IIS Rewrite very confusing - wcf

Question

concerning IIS Rewrites.
I want to change this url on my local IIS Instance
http://localhost/MySite/health?key=BczI5MyulpRLxI2kiJmIXwLOm78r3qr8z2gwcsYTGR4=&c
to redirect to this url:
http://localhost/MySite/Health.svc/BczI5MyulpRLxI2kiJmIXwLOm78r3qr8z2gwcsYTGR4=/c
As you can see I don't want the incoming request to use
Health.svc/BczI5MyulpRLxI2kiJmIXwLOm78r3qr8z2gwcsYTGR4=/c
instead to use
health?key=BczI5MyulpRLxI2kiJmIXwLOm78r3qr8z2gwcsYTGR4=&c
The Health.svc is the WCF endpoint name, so I just want /health with the key and filter parameter at the end as shown.
Whatever I put in my web config rewrite it still doesn't work. I am rather confused what bit of the url to put in, as the regex seems to be valid as I can test it in IIS and online regex validators.
<rewrite>
<rules>
<rule name="HealthRewrite" stopProcessing="true" enabled="true">
<match url="MySite\/health\?key=([0-9a-zA-Z=]+)&([a-z])" />
<action type="Rewrite" url="MySite/Health.svc/{R:1}/{R:2}" appendQueryString="false" />
</rule>
</rules>
</rewrite>
How can I get this to work? I have got the rewrite module installed as can see it in IIS an also can see the dll is registered.

Answer 1

If you want to match the value of the query string in IIS, you need to use {QUERY_STRING}. Here is a demo:
<rewrite>
<rules>
<rule name="Test">
<match url="(Service1)" />
<conditions>
<add input="{QUERY_STRING}" pattern="(key)=(.*)" />
</conditions>
<action type="Rewrite" url="Service1.svc/{C:2}" />
</rule>
</rules>
</rewrite>
This is my web.config.
This URL:
http://localhost/Service1?key=getdata
will redirect to this url:
http://localhost/Service1.svc/GetData
For your last question, why add the MySite prefix? This is because the URL in the Rewrite URL will be used as the redirect URL. Notice that it uses back-references to preserve and rearrange the original URL pieces captured during pattern match. For Rewrite, all prefixes other than localhost must be provided in the Rewrite URL.

Answer 2

I managed to get it working with going to all sorts of sites as its not obvious at all.
They key seemed to put the conditions in and then a {QUERY_STRING} with regex which can then create the {C:1} and {C:2} groups that are pushed into the new rewrite
<rewrite>
<rules>
<rule name="HealthRewrite" stopProcessing="true" enabled="true">
<match url="^health" />
<conditions logicalGrouping="MatchAll" trackAllCaptures="false">
<add input="{QUERY_STRING}" pattern="key=([0-9a-zA-Z=]+)&([a-z])" />
</conditions>
<action type="Rewrite" url="/MySite/Health.svc/{C:1}/{C:2}" appendQueryString="false"/>
</rule>
</rules>
</rewrite>
I found it confusing knowing what url to match but with a few simplified tests of just ^health I could see more easily and play around with getting the query string parameters. I had to provide the Rewrite with the /MySite/ prefix which is confusing as the match didn't need that!