{{- if .MatchScheme }}
    match:
    - scheme:
        exact: {{.MatchScheme}}
    headers:
      request:
        add:
          istio-custom-header: user-defined-value
{{- end }}
---
`

func httpVirtualService(gateway, host string, port int) string {
	return tmpl.MustEvaluate(httpVirtualServiceTmpl, struct {
		Gateway            string
		VirtualServiceHost string
		DestinationHost    string
		Port               int