Refactoring NBI Charm to use Operator Framework
This refactoring work includes tests.
Note 1: old charm is in nbi-k8s folder.
Note 2: relation-departed is currently not tested because there is
no function to remove a relation in the Testing Harness.
There is currently one issue open and the Charmcraft team
should provide feedback soon.
Change-Id: I25b94d205d2a004946189a231b5309da1deaa8ed
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/installers/charm/nbi/src/charm.py b/installers/charm/nbi/src/charm.py
new file mode 100755
index 0000000..f0347e2
--- /dev/null
+++ b/installers/charm/nbi/src/charm.py
@@ -0,0 +1,381 @@
+#!/usr/bin/env python3
+# Copyright 2020 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
+##
+
+import logging
+from typing import Any, Dict, NoReturn
+from pydantic import ValidationError
+
+from ops.charm import CharmBase, CharmEvents
+from ops.framework import EventBase, EventSource, StoredState
+from ops.main import main
+from ops.model import ActiveStatus, BlockedStatus, MaintenanceStatus
+from oci_image import OCIImageResource, OCIImageResourceError
+
+from pod_spec import make_pod_spec
+
+LOGGER = logging.getLogger(__name__)
+
+NBI_PORT = 9999
+
+
+class ConfigurePodEvent(EventBase):
+ """Configure Pod event"""
+
+ pass
+
+
+class NbiEvents(CharmEvents):
+ """NBI Events"""
+
+ configure_pod = EventSource(ConfigurePodEvent)
+
+
+class NbiCharm(CharmBase):
+ """NBI Charm."""
+
+ state = StoredState()
+ on = NbiEvents()
+
+ def __init__(self, *args) -> NoReturn:
+ """NBI Charm constructor."""
+ super().__init__(*args)
+
+ # Internal state initialization
+ self.state.set_default(pod_spec=None)
+
+ # Message bus data initialization
+ self.state.set_default(message_host=None)
+ self.state.set_default(message_port=None)
+
+ # Database data initialization
+ self.state.set_default(database_uri=None)
+
+ # Prometheus data initialization
+ self.state.set_default(prometheus_host=None)
+ self.state.set_default(prometheus_port=None)
+
+ # Keystone data initialization
+ self.state.set_default(keystone_host=None)
+ self.state.set_default(keystone_port=None)
+ self.state.set_default(keystone_user_domain_name=None)
+ self.state.set_default(keystone_project_domain_name=None)
+ self.state.set_default(keystone_username=None)
+ self.state.set_default(keystone_password=None)
+ self.state.set_default(keystone_service=None)
+
+ self.port = NBI_PORT
+ self.image = OCIImageResource(self, "image")
+
+ # Registering regular events
+ self.framework.observe(self.on.start, self.configure_pod)
+ self.framework.observe(self.on.config_changed, self.configure_pod)
+ self.framework.observe(self.on.upgrade_charm, self.configure_pod)
+
+ # Registering custom internal events
+ self.framework.observe(self.on.configure_pod, self.configure_pod)
+
+ # Registering required relation changed events
+ self.framework.observe(
+ self.on.kafka_relation_changed, self._on_kafka_relation_changed
+ )
+ self.framework.observe(
+ self.on.mongodb_relation_changed, self._on_mongodb_relation_changed
+ )
+ self.framework.observe(
+ self.on.keystone_relation_changed, self._on_keystone_relation_changed
+ )
+ self.framework.observe(
+ self.on.prometheus_relation_changed, self._on_prometheus_relation_changed
+ )
+
+ # Registering required relation departed events
+ self.framework.observe(
+ self.on.kafka_relation_departed, self._on_kafka_relation_departed
+ )
+ self.framework.observe(
+ self.on.mongodb_relation_departed, self._on_mongodb_relation_departed
+ )
+ self.framework.observe(
+ self.on.keystone_relation_departed, self._on_keystone_relation_departed
+ )
+ self.framework.observe(
+ self.on.prometheus_relation_departed, self._on_prometheus_relation_departed
+ )
+
+ # Registering provided relation events
+ self.framework.observe(self.on.nbi_relation_joined, self._publish_nbi_info)
+
+ def _on_kafka_relation_changed(self, event: EventBase) -> NoReturn:
+ """Reads information about the kafka relation.
+
+ Args:
+ event (EventBase): Kafka relation event.
+ """
+ message_host = event.relation.data[event.unit].get("host")
+ message_port = event.relation.data[event.unit].get("port")
+
+ if (
+ message_host
+ and message_port
+ and (
+ self.state.message_host != message_host
+ or self.state.message_port != message_port
+ )
+ ):
+ self.state.message_host = message_host
+ self.state.message_port = message_port
+ self.on.configure_pod.emit()
+
+ def _on_kafka_relation_departed(self, event: EventBase) -> NoReturn:
+ """Clears data from kafka relation.
+
+ Args:
+ event (EventBase): Kafka relation event.
+ """
+ self.state.message_host = None
+ self.state.message_port = None
+ self.on.configure_pod.emit()
+
+ def _on_mongodb_relation_changed(self, event: EventBase) -> NoReturn:
+ """Reads information about the DB relation.
+
+ Args:
+ event (EventBase): DB relation event.
+ """
+ database_uri = event.relation.data[event.unit].get("connection_string")
+
+ if database_uri and self.state.database_uri != database_uri:
+ self.state.database_uri = database_uri
+ self.on.configure_pod.emit()
+
+ def _on_mongodb_relation_departed(self, event: EventBase) -> NoReturn:
+ """Clears data from mongodb relation.
+
+ Args:
+ event (EventBase): DB relation event.
+ """
+ self.state.database_uri = None
+ self.on.configure_pod.emit()
+
+ def _on_keystone_relation_changed(self, event: EventBase) -> NoReturn:
+ """Reads information about the keystone relation.
+
+ Args:
+ event (EventBase): Keystone relation event.
+ """
+ keystone_host = event.relation.data[event.unit].get("host")
+ keystone_port = event.relation.data[event.unit].get("port")
+ keystone_user_domain_name = event.relation.data[event.unit].get(
+ "user_domain_name"
+ )
+ keystone_project_domain_name = event.relation.data[event.unit].get(
+ "project_domain_name"
+ )
+ keystone_username = event.relation.data[event.unit].get("username")
+ keystone_password = event.relation.data[event.unit].get("password")
+ keystone_service = event.relation.data[event.unit].get("service")
+
+ if (
+ keystone_host
+ and keystone_port
+ and keystone_user_domain_name
+ and keystone_project_domain_name
+ and keystone_username
+ and keystone_password
+ and keystone_service
+ and (
+ self.state.keystone_host != keystone_host
+ or self.state.keystone_port != keystone_port
+ or self.state.keystone_user_domain_name != keystone_user_domain_name
+ or self.state.keystone_project_domain_name
+ != keystone_project_domain_name
+ or self.state.keystone_username != keystone_username
+ or self.state.keystone_password != keystone_password
+ or self.state.keystone_service != keystone_service
+ )
+ ):
+ self.state.keystone_host = keystone_host
+ self.state.keystone_port = keystone_port
+ self.state.keystone_user_domain_name = keystone_user_domain_name
+ self.state.keystone_project_domain_name = keystone_project_domain_name
+ self.state.keystone_username = keystone_username
+ self.state.keystone_password = keystone_password
+ self.state.keystone_service = keystone_service
+ self.on.configure_pod.emit()
+
+ def _on_keystone_relation_departed(self, event: EventBase) -> NoReturn:
+ """Clears data from keystone relation.
+
+ Args:
+ event (EventBase): Keystone relation event.
+ """
+ self.state.keystone_host = None
+ self.state.keystone_port = None
+ self.state.keystone_user_domain_name = None
+ self.state.keystone_project_domain_name = None
+ self.state.keystone_username = None
+ self.state.keystone_password = None
+ self.state.keystone_service = None
+ self.on.configure_pod.emit()
+
+ def _on_prometheus_relation_changed(self, event: EventBase) -> NoReturn:
+ """Reads information about the prometheus relation.
+
+ Args:
+ event (EventBase): Prometheus relation event.
+ """
+ prometheus_host = event.relation.data[event.unit].get("hostname")
+ prometheus_port = event.relation.data[event.unit].get("port")
+
+ if (
+ prometheus_host
+ and prometheus_port
+ and (
+ self.state.prometheus_host != prometheus_host
+ or self.state.prometheus_port != prometheus_port
+ )
+ ):
+ self.state.prometheus_host = prometheus_host
+ self.state.prometheus_port = prometheus_port
+ self.on.configure_pod.emit()
+
+ def _on_prometheus_relation_departed(self, event: EventBase) -> NoReturn:
+ """Clears data from prometheus relation.
+
+ Args:
+ event (EventBase): Prometheus relation event.
+ """
+ self.state.prometheus_host = None
+ self.state.prometheus_port = None
+ self.on.configure_pod.emit()
+
+ def _publish_nbi_info(self, event: EventBase) -> NoReturn:
+ """Publishes NBI information.
+
+ Args:
+ event (EventBase): NBI relation event.
+ """
+ if self.unit.is_leader():
+ rel_data = {
+ "host": self.model.app.name,
+ "port": str(NBI_PORT),
+ }
+ for k, v in rel_data.items():
+ event.relation.data[self.model.app][k] = v
+
+ def _missing_relations(self) -> str:
+ """Checks if there missing relations.
+
+ Returns:
+ str: string with missing relations
+ """
+ data_status = {
+ "kafka": self.state.message_host,
+ "mongodb": self.state.database_uri,
+ "prometheus": self.state.prometheus_host,
+ }
+
+ if self.model.config["auth_backend"] == "keystone":
+ data_status["keystone"] = self.state.keystone_host
+
+ missing_relations = [k for k, v in data_status.items() if not v]
+
+ return ", ".join(missing_relations)
+
+ @property
+ def relation_state(self) -> Dict[str, Any]:
+ """Collects relation state configuration for pod spec assembly.
+
+ Returns:
+ Dict[str, Any]: relation state information.
+ """
+ relation_state = {
+ "message_host": self.state.message_host,
+ "message_port": self.state.message_port,
+ "database_uri": self.state.database_uri,
+ "prometheus_host": self.state.prometheus_host,
+ "prometheus_port": self.state.prometheus_port,
+ }
+
+ if self.model.config["auth_backend"] == "keystone":
+ relation_state.update(
+ {
+ "keystone_host": self.state.keystone_host,
+ "keystone_port": self.state.keystone_port,
+ "keystone_user_domain_name": self.state.keystone_user_domain_name,
+ "keystone_project_domain_name": self.state.keystone_project_domain_name,
+ "keystone_username": self.state.keystone_username,
+ "keystone_password": self.state.keystone_password,
+ "keystone_service": self.state.keystone_service,
+ }
+ )
+
+ return relation_state
+
+ def configure_pod(self, event: EventBase) -> NoReturn:
+ """Assemble the pod spec and apply it, if possible.
+
+ Args:
+ event (EventBase): Hook or Relation event that started the
+ function.
+ """
+ if missing := self._missing_relations():
+ self.unit.status = BlockedStatus(
+ f"Waiting for {missing} relation{'s' if ',' in missing else ''}"
+ )
+ return
+
+ if not self.unit.is_leader():
+ self.unit.status = ActiveStatus("ready")
+ return
+
+ self.unit.status = MaintenanceStatus("Assembling pod spec")
+
+ # Fetch image information
+ try:
+ self.unit.status = MaintenanceStatus("Fetching image information")
+ image_info = self.image.fetch()
+ except OCIImageResourceError:
+ self.unit.status = BlockedStatus("Error fetching image information")
+ return
+
+ try:
+ pod_spec = make_pod_spec(
+ image_info,
+ self.model.config,
+ self.relation_state,
+ self.model.app.name,
+ self.port,
+ )
+ except ValidationError as exc:
+ self.unit.status = BlockedStatus(str(exc))
+ return
+
+ if self.state.pod_spec != pod_spec:
+ self.model.pod.set_spec(pod_spec)
+ self.state.pod_spec = pod_spec
+
+ self.unit.status = ActiveStatus("ready")
+
+
+if __name__ == "__main__":
+ main(NbiCharm)