--- /dev/null
+# 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.
+from charms.reactive import endpoint_from_flag
+from charms.layer.caas_base import pod_spec_set
+from charms.reactive import when, when_not, hook
+from charms.reactive.flags import set_flag, clear_flag
+from charmhelpers.core.hookenv import log, metadata, config
+from charms import layer
+
+
+@hook("upgrade-charm")
+@when("leadership.is_leader")
+def upgrade():
+ clear_flag("mon-k8s.configured")
+
+
+@when("config.changed")
+@when("leadership.is_leader")
+def restart():
+ clear_flag("mon-k8s.configured")
+
+
+@when_not("kafka.ready")
+@when_not("mon-k8s.configured")
+def waiting_for_kafka():
+ layer.status.waiting("Waiting for kafka to be ready")
+
+
+@when_not("mongo.ready")
+@when_not("mon-k8s.configured")
+def waiting_for_mongo():
+ layer.status.waiting("Waiting for mongo to be ready")
+
+
+@when_not("endpoint.prometheus.available")
+@when_not("mon-k8s.configured")
+def waiting_for_prometheus():
+ layer.status.waiting("Waiting for prometheus to be ready")
+
+
+@when("kafka.ready", "mongo.ready", "endpoint.prometheus.available")
+@when_not("mon-k8s.configured")
+@when("leadership.is_leader")
+def configure():
+ layer.status.maintenance("Configuring mon container")
+ try:
+ kafka = endpoint_from_flag("kafka.ready")
+ mongo = endpoint_from_flag("mongo.ready")
+ prometheus = endpoint_from_flag("endpoint.prometheus.available")
+
+ if kafka and mongo and prometheus:
+ kafka_units = kafka.kafkas()
+ kafka_unit = kafka_units[0]
+
+ mongo_uri = mongo.connection_string()
+ log("Mongo URI: {}".format(mongo_uri))
+
+ prometheus_url = prometheus.targets()[0]["targets"][0]
+
+ if mongo_uri and kafka_unit["host"]:
+
+ spec = make_pod_spec(
+ kafka_unit["host"], kafka_unit["port"], mongo_uri, prometheus_url
+ )
+
+ log("set pod spec:\n{}".format(spec))
+ pod_spec_set(spec)
+ set_flag("mon-k8s.configured")
+ except Exception as e:
+ layer.status.blocked("k8s spec failed to deploy: {}".format(e))
+
+
+@when("mon-k8s.configured")
+def set_mon_active():
+ layer.status.active("ready")
+
+
+def make_pod_spec(kafka_host, kafka_port, mongo_uri, prometheus_url):
+ """Make pod specification for Kubernetes
+
+ Args:
+ kafka_host (str): Kafka hostname or IP
+ kafka_port (int): Kafka port
+ mongo_uri (str): Mongo URI
+ Returns:
+ pod_spec: Pod specification for Kubernetes
+ """
+
+ with open("reactive/spec_template.yaml") as spec_file:
+ pod_spec_template = spec_file.read()
+
+ md = metadata()
+ cfg = config()
+
+ data = {
+ "name": md.get("name"),
+ "docker_image": cfg.get("image"),
+ "kafka_host": kafka_host,
+ "kafka_port": kafka_port,
+ "mongo_uri": mongo_uri,
+ "prometheus_url": prometheus_url,
+ }
+ data.update(cfg)
+ return pod_spec_template % data