Adding Kafka charm

[osm/devops.git] / installers / charm / kafka-k8s / reactive / kafka.py

diff --git a/installers/charm/kafka-k8s/reactive/kafka.py b/installers/charm/kafka-k8s/reactive/kafka.py
new file mode 100644 (file)
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+++ b/installers/charm/kafka-k8s/reactive/kafka.py
@@ -0,0 +1,139 @@
+# Copyright 2021 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
+##
+
+from charms.layer.caas_base import pod_spec_set
+from charms.reactive import when, when_not, hook
+from charms.reactive import endpoint_from_flag
+from charms.reactive.flags import set_flag, clear_flag
+from charmhelpers.core.hookenv import log, metadata, config
+from charms import layer
+from charms.osm.k8s import get_service_ip
+
+
+@hook("upgrade-charm")
+@when("leadership.is_leader")
+def upgrade():
+    clear_flag("kafka-k8s.configured")
+
+
+@when("config.changed")
+@when("leadership.is_leader")
+def restart():
+    clear_flag("kafka-k8s.configured")
+
+
+@when_not("zookeeper.ready")
+@when("leadership.is_leader")
+def waiting_for_zookeeper():
+    layer.status.waiting("Waiting for Zookeeper to be ready")
+
+
+@when("zookeeper.ready")
+@when_not("kafka-k8s.configured")
+@when("leadership.is_leader")
+def configure():
+    layer.status.maintenance("Configuring kafka container")
+    try:
+        zookeeper = endpoint_from_flag("zookeeper.ready")
+        zk_units = zookeeper.zookeepers()
+        zk_unit = zk_units[0]
+        if zk_unit["port"]:
+            cfg = config()
+            zookeeper_uri = ""
+            zk_pod_base_name = "zookeeper-k8s"
+            zk_service_name = cfg.get("zookeeper-service-name")
+            zk_num = cfg.get("zookeeper-units")
+            if zk_num == 1:
+                zookeeper_uri = "{}:{}".format(zk_unit["host"], zk_unit["port"])
+            else:
+                for i in range(0, zk_num):
+                    if i:
+                        zookeeper_uri += ","
+                    zookeeper_uri += "{}-{}.{}:{}".format(
+                        zk_pod_base_name, i, zk_service_name, zk_unit["port"]
+                    )
+            spec = make_pod_spec(zookeeper_uri)
+            log("set pod spec:\n{}".format(spec))
+            pod_spec_set(spec)
+            set_flag("kafka-k8s.configured")
+    except Exception as e:
+        layer.status.blocked("k8s spec failed to deploy: {}".format(e))
+
+
+@when("kafka-k8s.configured")
+def set_kafka_active():
+    layer.status.active("ready")
+
+
+@when("zookeeper.ready")
+@when_not("leadership.is_leader")
+def non_leaders_active():
+    layer.status.active("ready")
+
+
+@when("kafka-k8s.configured")
+@when("kafka.joined", "zookeeper.ready")
+def serve_client():
+    layer.status.maintenance("Sending kafka configuration")
+    try:
+        kafka = endpoint_from_flag("kafka.joined")
+        zookeeper = endpoint_from_flag("zookeeper.ready")
+        if zookeeper and kafka:
+            service_ip = get_service_ip("kafka")
+            if service_ip:
+                kafka.send_connection(
+                    get_kafka_port(), service_ip,
+                )
+                kafka.send_zookeepers(zookeeper.zookeepers())
+                clear_flag("kafka.joined")
+    except Exception as e:
+        log("Fail sending kafka configuration: {}".format(e))
+
+
+def make_pod_spec(zookeeper_uri):
+    """Make pod specification for Kubernetes
+
+    Args:
+        zookeeper_uri (str): Zookeeper hosts appended by comma.
+    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"),
+        "port": get_kafka_port(),
+        "zookeeper_uri": zookeeper_uri,
+    }
+    data.update(cfg)
+    return pod_spec_template % data
+
+
+def get_kafka_port():
+    """Returns Kafka port"""
+    cfg = config()
+    return cfg.get("advertised-port")