Add API to control IPEndPoint of HTTP request (like ServicePoint.BindIPEndPointDelegate)

[mstefarov]

I've got a few .NET services that run on machines with multiple IP addresses, and they need to occasionally send HTTP requests from specific IPs. Currently I use HttpWebRequest with a custom ServicePoint.BindIPEndPointDelegate and it works great. I'm hoping to port this service to .NET Core/Standard, but can't find any equivalent functionality in HttpClient/HttpClientHandler.

Is there any way to control local IP to which HttpClient/HttpClientHandler binds? Any workarounds or plans to add this functionality? This is the only thing holding back my porting efforts.

[davidsh]

but can't find any equivalent functionality in HttpClient/HttpClientHandler.

There is no equivalent functionality in HttpClient/HttpClientHandler.

In addition, on .NET Core, the ServicePoint.BindIPEndPointDelegate does not function. That is because the HTTP stack on .NET Core uses a different architecture and is not possible to implement that functionality.

[mstefarov]

Hmm. I figured if System.Net.Sockets.Socket had a working cross-platform LocalEndPoint property, then perhaps it would be possible to implement the same for HttpClientHandler. If not, can you think of any workaround (e.g. setting up a proxy, a custom IHttpFilter, a custom HttpClientHandler, etc)? If not, please consider adding some extension points here in the future. There are several good use-cases for having multiple IPs on one machine.

[stephentoub]

I figured if System.Net.Sockets.Socket had a working cross-platform LocalEndPoint property, then perhaps it would be possible to implement the same for HttpClientHandler.

Today HttpClient in .NET Core is not built on top of System.Net.Sockets; rather on Windows it's built on top of the native WinHttp and on Unix on top of the native libcurl. We are investigating having a managed implementation in the future that would be built on Sockets, at which point it's possible we could make this work, but that's not going to happen for 2.0.
cc: @geoffkizer

[siberianguy]

Is there an update on this issue? We're stuck not being able to explicitly specify an ip address for a request

[stephentoub]

Closing in favor of https://github.com/dotnet/corefx/issues/23426.