I am trouble shooting an inbound 3rd party service and I want to log all inbound headers. As I dont know what headers I am receiving I cant use log analytics to capture headers.

I would like to use a mock response on APIM to print all inbound headers as a response message.

I have created the policy:

<policies>
    <inbound>
        <base />
        <set-variable name="HostName" value="@{
            string [] HostNameHeader;
            
            context.Request.Headers.TryGetValue("Host", out HostNameHeader);    

            return HostNameHeader[0];
        }" />
        <return-response>
            <set-status code="200" />
            <set-body>"@{context.Variables["HostName"]}"</set-body>
        </return-response>
        <mock-response status-code="200" content-type="application/json" />
    </inbound>
    <backend>
        <base />
    </backend>
    <outbound>
        <base />
    </outbound>
    <on-error>
        <base />
    </on-error>
</policies>

My response message is returning the text “@{context.Variables[“HostName”]}” rather than the the expected headers.