installers/charm/prometheus-k8s/reactive/prometheus.py

   1 # Copyright 2021 Canonical Ltd.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   4 # not use this file except in compliance with the License. You may obtain
   5 # 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, WITHOUT
  11 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  12 # License for the specific language governing permissions and limitations
  13 # under the License.
  14 #
  15 # For those usages not covered by the Apache License, Version 2.0 please
  16 # contact: legal@canonical.com
  17 #
  18 # To get in touch with the maintainers, please contact:
  19 # osm-charmers@lists.launchpad.net
  20 ##
  21
  22 from charms.reactive import when, when_not, hook
  23 from charms.reactive.flags import set_flag, clear_flag
  24 from charmhelpers.core.hookenv import (
  25     log,
  26     metadata,
  27     config,
  28     network_get,
  29     relation_id,
  30 )
  31 from charms import layer
  32 from charmhelpers.core import hookenv
  33 import traceback
  34
  35
  36 @hook("upgrade-charm")
  37 @when("leadership.is_leader")
  38 def upgrade():
  39     clear_flag("prometheus-k8s.configured")
  40
  41
  42 @when("config.changed")
  43 @when("leadership.is_leader")
  44 def restart():
  45     clear_flag("prometheus-k8s.configured")
  46
  47
  48 @when_not("prometheus-k8s.configured")
  49 @when("leadership.is_leader")
  50 def configure():
  51     layer.status.maintenance("Configuring prometheus container")
  52     try:
  53         spec = make_pod_spec()
  54         log("set pod spec:\n{}".format(spec))
  55         layer.caas_base.pod_spec_set(spec)
  56         set_flag("prometheus-k8s.configured")
  57         layer.status.active("ready")
  58
  59     except Exception as e:
  60         layer.status.blocked("k8s spec failed to deploy: {}".format(e))
  61         log(traceback.format_exc(), level=hookenv.ERROR)
  62
  63
  64 @when("prometheus-k8s.configured")
  65 def set_prometheus_active():
  66     layer.status.active("ready")
  67
  68
  69 @when_not("leadership.is_leader")
  70 def non_leaders_active():
  71     layer.status.active("ready")
  72
  73
  74 @when("prometheus-k8s.configured", "endpoint.prometheus.available")
  75 def send_config(prometheus):
  76     layer.status.maintenance("Sending prometheus configuration")
  77     cfg = config()
  78     try:
  79         info = network_get("prometheus", relation_id())
  80         log("network info {0}".format(info))
  81         host = info.get("ingress-addresses", [""])[0]
  82
  83         prometheus.configure(hostname=host, port=cfg.get("advertised-port"))
  84         clear_flag("endpoint.prometheus.available")
  85     except Exception as e:
  86         log("Exception sending config: {}".format(e))
  87
  88
  89 def make_pod_spec():
  90     """Make pod specification for Kubernetes
  91
  92     Returns:
  93         pod_spec: Pod specification for Kubernetes
  94     """
  95     with open("reactive/spec_template.yaml") as spec_file:
  96         pod_spec_template = spec_file.read()
  97
  98     md = metadata()
  99     cfg = config()
 100
 101     data = {
 102         "name": md.get("name"),
 103         "docker_image": cfg.get("prometheus-image"),
 104         "a_docker_image": cfg.get("alpine-image"),
 105     }
 106     data.update(cfg)
 107     return pod_spec_template % data