Get hostname in ASP.Net on IIS

Question

Based on my question here

I am going to get the hostname in Application_Start so I have done it before something like:

if(string.IsNullOrWhiteSpace(Hostname)) 
        Hostname = Dns.GetHostName();

Based on this screenshot:

But it returns skyweb - but I want to get RND1.

The other solution to get hostname is HttpContext.Current.Request.Url.Host; but as you know I don't want get in through the pages event it is better be initiated at first go...

So what is the best way to do this?

Thanks in advance.

Edit1:

If you take a look at here you will see what I am looking for which pointed in picture, meanwhile I mentioned in this screenshot again:

I can't set this in configuration, It may be set while installing process or be set by admin of server manually.

I am looking for hostname while be set in adding new website.

Answer 1

When we add hostname and binding the applicationHost.config file get changed which located at C:\Windows\System32\inetsrv\config so per site it get some change like binding,apppool and etc, for me I see the binding for RND1 is something like :

<site name="RND1" id="3">
  <bindings>
    <binding protocol="http" bindingInformation="*:80:RND1" />
    <binding protocol="net.pipe" bindingInformation="RND1" />
    <binding protocol="net.tcp" bindingInformation="2042:RND1" />
    <binding protocol="https" bindingInformation="*:443:RND1" sslFlags="0" />
    <binding protocol="net.msmq" bindingInformation="RND1" />
   </bindings>
</site>

So we can get that applicationhost file and manipulate it but with some search I crossed to this which give some helpful info to get IIS binding at run time.

with little changes of codes I implemented it like below to get hostname:

 private static string GetHostname()
    {
        // Get the Site name 
        string siteName = HostingEnvironment.SiteName; 
        // Get the sites section from the AppPool.config
        Microsoft.Web.Administration.ConfigurationSection sitesSection =
            Microsoft.Web.Administration.WebConfigurationManager.GetSection(null, null,
                "system.applicationHost/sites");
        foreach (Microsoft.Web.Administration.ConfigurationElement site in sitesSection.GetCollection())
        {
            // Find the right Site
            if (string.Equals((string)site["name"], siteName, StringComparison.OrdinalIgnoreCase))
            { 
                // For each binding see if they are http based and return the port and protocol
                foreach (Microsoft.Web.Administration.ConfigurationElement binding in site.GetCollection("bindings"))
                {
                    var bindingInfo = (string)binding["bindingInformation"]; 
                    return bindingInfo.Split(':')[2]; 
                }
            }
        }
        return null;
    }

and using it in application_start like:

void Application_Start(object sender, EventArgs e)
    {
        if (string.IsNullOrWhiteSpace(Hostname))
            Hostname = GetHostname();
    }