Merge pull request #42 from canonical/update-libs

[DPE-4757] Pre-cursor to supporting upgrades -  Update MongoDB libs

lib/charms/mongodb/v0/config_server_interface.py

@@ -42,7 +42,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 10
+LIBPATCH = 12
 
 
 class ClusterProvider(Object):
@@ -85,6 +85,13 @@ def pass_hook_checks(self, event: EventBase) -> bool:
         if not self.charm.unit.is_leader():
             return False
 
+        if self.charm.upgrade_in_progress:
+            logger.warning(
+                "Processing mongos applications is not supported during an upgrade. The charm may be in a broken, unrecoverable state."
+            )
+            event.defer()
+            return False
+
         return True
 
     def is_valid_mongos_integration(self) -> bool:
@@ -130,6 +137,11 @@ def _on_relation_changed(self, event) -> None:
         self.database_provides.update_relation_data(event.relation.id, relation_data)
 
     def _on_relation_broken(self, event) -> None:
+        if self.charm.upgrade_in_progress:
+            logger.warning(
+                "Removing integration to mongos is not supported during an upgrade. The charm may be in a broken, unrecoverable state."
+            )
+
         # Only relation_deparated events can check if scaling down
         departed_relation_id = event.relation.id
         if not self.charm.has_departed_run(departed_relation_id):
@@ -172,7 +184,7 @@ def generate_config_server_db(self) -> str:
         """Generates the config server database for mongos to connect to."""
         replica_set_name = self.charm.app.name
         hosts = []
-        for host in self.charm._unit_ips:
+        for host in self.charm.unit_ips:
             hosts.append(f"{host}:{Config.MONGODB_PORT}")
 
         hosts = ",".join(hosts)
@@ -378,7 +390,7 @@ def get_tls_statuses(self) -> Optional[StatusBase]:
             )
             return BlockedStatus("mongos CA and Config-Server CA don't match.")
 
-        return
+        return None
 
     def get_config_server_name(self) -> Optional[str]:
         """Returns the name of the Juju Application that mongos is using as a config server."""

lib/charms/mongodb/v0/mongodb.py

@@ -1,4 +1,5 @@
 """Code for interactions with MongoDB."""
+
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 
@@ -21,6 +22,8 @@
     wait_fixed,
 )
 
+from config import Config
+
 # The unique Charmhub library identifier, never change it
 LIBID = "49c69d9977574dd7942eb7b54f43355b"
 
@@ -29,12 +32,16 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 7
+LIBPATCH = 9
 
 # path to store mongodb ketFile
 logger = logging.getLogger(__name__)
 
 
+class FailedToMovePrimaryError(Exception):
+    """Raised when attempt to move a primary fails."""
+
+
 @dataclass
 class MongoDBConfiguration:
     """Class for MongoDB configuration.
@@ -56,6 +63,7 @@ class MongoDBConfiguration:
     roles: Set[str]
     tls_external: bool
     tls_internal: bool
+    standalone: bool = False
 
     @property
     def uri(self):
@@ -65,6 +73,14 @@ def uri(self):
         auth_source = ""
         if self.database != "admin":
             auth_source = "&authSource=admin"
+
+        if self.standalone:
+            return (
+                f"mongodb://{quote_plus(self.username)}:"
+                f"{quote_plus(self.password)}@"
+                f"localhost:{Config.MONGODB_PORT}/?authSource=admin"
+            )
+
         return (
             f"mongodb://{quote_plus(self.username)}:"
             f"{quote_plus(self.password)}@"
@@ -224,7 +240,7 @@ def add_replset_member(self, hostname: str) -> None:
         # Such operation reduce performance of the cluster. To avoid huge performance
         # degradation, before adding new members, it is needed to check that all other
         # members finished init sync.
-        if self._is_any_sync(rs_status):
+        if self.is_any_sync(rs_status):
             # it can take a while, we should defer
             raise NotReadyError
 
@@ -274,6 +290,64 @@ def remove_replset_member(self, hostname: str) -> None:
         logger.debug("rs_config: %r", dumps(rs_config["config"]))
         self.client.admin.command("replSetReconfig", rs_config["config"])
 
+    def step_down_primary(self) -> None:
+        """Steps down the current primary, forcing a re-election."""
+        self.client.admin.command("replSetStepDown", {"stepDownSecs": "60"})
+
+    def move_primary(self, new_primary_ip: str) -> None:
+        """Forcibly moves the primary to the new primary provided.
+
+        Args:
+            new_primary_ip: ip address of the unit chosen to be the new primary.
+        """
+        # Do not move a priary unless the cluster is in sync
+        rs_status = self.client.admin.command("replSetGetStatus")
+        if self.is_any_sync(rs_status):
+            # it can take a while, we should defer
+            raise NotReadyError
+
+        is_move_successful = True
+        self.set_replicaset_election_priority(priority=0.5, ignore_member=new_primary_ip)
+        try:
+            for attempt in Retrying(stop=stop_after_delay(180), wait=wait_fixed(3)):
+                with attempt:
+                    self.step_down_primary()
+                    if self.primary() != new_primary_ip:
+                        raise FailedToMovePrimaryError
+        except RetryError:
+            # catch all possible exceptions when failing to step down primary. We do this in order
+            # to ensure that we reset the replica set election priority.
+            is_move_successful = False
+
+        # reset all replicas to the same priority
+        self.set_replicaset_election_priority(priority=1)
+
+        if not is_move_successful:
+            raise FailedToMovePrimaryError
+
+    def set_replicaset_election_priority(self, priority: int, ignore_member: str = None) -> None:
+        """Set the election priority for the entire replica set."""
+        rs_config = self.client.admin.command("replSetGetConfig")
+        rs_config = rs_config["config"]
+        rs_config["version"] += 1
+
+        # keep track of the original configuration before setting the priority, reconfiguring the
+        # replica set can result in primary re-election, which would would like to avoid when
+        # possible.
+        original_rs_config = rs_config
+
+        for member in rs_config["members"]:
+            if member["host"] == ignore_member:
+                continue
+
+            member["priority"] = priority
+
+        if original_rs_config == rs_config:
+            return
+
+        logger.debug("rs_config: %r", rs_config)
+        self.client.admin.command("replSetReconfig", rs_config)
+
     def create_user(self, config: MongoDBConfiguration):
         """Create user.
 
@@ -402,7 +476,7 @@ def primary(self) -> str:
         return primary
 
     @staticmethod
-    def _is_any_sync(rs_status: Dict) -> bool:
+    def is_any_sync(rs_status: Dict) -> bool:
         """Returns true if any replica set members are syncing data.
 
         Checks if any members in replica set are syncing data. Note it is recommended to run only

lib/charms/mongodb/v0/mongodb_secrets.py

@@ -1,4 +1,5 @@
 """Secrets related helper classes/functions."""
+
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 

lib/charms/mongodb/v0/mongodb_tls.py

@@ -13,10 +13,10 @@
 import socket
 from typing import List, Optional, Tuple
 
-from charms.tls_certificates_interface.v1.tls_certificates import (
+from charms.tls_certificates_interface.v3.tls_certificates import (
     CertificateAvailableEvent,
     CertificateExpiringEvent,
-    TLSCertificatesRequiresV1,
+    TLSCertificatesRequiresV3,
     generate_csr,
     generate_private_key,
 )
@@ -38,7 +38,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 12
+LIBPATCH = 14
 
 logger = logging.getLogger(__name__)
 
@@ -52,7 +52,7 @@ def __init__(self, charm, peer_relation, substrate):
         self.charm = charm
         self.substrate = substrate
         self.peer_relation = peer_relation
-        self.certs = TLSCertificatesRequiresV1(self.charm, Config.TLS.TLS_PEER_RELATION)
+        self.certs = TLSCertificatesRequiresV3(self.charm, Config.TLS.TLS_PEER_RELATION)
         self.framework.observe(
             self.charm.on.set_tls_private_key_action, self._on_set_tls_private_key
         )
@@ -81,6 +81,11 @@ def _on_set_tls_private_key(self, event: ActionEvent) -> None:
             event.fail("Mongos cannot set TLS keys until integrated to config-server.")
             return
 
+        if self.charm.upgrade_in_progress:
+            logger.warning("Setting TLS key during an upgrade is not supported.")
+            event.fail("Setting TLS key during an upgrade is not supported.")
+            return
+
         try:
             self.request_certificate(event.params.get("external-key", None), internal=False)
             self.request_certificate(event.params.get("internal-key", None), internal=True)
@@ -141,12 +146,23 @@ def _on_tls_relation_joined(self, event: RelationJoinedEvent) -> None:
             event.defer()
             return
 
+        if self.charm.upgrade_in_progress:
+            logger.warning(
+                "Enabling TLS is not supported during an upgrade. The charm may be in a broken, unrecoverable state."
+            )
+            event.defer()
+            return
+
         self.request_certificate(None, internal=True)
         self.request_certificate(None, internal=False)
 
     def _on_tls_relation_broken(self, event: RelationBrokenEvent) -> None:
         """Disable TLS when TLS relation broken."""
         logger.debug("Disabling external and internal TLS for unit: %s", self.charm.unit.name)
+        if self.charm.upgrade_in_progress:
+            logger.warning(
+                "Disabling TLS is not supported during an upgrade. The charm may be in a broken, unrecoverable state."
+            )
 
         for internal in [True, False]:
             self.set_tls_secret(internal, Config.TLS.SECRET_CA_LABEL, None)
@@ -320,7 +336,7 @@ def get_tls_files(self, internal: bool) -> Tuple[Optional[str], Optional[str]]:
     def get_host(self, unit: Unit):
         """Retrieves the hostname of the unit based on the substrate."""
         if self.substrate == "vm":
-            return self.charm._unit_ip(unit)
+            return self.charm.unit_ip(unit)
         else:
             return self.charm.get_hostname_for_unit(unit)
 

lib/charms/mongodb/v1/users.py

@@ -1,4 +1,5 @@
 """Users configuration for MongoDB."""
+
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 from typing import Set

lib/charms/mongos/v0/mongos_client_interface.py

@@ -11,7 +11,6 @@
 from ops.charm import CharmBase
 from charms.data_platform_libs.v0.data_interfaces import (
     DatabaseProvides,
-    DatabaseRequestedEvent,
 )
 
 from charms.mongodb.v1.mongos import MongosConfiguration
@@ -75,11 +74,15 @@ def __init__(self, *args):
 class MongosProvider(Object):
     """Manage relations between the mongos router and the application on the mongos side."""
 
-    def __init__(self, charm: CharmBase, relation_name: str = MONGOS_RELATION_NAME) -> None:
+    def __init__(
+        self, charm: CharmBase, relation_name: str = MONGOS_RELATION_NAME
+    ) -> None:
         """Constructor for MongosProvider object."""
         self.relation_name = relation_name
         self.charm = charm
-        self.database_provides = DatabaseProvides(self.charm, relation_name=self.relation_name)
+        self.database_provides = DatabaseProvides(
+            self.charm, relation_name=self.relation_name
+        )
 
         super().__init__(charm, self.relation_name)
         self.framework.observe(
@@ -98,7 +101,9 @@ def _on_relation_changed(self, event) -> None:
             or self.charm.database
         )
         new_extra_user_roles = (
-            self.database_provides.fetch_relation_field(event.relation.id, USER_ROLES_KEY)
+            self.database_provides.fetch_relation_field(
+                event.relation.id, USER_ROLES_KEY
+            )
             or self.charm.extra_user_roles
         )
         external_connectivity = (
@@ -133,7 +138,9 @@ def update_connection_info(self, config: MongosConfiguration) -> None:
         """Sends the URI to the related parent application"""
         logger.info("Sharing connection information to host application.")
         for relation in self.model.relations[MONGOS_RELATION_NAME]:
-            self.database_provides.set_credentials(relation.id, config.username, config.password)
+            self.database_provides.set_credentials(
+                relation.id, config.username, config.password
+            )
             self.database_provides.set_database(relation.id, config.database)
             self.database_provides.set_uris(
                 relation.id,