Node-Exporter: allows to set collectors enable/disable

This PS allows to set collectors enable/disable using values.
_node-exporter.sh.tpl makes collectors-list from values.yaml.

Change-Id: Iba2cf4d8304f2405db394fbb6fee58119eab13fc

helm-toolkit/templates/utils/_joinListWithPrefix.tpl

@@ -0,0 +1,34 @@
+{/*
+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.
+*/}}
+
+{{/*
+abstract: |
+  Joins a list of prefixed values into a space seperated string
+values: |
+  test:
+    - foo
+    - bar
+usage: |
+  {{ tuple "prefix" .Values.test | include "helm-toolkit.utils.joinListWithPrefix" }}
+return: |
+  prefixfoo prefixbar
+*/}}
+
+{{- define "helm-toolkit.utils.joinListWithPrefix" -}}
+{{- $prefix := index . 0 -}}
+{{- $local := dict "first" true -}}
+{{- range $k, $v := index . 1 -}}{{- if not $local.first -}}{{- " " -}}{{- end -}}{{- $prefix -}}{{- $v -}}{{- $_ := set $local "first" false -}}{{- end -}}
+{{- end -}}

prometheus-node-exporter/templates/bin/_node-exporter.sh.tpl

@@ -18,9 +18,6 @@ limitations under the License.
 set -ex
 
 exec /bin/node_exporter \
-  --collector.ntp \
-  --collector.ntp.server={{ .Values.conf.ntp_server_ip }} \
-  --collector.meminfo_numa \
-  --collector.bonding \
-  --collector.mountstats
-  --logtostderr
+  {{ tuple "--collector." .Values.conf.collectors.enable | include "helm-toolkit.utils.joinListWithPrefix" }} \
+  {{ tuple "--no-collector." .Values.conf.collectors.disable | include "helm-toolkit.utils.joinListWithPrefix" }} \
+  --collector.ntp.server={{ .Values.conf.ntp_server_ip }}

prometheus-node-exporter/values.yaml

@@ -149,3 +149,10 @@ manifests:
 
 conf:
   ntp_server_ip: 127.0.0.1
+  collectors:
+    enable:
+      - ntp
+      - meminfo_numa
+      - bonding
+      - mountstats
+    disable: