Node-Exporter: Override default image entrypoint

This updates the node-exporter chart to provide the mechanism
for overriding the default image's entrypoint, which brings it in
line with the other charts

Change-Id: Ia8f6a306a6f72d7dba37e5c5736e0f5a11ad1bf0

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

@@ -0,0 +1,26 @@
+#!/bin/sh
+{{/*
+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.
+*/}}
+
+set -ex
+
+exec /bin/node_exporter \
+  --collector.ntp \
+  --collector.ntp.server={{ .Values.conf.ntp_server_ip }} \
+  --collector.meminfo_numa \
+  --collector.bonding \
+  --collector.mountstats
+  --logtostderr

prometheus-node-exporter/templates/configmap-bin.yaml

@@ -22,6 +22,8 @@ kind: ConfigMap
 metadata:
   name: node-exporter-bin
 data:
+  node-exporter.sh: |
+{{ tuple "bin/_node-exporter.sh.tpl" . | include "helm-toolkit.utils.template" | indent 4 }}
   image-repo-sync.sh: |
 {{- include "helm-toolkit.scripts.image_repo_sync" . | indent 4 }}
 {{- end }}

prometheus-node-exporter/templates/daemonset.yaml

@@ -57,12 +57,8 @@ spec:
         - name: node-exporter
 {{ tuple $envAll "node_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.node_exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
-          args:
-            - --collector.ntp
-            - --collector.ntp.server={{ .Values.conf.ntp_server_ip }}
-            - --collector.meminfo_numa
-            - --collector.bonding
-            - --collector.mountstats
+          command:
+            - /tmp/node-exporter.sh
           ports:
             - name: metrics
               containerPort: {{ tuple "node_metrics" "internal" "metrics" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
@@ -74,6 +70,10 @@ spec:
             - name: sys
               mountPath: /host/sys
               readOnly:  true
+            - name: node-exporter-bin
+              mountPath: /tmp/node-exporter.sh
+              subPath: node-exporter.sh
+              readOnly: true
       volumes:
         - name: proc
           hostPath:
@@ -81,4 +81,8 @@ spec:
         - name: sys
           hostPath:
             path: /sys
+        - name: node-exporter-bin
+          configMap:
+            name: node-exporter-bin
+            defaultMode: 0555
 {{- end }}