Annotations and checksum (#5067)

* Allow overriding service annotations.

Service annotations are a common way to allow metric discovery in
Prometheus, including the stable Prometheus chart, so it makes sense to
allow a user of this chart to override those values.

* Invalidate deployment on ConfigMap change.

Once a cloudwatch exporter is set up, most of the tweaking you'll be
doing will be to the configuration. This technique is described in the
Helm Chart Tips & Tricks documentation:

https://github.com/kubernetes/helm/blob/master/docs/charts_tips_and_tricks.md#automatically-roll-deployments-when-configmaps-or-secrets-change

* Raise chart version.

stable/prometheus-cloudwatch-exporter/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v1
 appVersion: "0.1.0"
 description: A Helm chart for prometheus cloudwatch-exporter
 name: prometheus-cloudwatch-exporter
-version: 0.1.1
+version: 0.1.2
 home: https://github.com/prometheus/cloudwatch_exporter
 sources:
 - https://github.com/prometheus/cloudwatch_exporter

stable/prometheus-cloudwatch-exporter/README.md

@@ -51,6 +51,7 @@ The following table lists the configurable parameters of the Cloudwatch Exporter
 | `service.type`              | Service type                                           | `ClusterIP`                |
 | `service.port`              | The service port                                       | `80`                       |
 | `service.targetPort`        | The target port of the container                       | `9100`                     |
+| `service.annotations`       | Custom annotations for service                         | `{}`                       |
 | `resources`                 |                                                        | `{}`                       |
 | `aws.region`                | AWS Cloudwatch region                                  | `eu-west-1`                |
 | `aws.role`                  | AWS IAM Role To Use                                    |                            |

stable/prometheus-cloudwatch-exporter/templates/deployment.yaml

@@ -20,6 +20,7 @@ spec:
         release: {{ .Release.Name }}
       annotations:
         {{ if .Values.aws.role}}iam.amazonaws.com/role: {{ .Values.aws.role }}{{ end }}
+        checksum/config: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
     spec:
       containers:
         - name: {{ .Chart.Name }}

stable/prometheus-cloudwatch-exporter/templates/service.yaml

@@ -2,6 +2,8 @@ apiVersion: v1
 kind: Service
 metadata:
   name: {{ template "prometheus-cloudwatch-exporter.fullname" . }}
+  annotations:
+{{ toYaml .Values.service.annotations | indent 4 }}
   labels:
     app: {{ template "prometheus-cloudwatch-exporter.name" . }}
     chart: {{ template "prometheus-cloudwatch-exporter.chart" . }}

stable/prometheus-cloudwatch-exporter/values.yaml

@@ -13,6 +13,7 @@ service:
   type: ClusterIP
   port: 80
   targetPort: 9100
+  annotations: {}
 
 resources: {}
   # We usually recommend not to specify default resources and to leave this as a conscious