Initial commit

[ta/config-manager.git] / cmframework / src / cmframework / utils / cmpluginloader.py

diff --git a/cmframework/src/cmframework/utils/cmpluginloader.py b/cmframework/src/cmframework/utils/cmpluginloader.py
new file mode 100644 (file)
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+++ b/cmframework/src/cmframework/utils/cmpluginloader.py
@@ -0,0 +1,110 @@
+# Copyright 2019 Nokia
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
+import os
+import imp
+import sys
+import logging
+
+from cmframework.apis import cmerror
+
+
+class CMPluginLoader(object):
+    class LoadingFilter(object):
+        # pylint: disable=no-self-use, unused-argument
+        def is_supported(self, plugin):
+            return True
+
+    def __init__(self, plugin_location, plugin_filter=None):
+        self.location = plugin_location
+        sys.path.append(self.location)
+        self.pluginslist = []
+        self.loaded_plugin = {}
+        self.filterlist = {}
+        self.plugin_filter = plugin_filter
+
+    def find_plugin(self):
+        logging.debug('finding plugins in %s', self.location)
+        listofplugin = os.listdir(self.location)
+        for plugin in listofplugin:
+            if plugin.endswith('.py'):
+                logging.debug('Adding plugin %s', plugin)
+                self.pluginslist.append(plugin.replace(".py", ""))
+
+    def sort_plugin(self):
+        logging.debug('Sorting plugins')
+        self.pluginslist.sort()
+
+    def load_plugin(self):
+        for plugin in self.pluginslist:
+            logging.debug('Loading plugin %s', plugin)
+            fp, pathname, description = imp.find_module(plugin)
+            try:
+                pluginmodule = imp.load_module(plugin, fp, pathname, description)
+                add_plugin = True
+                if self.plugin_filter:
+                    class_name = getattr(pluginmodule, plugin)
+                    instance = class_name()
+                    add_plugin = self.plugin_filter.is_supported(instance)
+                if add_plugin:
+                    logging.info('Adding plugin %s to list', plugin)
+                    self.loaded_plugin[plugin] = pluginmodule
+                else:
+                    logging.info(
+                        'Skipping plugin %s as it does not match configured filter', plugin)
+            except Exception as exp:  # pylint: disable=broad-except
+                logging.error('Failed to load plugin %s, got exp %s', plugin, str(exp))
+                raise cmerror.CMError('Loading %s plugin failed' % plugin)
+            finally:
+                if fp:
+                    fp.close()
+
+    def build_filter_dict(self):
+        faulty_plugins = []
+        for plugin, objectname in self.loaded_plugin.iteritems():
+            logging.debug('Getting the subsription info from %s %s', plugin, objectname)
+            try:
+                class_name = getattr(objectname, plugin)
+                instance = class_name()
+                filtername = instance.get_subscription_info()
+                self.filterlist[plugin] = filtername
+            except Exception as exp:  # pylint: disable=broad-except
+                logging.error('Getting subscription failed for %s %s, got exp %s',
+                              plugin, objectname, str(exp))
+                faulty_plugins.append(plugin)
+
+        for plugin in faulty_plugins:
+            del self.loaded_plugin[plugin]
+
+    # pylint: disable=no-self-use
+    def validate_plugin(self):
+        pass
+
+    def load(self):
+        self.find_plugin()
+        self.sort_plugin()
+        self.load_plugin()
+        self.build_filter_dict()
+        return self.loaded_plugin, self.filterlist
+
+
+def main():
+    pl = CMPluginLoader("plug_in/tst")
+    a, b = pl.load()
+    print a
+    print b
+
+
+if __name__ == '__main__':
+    main()