Helm-toolkit: Add snippet template for kubernetes probes

This adds a basic helm-toolkit snippet template for adding
kubernetes liveness and readiness probes to a container. This adds
flexibility by defining the probes contents via values overrides
wholesale

Change-Id: I0862ae59c87b8c0c4e2412030b1801bceb3e3c99
Signed-off-by: Pete Birley <pete@port.direct>

helm-toolkit/templates/snippets/_kubernetes_probes.tpl

@@ -0,0 +1,57 @@
+{{/*
+Copyright 2019 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: |
+  Renders kubernetes liveness and readiness probes for containers
+values: |
+  pod:
+    probes:
+      api:
+        default:
+          readiness:
+            enabled: true
+            params:
+              initialDelaySeconds: 30
+              timeoutSeconds: 30
+usage: |
+  {{- define "probeTemplate" }}
+  httpGet:
+    path: /status
+    port: 9090
+  {{- end }}
+  {{ dict "envAll" . "component" "api" "container" "default" "type" "readiness" "probeTemplate" (include "probeTemplate" . | fromYaml) | include "helm-toolkit.snippets.kubernetes_probe" }}
+return: |
+  readinessProbe:
+    httpGet:
+      path: /status
+      port: 9090
+    initialDelaySeconds: 30
+    timeoutSeconds: 30
+*/}}
+
+{{- define "helm-toolkit.snippets.kubernetes_probe" -}}
+{{- $envAll := index . "envAll" -}}
+{{- $component := index . "component" -}}
+{{- $container := index . "container" -}}
+{{- $type := index . "type" -}}
+{{- $probeTemplate := index . "probeTemplate" -}}
+{{- $probeOpts := index $envAll.Values.pod.probes $component $container $type -}}
+{{- if $probeOpts.enabled -}}
+{{- $probeOverides := index $probeOpts "params" | default dict -}}
+{{ dict ( printf "%sProbe" $type ) (mergeOverwrite $probeTemplate $probeOverides ) | toYaml }}
+{{- end -}}
+{{- end -}}