Search code examples
nginxdevopsenvoyproxy

Update HOST header in Envoy proxy

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

LDS.config

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" }

CDS.config

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

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.

Solution

  • it turns out that the config is working exactly as expected. I was looking at wrong header to verify it in the NGINX access logs. lesson learned.