Getting hostname in MVC controller constructor

Question

Is it possible to get the current hostname from the controller constructor?

Both the Request and HttpContext objects are null, so Request.Url yields nothing.

public class HomeController : Controller
{
    private readonly MyEntities _entities;

    public HomeController()
    {
        //
        var hostname = Request.Url;
        if (hostname.Contains("localhost")) EFConnectionStringName="localhost";
        else EFConnectionStringName="default";
        _entities = new MyEntities(EFConnectionStringName);
    }
...

The greater problem I am trying to solve here is to choose a connection string for Entity Framework based upon the hostname. Ideas?

See this: http://stackoverflow.com/questions/541635/how-do-i-find-fully-qualified-hostname-of-my-machine-in-c — Tomas Kubes, Nov 06 '13 at 07:48
Taking that it says "localhost" in your code I suspect you want to use a seperate connection when you are debugging? Why not just use a web.debug.config file? See: http://blogs.msdn.com/b/webdev/archive/2009/05/04/web-deployment-web-config-transformation.aspx — mortb, Nov 06 '13 at 07:51
There will be a few more hostnames that need to be included for different environments, maybe 6 in total. Yes, I'm aware this is not best practice, but the decision was made and I'm following orders. — Ben Power, Nov 06 '13 at 10:58

haim770 · Accepted Answer · 2015-04-16T15:05:21.030

24

Request is indeed null during the construction of your Controller. Try this instead:

protected override void Initialize(System.Web.Routing.RequestContext requestContext)
{
    var hostname = requestContext.HttpContext.Request.Url.Host;

    // do something based on 'hostname' value
    // ....

    base.Initialize(requestContext);
}

Also, please note that Request.Url will not return the hostname but a Uri object from which you can extract the hostname using Url.Host.

See MSDN.

edited Apr 16 '15 at 15:05

answered Nov 06 '13 at 08:13

haim770

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Is this no longer possible in ASP.NET 5 preview? – tofutim Sep 21 '15 at 18:18

oxfn · Answer 2 · 2014-01-10T11:04:39.220

8

Try this:

public class HomeController : Controller
{
    protected override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        base.OnActionExecuting(filterContext);
        Debug.Print("Host:" + Request.Url.Host); // Accessible here
        if (Request.Url.Host == "localhost")
        {
            // Do what you want for localhost
        }
    }
}

Note, that Request.Url is an Uri object, so you should check Request.Url.Host

edited Jan 10 '14 at 11:04

answered Nov 06 '13 at 07:56

oxfn

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Beautiful, thanks for your reply! I'm sorry I can only mark one answer as accepted. Both yours and haim770's answers did the job perfectly. – Ben Power Nov 07 '13 at 00:03
If someone happens to be looking a way of blocking requests based on localhost (e.g, a controller only for local tests), it is possible to write the follow to prevent actions from being executed: `filterContext.Result = RedirectToAction("Index", "Home"); Dispose(); //Important` – Reuel Ribeiro Jun 20 '16 at 12:51

score 0 · Answer 3 · answered Mar 17 '16 at 13:05

0

Request URL's host doesn't necessarily have to match the hosting server name. For example if you're using DNS CNAMEs or loadbalancers.

If you'd like the machine name of the server hosting the code, try this in your controller action:

string hostingMachineName = HttpContext.ApplicationInstance.Server.MachineName;

answered Mar 17 '16 at 13:05

Brian Adriance

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3

Thanks that's what I'm looking for because of the load balancing scenario you mentioned, unfortunately my HttpContext doesn't have the ApplicationInstance object. What am I missing? I'm using ASP.net Core 1.1.0, is this only available in regular the .net framework? – ArgisIsland Jun 16 '17 at 16:20

score 0 · Answer 4 · answered Jan 09 '21 at 03:53

0

current pc host :-
string PCName = Dns.GetHostEntry(Request.ServerVariables["REMOTE_ADDR"]).HostName;   

server host :-
String hostName = Dns.GetHostName();

answered Jan 09 '21 at 03:53

chandu komati

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Getting hostname in MVC controller constructor

4 Answers4