Route fails to match if host header contains a port domains omits port

[taion809]

Title: Route fails to match if host header contains a port but domains omits port

Description:
Port numbers in an http host header affect route matching in envoy in a way that is unexpected as a user. When issuing an http request, as a user, I would expect curl service:80 to be matched as if I had issued the following request curl service. What happens now is that if the list of domains in a virtual host does not contain both the domain with and without a port it will not be matched and return a 404.

Configuration

admin:
  access_log_path: /tmp/admin_access.log
  address:
    socket_address: { address: 127.0.0.1, port_value: 9901 }

static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 80 }
    filter_chains:
    - filters:
      - name: envoy.http_connection_manager
        config:
          stat_prefix: ingress_http
          route_config:
            name: local_route
            virtual_hosts:
            - name: local_service
              domains: ["envoy.localhost"]
              routes:
              - match: { prefix: "/" }
                route: { host_rewrite: www.google.com, cluster: service_google }
          http_filters:
          - name: envoy.router
  clusters:
  - name: service_google
    connect_timeout: 0.25s
    type: LOGICAL_DNS
    # Comment out the following line to test on v6 networks
    dns_lookup_family: V4_ONLY
    lb_policy: ROUND_ROBIN
    hosts: [{ socket_address: { address: google.com, port_value: 443 }}]
    tls_context: { sni: www.google.com }

Repro steps:
Success:

curl -v envoy.localhost:80

Failure:

curl -v envoy.localhost:80 -H 'Host: envoy.localhost:80'

The reason this succeeds is that curl will drop the port number from the host header when it is a well-known port like port 80. This is not consistent across all http clients of course, prometheus for example may issue a scrape request with the host header set to include a port number.

I understand this is not necessarily a bug but it does break with existing proxies and existing expectations.

[mattklein123]

@taion809 this is a duplicate of #886 I think? Are you OK with tracking in that issue?

[taion809]

ah cool sorry, i actually searched the issues first before posting so I must have missed that 🤣