elasticsearch-exporter: Add security context for exporter pod/container

This adds the security context snippet for the elasticsearch
prometheus exporter container to set allowPrivilegeEscalation to false
and readOnlyRootFilesystem to true

Change-Id: Ia80aa9cfc837073fae0a884de5245764147d7ded

elasticsearch/templates/monitoring/prometheus/exporter-deployment.yaml

@@ -52,8 +52,7 @@ spec:
         - name: elasticsearch-exporter
 {{ tuple $envAll "prometheus_elasticsearch_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
-          securityContext:
-            allowPrivilegeEscalation: false
+{{ dict "envAll" $envAll "application" "elasticsearch_exporter" "container" "elasticsearch_exporter" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
           command:
             - /tmp/elasticsearch-exporter.sh
             - start

elasticsearch/values.yaml

@@ -116,9 +116,14 @@ pod:
       elasticsearch-data: localhost/docker-default
     elasticsearch-client:
       elasticsearch-client: localhost/docker-default
-  user:
+  security_context:
     elasticsearch_exporter:
-      uid: 99
+      pod:
+        runAsUser: 99
+      container:
+        elasticsearch_exporter:
+          allowPrivilegeEscalation: false
+          readOnlyRootFilesystem: true
   affinity:
       anti:
         type: