redirect subdomains from one domain to another domain's subdomain in iis with url rewrite

Question

I want to redirect subdomains that come to iis to subdomains in localhost:port that my dotnet core application is running.

Simply i want to redirect like this:

xyz.example.com => xyz.localhost:4000

john.example.com => john.localhost:4000

test.example.com => test.localhost:4000

example.com => localhost:4000 (no subdomain address redirects to localhost:4000)

How can I do this with url rewrite rules is iis?

Edit:

there are some solutions for one subdomain (like this question) but my question is more general to redirect all subdomain from one domain to corresponding subdomain in another domain.

Possible duplicate of Redirect Subdomain URL to another SubDomain in IIS — NightOwl888
No, this is not duplicate, because that question that you mentioned is very simpler than my problem. I need dynamically rewrite all subdomains, not only samples I wrote. — Hussein Jahanbakhsh

CodeFuller CodeFuller · Accepted Answer · 2018-02-18T13:01:08

Here is the rule that performs redirect you are asking for:

<rewrite>
    <rules>
        <rule name="Test Rule" stopProcessing="true">
            <match url=".*" />
            <conditions>
                <add input="{HTTP_HOST}" pattern="^((.+.)?)example.com" />
            </conditions>
            <action type="Redirect" url="http://{C:1}localhost:4000{REQUEST_URI}" appendQueryString="false" />
        </rule>
    </rules>
</rewrite>

It's pretty straightforward:

<match url=".*" /> matches any URL. Whether requested URL is in example.com domain is checked in later condition. match section is useless for our case because it operates with the URL part without a hostname (after first '/').
Condition <add input="{HTTP_HOST}" pattern="^((.+.)?)example.com" /> matches domains like xyz.example.com or example.com. If condition is matched, capture group {C:1} will contain xyz. for xyz.example.com and empty string for example.com, which will be used further.
<action type="Redirect" url="http://{C:1}localhost:4000{REQUEST_URI}" appendQueryString="false" />

The result URL is built as http://{C:1}localhost:4000{REQUEST_URI}. {C:1} will hold subdomain name as said above and {REQUEST_URI} contains URL part after hostname. We also set appendQueryString to false because query is a part of {REQUEST_URI}.

You should add this <rewrite> section to site web.config under <system.webServer>. You could also configure it manually from IIS Configuration Manager. Here is a screenshot of such configuration:

Finally, here is a set of test that demonstrates how urls are changed:

[TestCase("http://xyz.example.com", "http://xyz.localhost:4000/")]
[TestCase("http://xyz.example.com/some/inner/path", "http://xyz.localhost:4000/some/inner/path")]
[TestCase("http://xyz.example.com/some/inner/path?param1=value1&param2=value2", "http://xyz.localhost:4000/some/inner/path?param1=value1&param2=value2")]
[TestCase("http://example.com", "http://localhost:4000/")]
[TestCase("http://example.com/some/inner/path", "http://localhost:4000/some/inner/path")]
[TestCase("http://example.com/some/inner/path?param1=value1&param2=value2", "http://localhost:4000/some/inner/path?param1=value1&param2=value2")]
public void CheckUrlRedirect(string originalUrl, string expectedRedirectUrl)
{
    using (var httpClient = new HttpClient(new HttpClientHandler {AllowAutoRedirect = false}))
    {
        var response = httpClient.GetAsync(originalUrl).Result;

        Assert.AreEqual(HttpStatusCode.MovedPermanently, response.StatusCode);
        var redirectUrl = response.Headers.Location.ToString();
        Assert.AreEqual(expectedRedirectUrl, redirectUrl);
    }
}

redirect subdomains from one domain to another domain's subdomain in iis with url rewrite

Edit:

1 Answers