installers/charm/mon-k8s/reactive/mon_k8s.py

   1 # Copyright 2020 Canonical Ltd.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 #     Unless required by applicable law or agreed to in writing, software
  10 #     distributed under the License is distributed on an "AS IS" BASIS,
  11 #     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 #     See the License for the specific language governing permissions and
  13 #     limitations under the License.
  14 from charms.reactive import endpoint_from_flag
  15 from charms.layer.caas_base import pod_spec_set
  16 from charms.reactive import when, when_not, hook
  17 from charms.reactive.flags import set_flag, clear_flag
  18 from charmhelpers.core.hookenv import log, metadata, config
  19 from charms import layer
  20
  21
  22 @hook("upgrade-charm")
  23 @when("leadership.is_leader")
  24 def upgrade():
  25     clear_flag("mon-k8s.configured")
  26
  27
  28 @when("config.changed")
  29 @when("leadership.is_leader")
  30 def restart():
  31     clear_flag("mon-k8s.configured")
  32
  33
  34 @when_not("kafka.ready")
  35 @when_not("mon-k8s.configured")
  36 def waiting_for_kafka():
  37     layer.status.waiting("Waiting for kafka to be ready")
  38
  39
  40 @when_not("mongo.ready")
  41 @when_not("mon-k8s.configured")
  42 def waiting_for_mongo():
  43     layer.status.waiting("Waiting for mongo to be ready")
  44
  45
  46 @when_not("endpoint.prometheus.available")
  47 @when_not("mon-k8s.configured")
  48 def waiting_for_prometheus():
  49     layer.status.waiting("Waiting for prometheus to be ready")
  50
  51
  52 @when("kafka.ready", "mongo.ready", "endpoint.prometheus.available")
  53 @when_not("mon-k8s.configured")
  54 @when("leadership.is_leader")
  55 def configure():
  56     layer.status.maintenance("Configuring mon container")
  57     try:
  58         kafka = endpoint_from_flag("kafka.ready")
  59         mongo = endpoint_from_flag("mongo.ready")
  60         prometheus = endpoint_from_flag("endpoint.prometheus.available")
  61
  62         if kafka and mongo and prometheus:
  63             kafka_units = kafka.kafkas()
  64             kafka_unit = kafka_units[0]
  65
  66             mongo_uri = mongo.connection_string()
  67             log("Mongo URI: {}".format(mongo_uri))
  68
  69             prometheus_url = prometheus.targets()[0]["targets"][0]
  70
  71             if mongo_uri and kafka_unit["host"]:
  72
  73                 spec = make_pod_spec(
  74                     kafka_unit["host"], kafka_unit["port"], mongo_uri, prometheus_url
  75                 )
  76
  77                 log("set pod spec:\n{}".format(spec))
  78                 pod_spec_set(spec)
  79                 set_flag("mon-k8s.configured")
  80     except Exception as e:
  81         layer.status.blocked("k8s spec failed to deploy: {}".format(e))
  82
  83
  84 @when("mon-k8s.configured")
  85 def set_mon_active():
  86     layer.status.active("ready")
  87
  88
  89 def make_pod_spec(kafka_host, kafka_port, mongo_uri, prometheus_url):
  90     """Make pod specification for Kubernetes
  91
  92     Args:
  93         kafka_host (str): Kafka hostname or IP
  94         kafka_port (int): Kafka port
  95         mongo_uri (str): Mongo URI
  96     Returns:
  97         pod_spec: Pod specification for Kubernetes
  98     """
  99
 100     with open("reactive/spec_template.yaml") as spec_file:
 101         pod_spec_template = spec_file.read()
 102
 103     md = metadata()
 104     cfg = config()
 105
 106     data = {
 107         "name": md.get("name"),
 108         "docker_image": cfg.get("image"),
 109         "kafka_host": kafka_host,
 110         "kafka_port": kafka_port,
 111         "mongo_uri": mongo_uri,
 112         "prometheus_url": prometheus_url,
 113     }
 114     data.update(cfg)
 115     return pod_spec_template % data