Example to set up injection of PROXY_CONFIG into a gateway to allow non istio-system gateways

gateway-injection.yaml

apiVersion: operator.istio.io/v1alpha1
kind: IstioOperator
metadata:
  name: istio
spec:
  revision: alt
  components:
    ingressGateways:
    - name: istio-ingressgateway
      enabled: true
    - namespace: other
      name: gateway
      enabled: true
      k8s:
        service:
          ports:
          - port: 80
            targetPort: 8080
            name: http
  values:
    gateways:
      istio-ingressgateway:
        injectionTemplate: gateway
    sidecarInjectorWebhook:
      templates:
        gateway: |
          spec:
            containers:
            - name: istio-proxy
              env:
              - name: PROXY_CONFIG
                value: {{ protoToJSON .ProxyConfig | quote }}