prometheus-process-exporter: Add pod/container security context

This updates the prometheus-process-exporter chart to include the pod
security context on the pod template. This changes the pod's
user from root to the nobody user instead

This also adds the container security context to set
allowPrivilegeEscalation to false and readOnlyRootFilesystem to true

Change-Id: I623227f9f9c878a8e7745f46f2cc77f6904005fb

prometheus-process-exporter/templates/daemonset.yaml

@@ -54,8 +54,7 @@ spec:
 {{ dict "envAll" $envAll "podName" "process-exporter" "containerNames" (list "process-exporter") | include "helm-toolkit.snippets.kubernetes_mandatory_access_control_annotation" | indent 8 }}
 {{ tuple $envAll | include "helm-toolkit.snippets.release_uuid" | indent 8 }}
     spec:
-      securityContext:
-        readOnlyRootFilesystem: true
+{{ dict "envAll" $envAll "application" "metrics" | include "helm-toolkit.snippets.kubernetes_pod_security_context" | indent 6 }}
       serviceAccountName: {{ $serviceAccountName }}
 {{ if .Values.pod.tolerations.process_exporter.enabled }}
 {{ tuple $envAll "process_exporter" | include "helm-toolkit.snippets.kubernetes_tolerations" | indent 6 }}
@@ -71,6 +70,7 @@ spec:
         - name: process-exporter
 {{ tuple $envAll "process_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.process_exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
+{{ dict "envAll" $envAll "application" "metrics" "container" "process_exporter" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
           args:
             - -procnames
             - {{ .Values.conf.processes }}

prometheus-process-exporter/values.yaml

@@ -37,6 +37,14 @@ labels:
     node_selector_value: enabled
 
 pod:
+  security_context:
+    metrics:
+      pod:
+        runAsUser: 65534
+      container:
+        process_exporter:
+          allowPrivilegeEscalation: false
+          readOnlyRootFilesystem: true
   affinity:
     anti:
       type: