installers/charm/grafana-k8s/reactive/grafana.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.layer.caas_base import pod_spec_set
  23 from charms.reactive import endpoint_from_flag
  24 from charms.reactive import when, when_not, hook
  25 from charms.reactive.flags import set_flag, clear_flag
  26 from charmhelpers.core.hookenv import (
  27     log,
  28     metadata,
  29     config,
  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("grafana-k8s.configured")
  40
  41
  42 @when("config.changed")
  43 @when("leadership.is_leader")
  44 def restart():
  45     clear_flag("grafana-k8s.configured")
  46
  47
  48 @when_not("endpoint.prometheus.available")
  49 @when("leadership.is_leader")
  50 def waiting_for_prometheus_interface():
  51     layer.status.waiting("Waiting for prometheus interface")
  52
  53
  54 @when("endpoint.prometheus.available")
  55 @when_not("grafana-k8s.configured")
  56 @when("leadership.is_leader")
  57 def configure():
  58     layer.status.maintenance("Configuring grafana container")
  59     try:
  60         prometheus = endpoint_from_flag("endpoint.prometheus.available")
  61         prometheus_url = prometheus.targets()[0]["targets"][0]
  62
  63         if prometheus_url:
  64             spec = make_pod_spec(prometheus_url)
  65             log("set pod spec:\n{}".format(spec))
  66             pod_spec_set(spec)
  67             set_flag("grafana-k8s.configured")
  68             layer.status.active("ready")
  69
  70     except Exception as e:
  71         layer.status.blocked("k8s spec failed to deploy: {}".format(e))
  72         log(traceback.format_exc(), level=hookenv.ERROR)
  73
  74
  75 @when("grafana-k8s.configured")
  76 def set_grafana_active():
  77     layer.status.active("ready")
  78
  79
  80 @when("endpoint.prometheus.available")
  81 @when_not("leadership.is_leader")
  82 def non_leaders_active():
  83     layer.status.active("ready")
  84
  85
  86 def make_pod_spec(prometheus_url):
  87     """Make pod specification for Kubernetes
  88
  89     Returns:
  90         pod_spec: Pod specification for Kubernetes
  91     """
  92     with open("reactive/spec_template.yaml") as spec_file:
  93         pod_spec_template = spec_file.read()
  94
  95     md = metadata()
  96     cfg = config()
  97
  98     data = {
  99         "name": md.get("name"),
 100         "docker_image": cfg.get("image"),
 101         "prometheus_url": prometheus_url,
 102     }
 103     data.update(cfg)
 104     return pod_spec_template % data