Add optional config reloader

Signed-off-by: Alex Ramos <aramos@asserts.ai>

charts/alertmanager/Chart.yaml

@@ -6,7 +6,7 @@ icon: https://raw.githubusercontent.com/prometheus/prometheus.github.io/master/a
 sources:
   - https://github.com/prometheus/alertmanager
 type: application
-version: 0.1.4
+version: 0.1.5
 appVersion: v0.21.0
 maintainers:
   - name: monotek

charts/alertmanager/templates/statefulset.yaml

@@ -23,6 +23,19 @@ spec:
       securityContext:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       containers:
+        {{- if and (.Values.configmapReload.enabled) (.Values.config) }}
+        - name: {{ .Chart.Name }}-{{ .Values.configmapReload.name }}
+          image: "{{ .Values.configmapReload.image.repository }}:{{ .Values.configmapReload.image.tag }}"
+          imagePullPolicy: "{{ .Values.configmapReload.image.pullPolicy }}"
+          args:
+            - --volume-dir=/etc/alertmanager
+            - --webhook-url=http://127.0.0.1:{{ .Values.service.port }}/-/reload
+          resources:
+            {{ toYaml .Values.configmapReload.resources | indent 12 }}
+          volumeMounts:
+            - name: config
+              mountPath: /etc/alertmanager
+        {{- end }}
         - name: {{ .Chart.Name }}
           securityContext:
             {{- toYaml .Values.securityContext | nindent 12 }}
@@ -51,8 +64,7 @@ spec:
           volumeMounts:
             {{- if .Values.config }}
             - name: config
-              mountPath: /etc/alertmanager/alertmanager.yml
-              subPath: alertmanager.yml
+              mountPath: /etc/alertmanager
             {{- end }}
             - name: storage
               mountPath: /alertmanager

charts/alertmanager/values.yaml

@@ -98,3 +98,27 @@ config:
     group_interval: 5m
     receiver: default-receiver
     repeat_interval: 3h
+
+## Monitors ConfigMap changes and POSTs to a URL
+## Ref: https://github.com/jimmidyson/configmap-reload
+##
+configmapReload:
+  ## If false, the configmap-reload container will not be deployed
+  ##
+  enabled: false
+
+  ## configmap-reload container name
+  ##
+  name: configmap-reload
+
+  ## configmap-reload container image
+  ##
+  image:
+    repository: jimmidyson/configmap-reload
+    tag: v0.4.0
+    pullPolicy: IfNotPresent
+
+  ## configmap-reload resource requests and limits
+  ## Ref: http://kubernetes.io/docs/user-guide/compute-resources/
+  ##
+  resources: {}