--- /dev/null
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+#
+# 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.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+#
+# flake8: noqa
+
+import ops
+
+
+class BaseRelationClient(ops.framework.Object):
+
+ def __init__(
+ self,
+ charm: ops.charm.CharmBase,
+ relation_name: str,
+ mandatory_fields: list = [],
+ ):
+ super().__init__(charm, relation_name)
+ self.relation_name = relation_name
+ self.mandatory_fields = mandatory_fields
+ self._update_relation()
+
+ def get_data_from_unit(self, key: str):
+ if not self.relation:
+ # This update relation doesn't seem to be needed, but I added it because apparently
+ # the data is empty in the unit tests.
+ # In reality, the constructor is called in every hook.
+ # In the unit tests when doing an update_relation_data, apparently it is not called.
+ self._update_relation()
+ if self.relation:
+ for unit in self.relation.units:
+ data = self.relation.data[unit].get(key)
+ if data:
+ return data
+
+ def get_data_from_app(self, key: str):
+ if not self.relation or self.relation.app not in self.relation.data:
+ # This update relation doesn't seem to be needed, but I added it because apparently
+ # the data is empty in the unit tests.
+ # In reality, the constructor is called in every hook.
+ # In the unit tests when doing an update_relation_data, apparently it is not called.
+ self._update_relation()
+ if self.relation and self.relation.app in self.relation.data:
+ data = self.relation.data[self.relation.app].get(key)
+ if data:
+ return data
+
+ def is_missing_data_in_unit(self):
+ return not all([self.get_data_from_unit(field) for field in self.mandatory_fields])
+
+ def is_missing_data_in_app(self):
+ return not all([self.get_data_from_app(field) for field in self.mandatory_fields])
+
+ def _update_relation(self):
+ self.relation = self.framework.model.get_relation(self.relation_name)
+
+
+class MysqlClient(BaseRelationClient):
+ """Requires side of a Mysql Endpoint"""
+
+ mandatory_fields = ["host", "port", "user", "password", "root_password"]
+
+ def __init__(self, charm: ops.charm.CharmBase, relation_name: str):
+ super().__init__(charm, relation_name, self.mandatory_fields)
+
+ @property
+ def host(self):
+ return self.get_data_from_unit("host")
+
+ @property
+ def port(self):
+ return self.get_data_from_unit("port")
+
+ @property
+ def user(self):
+ return self.get_data_from_unit("user")
+
+ @property
+ def password(self):
+ return self.get_data_from_unit("password")
+
+ @property
+ def root_password(self):
+ return self.get_data_from_unit("root_password")
+
+ @property
+ def database(self):
+ return self.get_data_from_unit("database")
+
+ def get_root_uri(self, database: str):
+ """
+ Get the URI for the mysql connection with the root user credentials
+ :param: database: Database name
+ :return: A string with the following format:
+ mysql://root:<root_password>@<mysql_host>:<mysql_port>/<database>
+ """
+ return "mysql://root:{}@{}:{}/{}".format(
+ self.root_password, self.host, self.port, database
+ )
+
+ def get_uri(self):
+ """
+ Get the URI for the mysql connection with the standard user credentials
+ :param: database: Database name
+ :return: A string with the following format:
+ mysql://<user>:<password>@<mysql_host>:<mysql_port>/<database>
+ """
+ return "mysql://{}:{}@{}:{}/{}".format(
+ self.user, self.password, self.host, self.port, self.database
+ )