Grafana: Provision data sources via dynamic template in values

This moves to define the datasources provisioned by grafana via
a template defined in the values.yaml. This allows us to define
multiple datasource types that can be mapped directly to the
corresponding entries in endpoints, which enables us to generate
the data source urls via endpoint lookups rather than hardcoding
this. This is the first step to support multiple data sources in
a singular grafana deployment

Change-Id: Iac7f4b1e07aaf83ae4d2a0c923cd06817f0d8c0d

grafana/templates/configmap-etc.yaml

@@ -35,7 +35,7 @@ metadata:
   name: grafana-etc
 data:
   datasources.yaml: |
-{{ toYaml .Values.conf.provisioning.datasources | indent 4 }}
+{{- include "grafana.utils.generate_datasources" (dict "envAll" $envAll "datasources" .Values.conf.provisioning.datasources) | indent 4 }}
   dashboards.yaml: |
 {{ toYaml .Values.conf.provisioning.dashboards | indent 4 }}
   grafana.ini: |

grafana/templates/utils/_generate_datasources.tpl

@@ -0,0 +1,35 @@
+{{/*
+Copyright 2017 The Openstack-Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/}}
+
+# This function generates the required datasource configuration for grafana.
+# This allows us to generate an arbitrary number of datasources for grafana
+
+{{- define "grafana.utils.generate_datasources" -}}
+{{- $envAll := index . "envAll" -}}
+{{- $datasources := index . "datasources" -}}
+{{- $_ := set $envAll.Values "__datasources" ( list ) }}
+{{- range $datasource, $config := $datasources -}}
+{{- if empty $config.url -}}
+{{- $datasource_url := tuple $datasource "internal" "api" $envAll | include "helm-toolkit.endpoints.keystone_endpoint_uri_lookup" }}
+{{- $_ := set $config "url" $datasource_url }}
+{{- end }}
+{{- $__datasources := append $envAll.Values.__datasources $config }}
+{{- $_ := set $envAll.Values "__datasources" $__datasources }}
+{{- end }}
+apiVersion: 1
+datasources:
+{{ toYaml $envAll.Values.__datasources }}
+{{- end -}}

grafana/values.yaml

@@ -344,14 +344,15 @@ conf:
         options:
           path: /var/lib/grafana/dashboards
     datasources:
-      apiVersion: 1
-      datasources:
-      - name: prometheus
+      #NOTE(srwilkers): The top key for each datasource (eg: monitoring) must
+      # map to the key name for the datasource's endpoint entry in the endpoints
+      # tree
+      monitoring:
+        name: prometheus
         type: prometheus
         access: proxy
         orgId: 1
         editable: true
-        url: 'http://prom-metrics.openstack.svc.cluster.local:9090'
   grafana:
     auth.ldap:
       enabled: true