2 # Copyright 2020 Canonical Ltd.
4 # Licensed under the Apache License, Version 2.0 (the "License"); you may
5 # not use this file except in compliance with the License. You may obtain
6 # a copy of the License at
8 # http://www.apache.org/licenses/LICENSE-2.0
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 # License for the specific language governing permissions and limitations
16 # For those usages not covered by the Apache License, Version 2.0 please
17 # contact: legal@canonical.com
19 # To get in touch with the maintainers, please contact:
20 # osm-charmers@lists.launchpad.net
24 from typing
import Any
, Dict
, NoReturn
26 from ops
.charm
import CharmBase
, CharmEvents
27 from ops
.framework
import EventBase
, EventSource
, StoredState
28 from ops
.main
import main
29 from ops
.model
import ActiveStatus
, BlockedStatus
, MaintenanceStatus
30 from oci_image
import OCIImageResource
, OCIImageResourceError
32 from pod_spec
import make_pod_spec
34 logger
= logging
.getLogger(__name__
)
39 class ConfigurePodEvent(EventBase
):
40 """Configure Pod event"""
45 class LcmEvents(CharmEvents
):
48 configure_pod
= EventSource(ConfigurePodEvent
)
51 class LcmCharm(CharmBase
):
57 def __init__(self
, *args
) -> NoReturn
:
58 """LCM Charm constructor."""
59 super().__init
__(*args
)
61 # Internal state initialization
62 self
.state
.set_default(pod_spec
=None)
64 # Message bus data initialization
65 self
.state
.set_default(message_host
=None)
66 self
.state
.set_default(message_port
=None)
68 # Database data initialization
69 self
.state
.set_default(database_uri
=None)
71 # RO data initialization
72 self
.state
.set_default(ro_host
=None)
73 self
.state
.set_default(ro_port
=None)
76 self
.image
= OCIImageResource(self
, "image")
78 # Registering regular events
79 self
.framework
.observe(self
.on
.start
, self
.configure_pod
)
80 self
.framework
.observe(self
.on
.config_changed
, self
.configure_pod
)
81 self
.framework
.observe(self
.on
.upgrade_charm
, self
.configure_pod
)
83 # Registering custom internal events
84 self
.framework
.observe(self
.on
.configure_pod
, self
.configure_pod
)
86 # Registering required relation events
87 self
.framework
.observe(
88 self
.on
.kafka_relation_changed
, self
._on
_kafka
_relation
_changed
90 self
.framework
.observe(
91 self
.on
.mongodb_relation_changed
, self
._on
_mongodb
_relation
_changed
93 self
.framework
.observe(
94 self
.on
.ro_relation_changed
, self
._on
_ro
_relation
_changed
97 # Registering required relation departed events
98 self
.framework
.observe(
99 self
.on
.kafka_relation_departed
, self
._on
_kafka
_relation
_departed
101 self
.framework
.observe(
102 self
.on
.mongodb_relation_departed
, self
._on
_mongodb
_relation
_departed
104 self
.framework
.observe(
105 self
.on
.ro_relation_departed
, self
._on
_ro
_relation
_departed
108 def _on_kafka_relation_changed(self
, event
: EventBase
) -> NoReturn
:
109 """Reads information about the kafka relation.
112 event (EventBase): Kafka relation event.
114 message_host
= event
.relation
.data
[event
.unit
].get("host")
115 message_port
= event
.relation
.data
[event
.unit
].get("port")
121 self
.state
.message_host
!= message_host
122 or self
.state
.message_port
!= message_port
125 self
.state
.message_host
= message_host
126 self
.state
.message_port
= message_port
127 self
.on
.configure_pod
.emit()
129 def _on_kafka_relation_departed(self
, event
: EventBase
) -> NoReturn
:
130 """Clears data from kafka relation.
133 event (EventBase): Kafka relation event.
135 self
.state
.message_host
= None
136 self
.state
.message_port
= None
137 self
.on
.configure_pod
.emit()
139 def _on_mongodb_relation_changed(self
, event
: EventBase
) -> NoReturn
:
140 """Reads information about the DB relation.
143 event (EventBase): DB relation event.
145 database_uri
= event
.relation
.data
[event
.unit
].get("connection_string")
147 if database_uri
and self
.state
.database_uri
!= database_uri
:
148 self
.state
.database_uri
= database_uri
149 self
.on
.configure_pod
.emit()
151 def _on_mongodb_relation_departed(self
, event
: EventBase
) -> NoReturn
:
152 """Clears data from mongodb relation.
155 event (EventBase): DB relation event.
157 self
.state
.database_uri
= None
158 self
.on
.configure_pod
.emit()
160 def _on_ro_relation_changed(self
, event
: EventBase
) -> NoReturn
:
161 """Reads information about the RO relation.
164 event (EventBase): Keystone relation event.
166 ro_host
= event
.relation
.data
[event
.unit
].get("host")
167 ro_port
= event
.relation
.data
[event
.unit
].get("port")
172 and (self
.state
.ro_host
!= ro_host
or self
.state
.ro_port
!= ro_port
)
174 self
.state
.ro_host
= ro_host
175 self
.state
.ro_port
= ro_port
176 self
.on
.configure_pod
.emit()
178 def _on_ro_relation_departed(self
, event
: EventBase
) -> NoReturn
:
179 """Clears data from ro relation.
182 event (EventBase): Keystone relation event.
184 self
.state
.ro_host
= None
185 self
.state
.ro_port
= None
186 self
.on
.configure_pod
.emit()
188 def _missing_relations(self
) -> str:
189 """Checks if there missing relations.
192 str: string with missing relations
195 "kafka": self
.state
.message_host
,
196 "mongodb": self
.state
.database_uri
,
197 "ro": self
.state
.ro_host
,
200 missing_relations
= [k
for k
, v
in data_status
.items() if not v
]
202 return ", ".join(missing_relations
)
205 def relation_state(self
) -> Dict
[str, Any
]:
206 """Collects relation state configuration for pod spec assembly.
209 Dict[str, Any]: relation state information.
212 "message_host": self
.state
.message_host
,
213 "message_port": self
.state
.message_port
,
214 "database_uri": self
.state
.database_uri
,
215 "ro_host": self
.state
.ro_host
,
216 "ro_port": self
.state
.ro_port
,
219 return relation_state
221 def configure_pod(self
, event
: EventBase
) -> NoReturn
:
222 """Assemble the pod spec and apply it, if possible.
225 event (EventBase): Hook or Relation event that started the
228 if missing
:= self
._missing
_relations
():
229 self
.unit
.status
= BlockedStatus(
230 "Waiting for {0} relation{1}".format(
231 missing
, "s" if "," in missing
else ""
236 if not self
.unit
.is_leader():
237 self
.unit
.status
= ActiveStatus("ready")
240 self
.unit
.status
= MaintenanceStatus("Assembling pod spec")
242 # Fetch image information
244 self
.unit
.status
= MaintenanceStatus("Fetching image information")
245 image_info
= self
.image
.fetch()
246 except OCIImageResourceError
:
247 self
.unit
.status
= BlockedStatus("Error fetching image information")
251 pod_spec
= make_pod_spec(
258 except ValueError as exc
:
259 logger
.exception("Config/Relation data validation error")
260 self
.unit
.status
= BlockedStatus(str(exc
))
263 if self
.state
.pod_spec
!= pod_spec
:
264 self
.model
.pod
.set_spec(pod_spec
)
265 self
.state
.pod_spec
= pod_spec
267 self
.unit
.status
= ActiveStatus("ready")
270 if __name__
== "__main__":