Remotely connect to .net core self hosted web api

问题:

I have a simple .net core web api with one action:

[Route("[action]")]
public class APIController : Controller
{
    // GET api/values
    [HttpGet]
    public string Ping()
    {
        return DateTime.Now.ToString();
    }
}

If I run this via dotnet run I get

Hosting environment: Production
Content root path: C:\Users\xxx\Documents\Visual Studio 2015\Projects\SelfHostTest\src\SelfHostTest
Now listening on: http://localhost:5000
Application started. Press Ctrl+C to shut down.

Going to the browser and typing in http://localhost:5000/ping results in a successful return of the current time. However going to a remote machine (same LAN) and trying to access the service via http://odin:5000/ping results in a 404 error. (Odin is the name of the machine running the web api in a console via dotnet run).

Both server (and client!) firewalls are turned off. I can ping "odin" successfully.

Any ideas what simple step I am missing here. I've tried this at home and at work with no success.

回答1:

My guess is that the issue isn't in your controller, it is in program.cs. You need to modify the construction of your WebHost

var host = new WebHostBuilder()
.UseKestrel()
.UseContentRoot(Directory.GetCurrentDirectory())
.UseUrls("http://localhost:5000", "http://odin:5000", "http://192.168.1.2:5000")
.UseIISIntegration()
.UseStartup<Startup>()
.Build();

Unless you add the UseUrls line, Kestrel isn't going to listen outside of localhost. This makes sense, because in a normal situation Kestrel will be sitting behind a reverse proxy like IIS or NGNIX and doesn't need to bind to external URLs.

回答2:

You can simply do the following to create your WebHost, this will allow remote connections to kestrel.

var host = WebHost.CreateDefaultBuilder(args)
                .UseUrls("http://0.0.0.0:80")
                .UseStartup<Startup>()
                .Build();

After using the following code I still wasn't able to access my API remotely, I had to disable the network adapters created by Docker in the windows control panel (Control Panel\Network and Internet\Network Connections)

回答3:

In my case (.NET core 2.1) I had to modify the Properties/launchSettings.json file.

Set the applicationUrl to a list of allowed urls separated by semicolons like this

"applicationUrl": "https://localhost:5001;http://odin:5000"

Hope this helps someone out there.

回答4:

The best way is to adjust the launchSettings.json, which is located inside the Properties folder.

Change

"applicationUrl": "https://localhost:5001"

to

"applicationUrl": "https://0.0.0.0:5001"

This allows the Kestrel Web Server to listen for traffic from all Network Interfaces.

I wrote a detailed response here.

回答5:

Another way to solve this problem is editing "applicationhost.config" file. in project folder -> .vs (Hidden folder) -> config open "applicationhost.config" file. Under sites section, site name="your project name" in Bindings node add another binding and change localhost with your "IP/Domain" on "bindingInformation", like This:

<site name="project_name" id="2">
    <application path="/" applicationPool="Clr4IntegratedAppPool">
     <virtualDirectory path="/" physicalPath="D:\Projects\project_directory" />
    </application>
    <bindings>
     <binding protocol="http" bindingInformation="*:5000:localhost" />
     <binding protocol="http" bindingInformation="*:5000:192.168.1.2" />
     <binding protocol="http" bindingInformation="*:5000:odin" />
    </bindings>
</site>

remember Visual Studio must be run as Administrator.

回答6:

There is a more accurate way when there are multi IP addresses available on the local machine. Connect a UDP socket and read its local endpoint:

string localIP;
using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, 0))
{
    socket.Connect("8.8.8.8", 65530);
    IPEndPoint endPoint = socket.LocalEndPoint as IPEndPoint;
    localIP = endPoint.Address.ToString();
}