ILoadBalancer does not support this case when the service instance's hostname is not equal to ip

[pengweiqhca]

Is your feature request related to a problem? Please describe.

When some service instance use special hostname rather than ip.

curl "http://127.0.0.1/xxx" -H "Host: bar.com"

Describe the solution you'd like

IServiceInstance.Uri should return scheme://ip:port/

-public virtual async Task<Uri> ResolveServiceInstanceAsync(Uri request)
+public virtual async Task ResolveServiceInstanceAsync(HttpRequestMessage request)
{
    var resolvedUri = availableServiceInstances[_random.Next(availableServiceInstances.Count)].Uri;
-   return new Uri(resolvedUri, request.PathAndQuery);
+   equest.RequestUri = new Uri(resolvedUri, request.RequestUri.PathAndQuery);
+   request.Headers.Host = resolvedUri.Host;
}

Describe alternatives you've considered

The hostname resolution result may be different with the ip, so the specified service instance cannot be accessed

Additional context

[dtillman]

Can you provide a sample app that illustrates this problem...

Thanks

[pengweiqhca]

{
  "eureka:instance": {
    "instance": {
      //"preferIpAddress": true,
      "hostName": "bar.com",
      "ipAddress": "127.0.0.1",
      "port": 80
    }
  }
}

If preferIpAddress is true, instance uri is http://127.0.0.1. if preferIpAddress is false , instance uri is http://bar.com. When my site depoly in iis, binding with *:9054:bar.com, and bar.com resolved to multiple ips, the right way is

curl "http://127.0.0.1/xxx" -H "Host: bar.com"

[jkonicki]

We will addressing with our Eureka updates in Epic #493

[TimHess]

This may not be possible with the data provided by service registrations

[TimHess]

This reads to me as a case where the app registering should set Eureka:Instance:RegistrationMethod to HostName so that the hostname will be used for the Uri and the IP address can be resolved via DNS. Please let us know if there is still a need to have both IP address and hostname specified