Merge ~ballot/cassandra-charm/+git/cassandra-charm:cRT#135443 into cassandra-charm:master

[Benjamin Allot]

Unmerged commits

82de0b6... by Benjamin Allot on 2022-04-09

Add missing LICENSE file

669f6ab... by Benjamin Allot on 2022-04-09

Add relation for cassandra metrics

This provides a cassandra-metrics relation, providing the listen address
and port used for cassandra.
To be used in relation with telegraf

83b618e... by Benjamin Allot on 2022-04-08

Allow charmcraft pack

Add the charmcraft.yaml file and ignore .charm files

06ad2e2... by William Grant on 2022-01-27

add external cluster options

diff --git a/LICENSE b/LICENSE
 new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/LICENSE
diff --git a/metadata.yaml b/metadata.yaml
index ca123a9..82f4709 100644
--- a/metadata.yaml
+++ b/metadata.yaml
@@ -34,6 +34,9 @@ provides:
     nrpe-external-master:
         interface: nrpe-external-master
         scope: container
+    cassandra-metrics:
+        interface: cassandra-metrics
+        scope: container
 peers:
     cluster:
         interface: cassandra-cluster
diff --git a/reactive/cassandra/metrics.py b/reactive/cassandra/metrics.py
 new file mode 100644
index 0000000..54bb4bf
--- /dev/null
+++ b/reactive/cassandra/metrics.py
@@ -0,0 +1,76 @@
+# Copyright 2015-2022 Canonical Ltd.
+#
+# This file is part of the Cassandra Charm for Juju.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3, as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranties of
+# MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+# PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import time
+
+from charmhelpers.core import (
+    hookenv,
+    host,
+)
+from charms import (
+    leadership,
+    reactive,
+)
+from charms.layer import cassandra
+from charms.reactive import (
+    when,
+    when_any,
+    when_not,
+)
+
+
+ENDPOINT = "cassandra-metrics"
+
+
+@when_any("config.changed",
+          "endpoint.cassandra-metrics.joined",
+          "endpoint.cassandra-metrics.departed",
+          "endpoint.cassandra-metrics.changed")
+def trigger_publish():
+    reactive.clear_flag("cassandra.metrics.published")
+
+
+@when_not("cassandra.metrics.published")
+@when(cassandra.metrics.available)
+def publish():
+    """Publish relation data needed for Cassandra metrics."""
+
+    relations = reactive.endpoint_from_name("cassandra-metrics")
+    if not relations:
+        return
+    hookenv.log("Relations: {}".format(relations), hookenv.DEBUG)
+    for rel in relations:
+        if rel.application_name is not None:
+            publish_listen_addr(rel)
+            publish_port(rel)
+
+    reactive.set_flag("cassandra.metrics.published")
+
+
+def publish_listen_addr(rel):
+    """Put the Cassandra unit address in the relation data."""
+
+    ip = hookenv.network_get(ENDPOINT)['bind-addresses'][0]['addresses'][0]['address']
+    hookenv.log("IP found for cassandra: {}".format(ip), hookenv.DEBUG)
+    rel.to_publish_raw["listen_address"] = ip
+
+
+def publish_port(rel):
+    """Put the Cassandra client port in the relation data."""
+
+    port = cassandra.read_cassandra_yaml()["native_transport_port"]
+    hookenv.log("Port found for cassandra: {}".format(port), hookenv.DEBUG)
+    rel.to_publish_raw["native_transport_port"] = port