installers/charm/pla/src/charm.py

   1 #!/usr/bin/env python3
   2 #   Copyright 2020 Canonical Ltd.
   3 #
   4 #   Licensed under the Apache License, Version 2.0 (the "License");
   5 #   you may not use this file except in compliance with the License.
   6 #   You may obtain a copy of the License at
   7 #
   8 #       http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 #   Unless required by applicable law or agreed to in writing, software
  11 #   distributed under the License is distributed on an "AS IS" BASIS,
  12 #   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 #   See the License for the specific language governing permissions and
  14 #   limitations under the License.
  15
  16 import sys
  17 import logging
  18
  19 sys.path.append("lib")
  20
  21 from ops.charm import CharmBase
  22 from ops.framework import StoredState, Object
  23 from ops.main import main
  24 from ops.model import (
  25     ActiveStatus,
  26     MaintenanceStatus,
  27 )
  28
  29 from glob import glob
  30 from pathlib import Path
  31 from string import Template
  32
  33 logger = logging.getLogger(__name__)
  34
  35
  36 class PLACharm(CharmBase):
  37     state = StoredState()
  38
  39     def __init__(self, framework, key):
  40         super().__init__(framework, key)
  41         self.state.set_default(spec=None)
  42
  43         # Observe Charm related events
  44         self.framework.observe(self.on.config_changed, self.on_config_changed)
  45         self.framework.observe(self.on.start, self.on_start)
  46         self.framework.observe(self.on.upgrade_charm, self.on_upgrade_charm)
  47
  48     def _apply_spec(self):
  49         # Only apply the spec if this unit is a leader.
  50         if not self.framework.model.unit.is_leader():
  51             return
  52         new_spec = self.make_pod_spec()
  53         if new_spec == self.state.spec:
  54             return
  55         self.framework.model.pod.set_spec(new_spec)
  56         self.state.spec = new_spec
  57
  58     def make_pod_spec(self):
  59         config = self.framework.model.config
  60
  61         ports = [
  62             {"name": "port", "containerPort": config["port"], "protocol": "TCP",},
  63         ]
  64
  65         kubernetes = {
  66             "readinessProbe": {
  67                 "tcpSocket": {"port": config["port"]},
  68                 "timeoutSeconds": 5,
  69                 "periodSeconds": 5,
  70                 "initialDelaySeconds": 10,
  71             },
  72             "livenessProbe": {
  73                 "tcpSocket": {"port": config["port"]},
  74                 "timeoutSeconds": 5,
  75                 "initialDelaySeconds": 45,
  76             },
  77         }
  78         config_spec = {
  79             "OSMPLA_MESSAGE_DRIVER": "kafka",
  80             "OSMPLA_MESSAGE_HOST": config["kafka_host"],
  81             "OSMPLA_MESSAGE_PORT": config["kafka_port"],
  82             "OSMPLA_DATABASE_DRIVER": "mongo",
  83             "OSMPLA_DATABASE_URI": config["mongo_uri"],
  84             "OSMPLA_GLOBAL_LOG_LEVEL": config["log_level"],
  85         }
  86
  87         spec = {
  88             "version": 2,
  89             "containers": [
  90                 {
  91                     "name": self.framework.model.app.name,
  92                     "image": "{}".format(config["image"]),
  93                     "ports": ports,
  94                     "kubernetes": kubernetes,
  95                     "config": config_spec,
  96                 }
  97             ],
  98         }
  99
 100         return spec
 101
 102     def on_config_changed(self, event):
 103         """Handle changes in configuration"""
 104         unit = self.model.unit
 105         unit.status = MaintenanceStatus("Applying new pod spec")
 106         self._apply_spec()
 107         unit.status = ActiveStatus("Ready")
 108
 109     def on_start(self, event):
 110         """Called when the charm is being installed"""
 111         unit = self.model.unit
 112         unit.status = MaintenanceStatus("Applying pod spec")
 113         self._apply_spec()
 114         unit.status = ActiveStatus("Ready")
 115
 116     def on_upgrade_charm(self, event):
 117         """Upgrade the charm."""
 118         unit = self.model.unit
 119         unit.status = MaintenanceStatus("Upgrading charm")
 120         self.on_start(event)
 121
 122
 123 if __name__ == "__main__":
 124     main(PLACharm)