title: Update HOST header in Envoy proxy
body: <p>Hello people I have an architecture where I want to route my requests from Envoy Proxy to nginx proxy. as we know that Nginx works on HOST header matching to route its request. I'm having trouble setting the host header while forwarding the request from Envoy to Nginx. I have the following config</p>
  <p>LDS.config</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: listener_0
    address:
      socket_address:
        address: 0.0.0.0
        port_value: 8443
    filter_chains:
    - filters:
        name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          codec_type: HTTP1
          stat_prefix: ingress_http
          http_filters:
          - name: envoy.router
          route_config:
            name: local_route
            virtual_hosts:
            - name: app
              domains:
              - "some.domain.com"
              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: test-cluster
                  host_rewrite_literal: "mydns.com"
      transport_socket:
        name: envoy.transport_sockets.tls
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.transport_sockets.tls.v3.DownstreamTlsContext
          common_tls_context:
            tls_certificates:
              certificate_chain: { filename: "/etc/ssl/merged_certificate.crt" }
              private_key: { filename: "/etc/ssl/key.key" }</code></pre>
  </div>
  </div>
  </p>
  <p>CDS.config</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>resources:
  - "@type": type.googleapis.com/envoy.config.cluster.v3.Cluster
    name: test-cluster
    connect_timeout: 30s
    type: static
    load_assignment:
      cluster_name: test-cluster
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: my_private_ip_address
                port_value: 443</code></pre>
  </div>
  </div>
  </p>
  <p>I have tried the auto_host_rewrite but found that it does not works with static cluster type. but it does not updates with host_literal too.</p>