1 files changed, 116 insertions, 0 deletions
diff --git a/src/pybind/mgr/dashboard/plugins/pluggy.py b/src/pybind/mgr/dashboard/plugins/pluggy.py
new file mode 100644
index 000000000..53a0cf65d
--- /dev/null
+++ b/src/pybind/mgr/dashboard/plugins/pluggy.py
@@ -0,0 +1,116 @@
+# -*- coding: utf-8 -*-
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015 holger krekel (rather uses bitbucket/hpk42)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+"""\
+"""
+CAVEAT:
+This is a minimal implementation of python-pluggy (based on 0.8.0 interface:
+https://github.com/pytest-dev/pluggy/releases/tag/0.8.0).
+
+
+Despite being a widely available Python library, it does not reach all the
+distros and releases currently targeted for Ceph Nautilus:
+- CentOS/RHEL 7.5 [ ]
+- CentOS/RHEL 8 [ ]
+- Debian 8.0 [ ]
+- Debian 9.0 [ ]
+- Ubuntu 14.05 [ ]
+- Ubuntu 16.04 [X]
+
+TODO: Once this becomes available in the above distros, this file should be
+REMOVED, and the fully featured python-pluggy should be used instead.
+"""
+try:
+    from typing import DefaultDict
+except ImportError:
+    pass  # For typing only
+
+
+class HookspecMarker(object):
+    """ Dummy implementation. No spec validation. """
+
+    def __init__(self, project_name):
+        self.project_name = project_name
+
+    def __call__(self, function, *args, **kwargs):
+        """ No options supported. """
+        if any(args) or any(kwargs):
+            raise NotImplementedError(
+                "This is a minimal implementation of pluggy")
+        return function
+
+
+class HookimplMarker(object):
+    def __init__(self, project_name):
+        self.project_name = project_name
+
+    def __call__(self, function, *args, **kwargs):
+        """ No options supported."""
+        if any(args) or any(kwargs):
+            raise NotImplementedError(
+                "This is a minimal implementation of pluggy")
+        setattr(function, self.project_name + "_impl", {})
+        return function
+
+
+class _HookRelay(object):
+    """
+    Provides the PluginManager.hook.<method_name>() syntax and
+    functionality.
+    """
+
+    def __init__(self):
+        from collections import defaultdict
+        self._registry = defaultdict(list)  # type: DefaultDict[str, list]
+
+    def __getattr__(self, hook_name):
+        return lambda *args, **kwargs: [
+            hook(*args, **kwargs) for hook in self._registry[hook_name]]
+
+    def _add_hookimpl(self, hook_name, hook_method):
+        self._registry[hook_name].append(hook_method)
+
+
+class PluginManager(object):
+    def __init__(self, project_name):
+        self.project_name = project_name
+        self.__hook = _HookRelay()
+
+    @property
+    def hook(self):
+        return self.__hook
+
+    def parse_hookimpl_opts(self, plugin, name):
+        return getattr(
+            getattr(plugin, name),
+            self.project_name + "_impl",
+            None)
+
+    def add_hookspecs(self, module_or_class):
+        """ Dummy method"""
+
+    def register(self, plugin, name=None):  # pylint: disable=unused-argument
+        for attr in dir(plugin):
+            if self.parse_hookimpl_opts(plugin, attr) is not None:
+                # pylint: disable=protected-access
+                self.hook._add_hookimpl(attr, getattr(plugin, attr))