
+        print(msg)
+        return
+
+    print("Please use '-h' flag to see what you can do to this world !")
+
+
+class BazCommand(Command):
+    @classmethod
+    def name(cls):
+        return "baz"
+
+
+def register_plugin():
+    return BazCommand

src/rez/data/tests/extensions/baz/baz/__init__.py

@@ -0,0 +1,38 @@
+"""
+baz plugin
+"""
+
+from rez.command import Command
+
+# This attribute is optional, default behavior will be applied if not present.
+command_behavior = {
+    "hidden": False,  # (bool): default False
+    "arg_mode": None,  # (str): "passthrough", "grouped", default None
+}
+
+
+def setup_parser(parser, completions=False):
+    parser.add_argument(
+        "-m", "--message", action="store_true", help="Print message from world."
+    )
+
+
+def command(opts, parser=None, extra_arg_groups=None):
+    from baz import core
+
+    if opts.message:
+        msg = core.get_message_from_baz()
+        print(msg)
+        return
+
+    print("Please use '-h' flag to see what you can do to this world !")
+
+
+class BazCommand(Command):
+    @classmethod
+    def name(cls):
+        return "baz"
+
+
+def register_plugin():
+    return BazCommand

src/rez/data/tests/extensions/baz/baz/core.py

@@ -0,0 +1,4 @@
+def get_message_from_baz():
+    from rez.config import config
+    message = config.plugins.command.baz.message
+    return message

src/rez/data/tests/extensions/baz/baz/rezconfig.py

@@ -0,0 +1,3 @@
+baz = {
+    "message": "welcome to this world."
+}

src/rez/data/tests/extensions/baz/setup.py

@@ -0,0 +1,17 @@
+from __future__ import print_function, with_statement
+from setuptools import setup, find_packages
+
+
+setup(
+    name="baz",
+    version="0.1.0",
+    package_dir={
+        "baz": "baz"
+    },
+    packages=find_packages(where="."),
+    entry_points={
+        'rez.plugins': [
+            'baz_cmd = baz',
+        ]
+    }
+)

src/rez/plugin_managers.py

@@ -109,6 +109,10 @@ def register_plugin(self, plugin_name, plugin_class, plugin_module):
         self.plugin_modules[plugin_name] = plugin_module
 
     def load_plugins(self):
+        self.load_plugins_from_namespace()
+        self.load_plugins_from_entry_points()
+
+    def load_plugins_from_namespace(self):
         import pkgutil
         from importlib import import_module
         type_module_name = 'rezplugins.' + self.type_name
@@ -153,44 +157,15 @@ def load_plugins(self):
                 if config.debug("plugins"):
                     print_debug("loading %s plugin at %s: %s..."
                                 % (self.type_name, path, modname))
+
                 try:
-                    # https://github.com/AcademySoftwareFoundation/rez/pull/218
-                    # load_module will force reload the module if it's
-                    # already loaded, so check for that
                     plugin_module = sys.modules.get(modname)
                     if plugin_module is None:
                         loader = importer.find_module(modname)
                         plugin_module = loader.load_module(modname)
 
-                    elif os.path.dirname(plugin_module.__file__) != path:
-                        if config.debug("plugins"):
-                            # this should not happen but if it does, tell why.
-                            print_warning(
-                                "plugin module %s is not loaded from current "
-                                "load path but reused from previous imported "
-                                "path: %s" % (modname, plugin_module.__file__))
-
-                    if (hasattr(plugin_module, "register_plugin")
-                            and callable(plugin_module.register_plugin)):
-
-                        plugin_class = plugin_module.register_plugin()
-                        if plugin_class is not None:
-                            self.register_plugin(plugin_name,
-                                                 plugin_class,
-                                                 plugin_module)
-                        else:
-                            if config.debug("plugins"):
-                                print_warning(
-                                    "'register_plugin' function at %s: %s did "
-                                    "not return a class." % (path, modname))
-                    else:
-                        if config.debug("plugins"):
-                            print_warning(
-                                "no 'register_plugin' function at %s: %s"
-                                % (path, modname))
-
-                        # delete from sys.modules?
-
+                    self.register_plugin_module(plugin_name, plugin_module, path)
+                    self.load_config_from_plugin(plugin_module)
                 except Exception as e:
                     nameish = modname.split('.')[-1]
                     self.failed_plugins[nameish] = str(e)
@@ -201,9 +176,55 @@ def load_plugins(self):
                         traceback.print_exc(file=out)
                         print_debug(out.getvalue())
 
-            # load config
-            data, _ = _load_config_from_filepaths([os.path.join(path, "rezconfig")])
-            deep_update(self.config_data, data)
+    def load_plugins_from_entry_points(self):
+        if sys.version_info.minor >= 8:
+            from importlib.metadata import entry_points
+        else:
+            from importlib_metadata import entry_points
+
+        discovered_plugins = entry_points(group='rez.plugins')
+        for plugin in discovered_plugins:
+            plugin = plugin.load()
+            plugin_name = plugin.__name__.split('.')[-1]
+            plugin_path = os.path.dirname(plugin.__file__)
+            self.register_plugin_module(plugin_name, plugin, plugin_path)
+            self.load_config_from_plugin(plugin)
+
+    def load_config_from_plugin(self, plugin):
+        plugin_path = os.path.dirname(plugin.__file__)
+        data, _ = _load_config_from_filepaths([os.path.join(plugin_path, "rezconfig")])
+        deep_update(self.config_data, data)
+
+    def register_plugin_module(self, plugin_name, plugin_module, plugin_path):
+        module_name = plugin_module.__name__
+        if os.path.dirname(plugin_module.__file__) != plugin_path:
+            if config.debug("plugins"):
+                # this should not happen but if it does, tell why.
+                print_warning(
+                    "plugin module %s is not loaded from current "
+                    "load path but reused from previous imported "
+                    "path: %s" % (module_name, plugin_module.__file__))
+
+        if (hasattr(plugin_module, "register_plugin")
+                and callable(plugin_module.register_plugin)):
+
+            plugin_class = plugin_module.register_plugin()
+            if plugin_class is not None:
+                self.register_plugin(
+                    plugin_name,
+                    plugin_class,
+                    plugin_module
+                )
+            else:
+                if config.debug("plugins"):
+                    print_warning(
+                        "'register_plugin' function at %s: %s did "
+                        "not return a class." % (plugin_path, module_name))
+        else:
+            if config.debug("plugins"):
+                print_warning(
+                    "no 'register_plugin' function at %s: %s"
+                    % (plugin_path, module_name))
 
     def get_plugin_class(self, plugin_name):
         """Returns the class registered under the given plugin name."""

src/rez/tests/test_plugin_manager.py

@@ -5,9 +5,10 @@
 """
 test rezplugins manager behaviors
 """
-from rez.tests.util import TestBase, TempdirMixin, restore_sys_path
+from rez.tests.util import TestBase, TempdirMixin, restore_pip, restore_sys_path
 from rez.plugin_managers import plugin_manager, uncache_rezplugins_module_paths
 from rez.package_repository import package_repository_manager
+import os
 import sys
 import unittest
 
@@ -49,7 +50,7 @@ def setUp(self):
         TestBase.setUp(self)
         self._reset_plugin_manager()
 
-    def test_old_loading_style(self):
+    def test_load_plugin_from_plugin_path(self):
         """Test loading rez plugin from plugin_path"""
         self.update_settings(dict(
             plugin_path=[self.data_path("extensions", "foo")]
@@ -59,7 +60,7 @@ def test_old_loading_style(self):
             "package_repository", "cloud")
         self.assertEqual(cloud_cls.name(), "cloud")
 
-    def test_new_loading_style(self):
+    def test_load_plugin_from_python_module(self):
         """Test loading rez plugin from python modules"""
         with restore_sys_path():
             sys.path.append(self.data_path("extensions"))
@@ -68,6 +69,13 @@ def test_new_loading_style(self):
                 "package_repository", "cloud")
             self.assertEqual(cloud_cls.name(), "cloud")
 
+    def test_load_plugin_from_entry_points(self):
+        """Test loading rez plugin from setuptools entry points"""
+        with restore_pip("baz", os.path.join(self.data_path("extensions"), "baz")):
+            baz_cls = plugin_manager.get_plugin_class(
+                "command", "baz")
+            self.assertEqual(baz_cls.name(), "baz")
+
     def test_plugin_override_1(self):
         """Test plugin from plugin_path can override the default"""
         self.update_settings(dict(

src/rez/tests/util.py

@@ -303,6 +303,7 @@ def wrapper(self, *args, **kwargs):
 
 _restore_sys_path_lock = threading.Lock()
 _restore_os_environ_lock = threading.Lock()
+_restore_pip_lock = threading.Lock()
 
 
 @contextmanager
@@ -362,3 +363,15 @@ def restore_os_environ():
 
         os.environ.clear()
         os.environ.update(original)
+
+
+@contextmanager
+def restore_pip(package_name, package_path):
+    from pip._internal import main as pipmain
+
+    with _restore_pip_lock:
+        pipmain(['install', package_path])
+
+        yield True
+
+        pipmain(['uninstall', package_name, "-y"])