Merge v8.0 Into Master

[osm/devops.git] / installers / charm / pla / src / charm.py

diff --git a/installers/charm/pla/src/charm.py b/installers/charm/pla/src/charm.py
new file mode 100755 (executable)
index 0000000..1fc6386
--- /dev/null
+++ b/installers/charm/pla/src/charm.py
@@ -0,0 +1,147 @@
+#!/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.
+
+import sys
+import logging
+
+sys.path.append("lib")
+
+from ops.charm import CharmBase
+from ops.framework import StoredState, Object
+from ops.main import main
+from ops.model import (
+    ActiveStatus,
+    MaintenanceStatus,
+    WaitingStatus,
+)
+
+from glob import glob
+from pathlib import Path
+from string import Template
+
+logger = logging.getLogger(__name__)
+
+
+class PLACharm(CharmBase):
+    state = StoredState()
+
+    def __init__(self, framework, key):
+        super().__init__(framework, key)
+        self.state.set_default(spec=None)
+        self.state.set_default(kafka_host=None)
+        self.state.set_default(kafka_port=None)
+        self.state.set_default(mongodb_uri=None)
+
+        # Observe Charm related events
+        self.framework.observe(self.on.config_changed, self.on_config_changed)
+        self.framework.observe(self.on.start, self.on_start)
+        self.framework.observe(self.on.upgrade_charm, self.on_upgrade_charm)
+
+        # Relations
+        self.framework.observe(
+            self.on.kafka_relation_changed, self.on_kafka_relation_changed
+        )
+        self.framework.observe(
+            self.on.mongo_relation_changed, self.on_mongo_relation_changed
+        )
+
+    def _apply_spec(self):
+        # Only apply the spec if this unit is a leader.
+        unit = self.model.unit
+        if not unit.is_leader():
+            unit.status = ActiveStatus("ready")
+            return
+        if not self.state.kafka_host or not self.state.kafka_port:
+            unit.status = WaitingStatus("Waiting for Kafka")
+            return
+        if not self.state.mongodb_uri:
+            unit.status = WaitingStatus("Waiting for MongoDB")
+            return
+
+        unit.status = MaintenanceStatus("Applying new pod spec")
+
+        new_spec = self.make_pod_spec()
+        if new_spec == self.state.spec:
+            unit.status = ActiveStatus("ready")
+            return
+        self.framework.model.pod.set_spec(new_spec)
+        self.state.spec = new_spec
+        unit.status = ActiveStatus("ready")
+
+    def make_pod_spec(self):
+        config = self.framework.model.config
+
+        ports = [
+            {"name": "port", "containerPort": config["port"], "protocol": "TCP", },
+        ]
+
+        config_spec = {
+            "OSMPLA_MESSAGE_DRIVER": "kafka",
+            "OSMPLA_MESSAGE_HOST": self.state.kafka_host,
+            "OSMPLA_MESSAGE_PORT": self.state.kafka_port,
+            "OSMPLA_DATABASE_DRIVER": "mongo",
+            "OSMPLA_DATABASE_URI": self.state.mongodb_uri,
+            "OSMPLA_GLOBAL_LOG_LEVEL": config["log_level"],
+            "OSMPLA_DATABASE_COMMONKEY": config["database_common_key"],
+        }
+
+        spec = {
+            "version": 2,
+            "containers": [
+                {
+                    "name": self.framework.model.app.name,
+                    "image": config["image"],
+                    "ports": ports,
+                    "config": config_spec,
+                }
+            ],
+        }
+
+        return spec
+
+    def on_config_changed(self, event):
+        """Handle changes in configuration"""
+        self._apply_spec()
+
+    def on_start(self, event):
+        """Called when the charm is being installed"""
+        self._apply_spec()
+
+    def on_upgrade_charm(self, event):
+        """Upgrade the charm."""
+        unit = self.model.unit
+        unit.status = MaintenanceStatus("Upgrading charm")
+        self.on_start(event)
+
+    def on_kafka_relation_changed(self, event):
+        unit = self.model.unit
+        if not unit.is_leader():
+            return
+        self.state.kafka_host = event.relation.data[event.unit].get("host")
+        self.state.kafka_port = event.relation.data[event.unit].get("port")
+        self._apply_spec()
+
+    def on_mongo_relation_changed(self, event):
+        unit = self.model.unit
+        if not unit.is_leader():
+            return
+        self.state.mongodb_uri = event.relation.data[event.unit].get(
+            "connection_string"
+        )
+        self._apply_spec()
+
+
+if __name__ == "__main__":
+    main(PLACharm)