The zabbix-proxy template in the Kubernetes Helm chart does not support adding sidecar containers via extraContainers configuration, unlike other components (zabbix-server, zabbix-agent).

  This enhancement adds support for defining extra containers in the proxy pod, enabling use cases like:
  - Running Zabbix Agent 2 as a sidecar for direct database monitoring
  - Adding auxiliary monitoring containers
  - Extending proxy functionality without separate deployments

  CHANGES:
  1. Modified: templates/zabbix-proxy.yaml
     - Added: {{- if .Values.zabbixProxy.extraContainers }} block after main container definition
     - Allows rendering additional containers defined in values.yaml

  2. Modified: values.yaml
     - Added: zabbixProxy.extraContainers field (default empty array)
     - Added: Documentation with example for Agent2 sidecar

  EXAMPLE USE CASE:
  Monitoring CloudNativePG PostgreSQL directly via Agent2 sidecar:

  zabbixProxy: 
    extraContainers: 
    - name: zabbix-agent2
      image: zabbix/zabbix-agent2:alpine-7.0.17
      ports: 
      - containerPort: 10050
      env: 
      - name: ZBX_HOSTNAME
        value: "pg-monitor-agent"
      - name: ZBX_SERVER_ACTIVE
        value: "localhost:10051"

BENEFITS:
  - Eliminates need for separate agent deployments
  - Simplifies proxy pod architecture
  - Consistency with other Helm chart components
  - Enables advanced monitoring scenarios with minimal complexity

  PATCH ATTACHED:

=== File 1: templates/zabbix-proxy.yaml ===

  @@ -73,6 +73,9 @@ spec: 
                 value: "5"
               \{{- end }}
               \{{- end }}
  +      \{{- if .Values.zabbixProxy.extraContainers }}
  +\{{ toYaml .Values.zabbixProxy.extraContainers | indent 8 }}
  +      \{{- end }}
         \{{- if .Values.zabbixProxy.image.pullSecrets }}
         imagePullSecrets: 
   \{{ toYaml .Values.zabbixProxy.image.pullSecrets | indent 6 }}

  === File 2: values.yaml ===

  @@ -187,6 +187,21 @@ zabbixProxy: 
       ##
       subPath: ""

  +  ## Extra containers to add to Zabbix proxy pod (e.g., sidecars for monitoring)
  +  ## Example: add Zabbix Agent2 sidecar for PostgreSQL monitoring
  +  ## extraContainers: 
  +  ##   - name: zabbix-agent2
  +  ##     image: zabbix/zabbix-agent2:alpine-7.0.17
  +  ##     ports: 
  +  ##       - containerPort: 10050
  +  ##         name: zabbix-agent
  +  ##     env: 
  +  ##       - name: ZBX_HOSTNAME
  +  ##         value: "cnpg-monitor-agent"
  +  ##       - name: ZBX_SERVER_ACTIVE
  +  ##         value: "localhost:10051"
  +  extraContainers: []
  +
   ## **Zabbix agent** configurations
   zabbixAgent: 
     ## Enable use of Zabbix agent

  Summary of changes:
  - Templates/zabbix-proxy.yaml: Added 3 lines to render extraContainers after the main proxy container
  - values.yaml: Added extraContainers: [] field with documentation and example for Agent2 sidecar

  Both changes are minimal, non-breaking (default empty array), and follow existing patterns in the chart (like zabbixServer.extraContainers).