From 19ec143509ad9358d7ac61847e09a2130ccb46f6 Mon Sep 17 00:00:00 2001
From: Liam Young <liam.young@canonical.com>
Date: Thu, 14 Oct 2021 12:17:54 +0100
Subject: [PATCH] Support requesting a db name

---
 .../advanced_sunbeam_openstack/charm.py       |  3 +-
 .../relation_handlers.py                      | 12 +++-
 ops-sunbeam/lib/charms/mysql/v1/mysql.py      | 63 +++++++++++++++++--
 ops-sunbeam/unit_tests/test_core.py           |  3 +-
 4 files changed, 73 insertions(+), 8 deletions(-)

diff --git a/ops-sunbeam/advanced_sunbeam_openstack/charm.py b/ops-sunbeam/advanced_sunbeam_openstack/charm.py
index 7e9b4afa..f9ee63d6 100644
--- a/ops-sunbeam/advanced_sunbeam_openstack/charm.py
+++ b/ops-sunbeam/advanced_sunbeam_openstack/charm.py
@@ -89,7 +89,8 @@ class OSBaseOperatorCharm(ops.charm.CharmBase):
             self.db = sunbeam_rhandlers.DBHandler(
                 self,
                 db_svc,
-                self.configure_charm)
+                self.configure_charm,
+                [self.service_name.replace('-', '_')])
             handlers.append(self.db)
         if self.can_add_handler('ingress', handlers):
             self.ingress = sunbeam_rhandlers.IngressHandler(
diff --git a/ops-sunbeam/advanced_sunbeam_openstack/relation_handlers.py b/ops-sunbeam/advanced_sunbeam_openstack/relation_handlers.py
index 81763530..d6c9b91d 100644
--- a/ops-sunbeam/advanced_sunbeam_openstack/relation_handlers.py
+++ b/ops-sunbeam/advanced_sunbeam_openstack/relation_handlers.py
@@ -137,13 +137,23 @@ class IngressHandler(RelationHandler):
 class DBHandler(RelationHandler):
     """Handler for DB relations"""
 
+    def __init__(
+        self,
+        charm: ops.charm.CharmBase,
+        relation_name: str,
+        callback_f,
+        databases=None
+    ):
+        self.databases = databases
+        super().__init__(charm, relation_name, callback_f)
+
     def setup_event_handler(self) -> ops.charm.Object:
         """Configure event handlers for a MySQL relation."""
         logger.debug('Setting up DB event handler')
         db = mysql.MySQLConsumer(
             self.charm,
             self.relation_name,
-            {"mysql": ">=8"})
+            databases=self.databases)
         _rname = self.relation_name.replace('-', '_')
         db_relation_event = getattr(
             self.charm.on,
diff --git a/ops-sunbeam/lib/charms/mysql/v1/mysql.py b/ops-sunbeam/lib/charms/mysql/v1/mysql.py
index 6502bd22..84e14095 100644
--- a/ops-sunbeam/lib/charms/mysql/v1/mysql.py
+++ b/ops-sunbeam/lib/charms/mysql/v1/mysql.py
@@ -35,24 +35,69 @@ to get the relevant information from the relation data.
 import json
 import uuid
 import logging
-
 from ops.relation import ConsumerBase
 
+from ops.framework import (
+    StoredState,
+    EventBase,
+    ObjectEvents,
+    EventSource,
+    Object,
+)
+
 LIBID = "abcdef1234"  # Will change when uploding the charm to charmhub
 LIBAPI = 1
 LIBPATCH = 0
 logger = logging.getLogger(__name__)
 
+class DatabaseConnectedEvent(EventBase):
+    """Database connected Event."""
 
-class MySQLConsumer(ConsumerBase):
+    pass
+
+
+class DatabaseReadyEvent(EventBase):
+    """Database ready for use Event."""
+
+    pass
+
+
+class DatabaseGoneAwayEvent(EventBase):
+    """Database relation has gone-away Event"""
+
+    pass
+
+
+class DatabaseServerEvents(ObjectEvents):
+    """Events class for `on`"""
+
+    connected = EventSource(DatabaseConnectedEvent)
+    ready = EventSource(DatabaseReadyEvent)
+    goneaway = EventSource(DatabaseGoneAwayEvent)
+
+
+class MySQLConsumer(Object):
     """
     MySQLConsumer lib class
     """
 
-    def __init__(self, charm, name, consumes, multi=False):
-        super().__init__(charm, name, consumes, multi)
+    on = DatabaseServerEvents()
+
+    def __init__(self, charm, relation_name: str, databases: list):
+        super().__init__(charm, relation_name)
         self.charm = charm
-        self.relation_name = name
+        self.relation_name = relation_name
+        self.request_databases = databases
+        self.framework.observe(
+            self.charm.on[relation_name].relation_joined,
+            self._on_database_relation_joined,
+        )
+
+    def _on_database_relation_joined(self, event):
+        """AMQP relation joined."""
+        logging.debug("DatabaseRequires on_joined")
+        self.on.connected.emit()
+        self.request_access(self.request_databases)
 
     def databases(self, rel_id=None) -> list:
         """
@@ -103,3 +148,11 @@ class MySQLConsumer(ConsumerBase):
         dbs = json.loads(dbs) if dbs else []
         dbs.append(db_name)
         rel.data[self.charm.app]["databases"] = json.dumps(dbs)
+
+    def request_access(self, databases: list) -> None:
+        """Request access to the AMQP server."""
+        if self.model.unit.is_leader():
+            logging.debug("Requesting AMQP user and vhost")
+            if databases:
+                rel = self.framework.model.get_relation(self.relation_name)
+                rel.data[self.charm.app]["databases"] = json.dumps(databases)
diff --git a/ops-sunbeam/unit_tests/test_core.py b/ops-sunbeam/unit_tests/test_core.py
index f45a6a3d..1a6fd317 100644
--- a/ops-sunbeam/unit_tests/test_core.py
+++ b/ops-sunbeam/unit_tests/test_core.py
@@ -145,7 +145,8 @@ class TestOSBaseOperatorAPICharm(test_utils.CharmTestCase):
             db_rel_id,
             'my-service')
         requested_db = json.loads(rel_data['databases'])[0]
-        self.assertRegex(requested_db, r'^db_.*my_service$')
+        # self.assertRegex(requested_db, r'^db_.*my_service$')
+        self.assertEqual(requested_db, 'my_service')
 
     def test_contexts(self):
         self.harness.set_leader()