Correlation doesn't work for localhost => breaks Azure Service Fabric's built-in reverse proxy

[zakimaksyutov]

Built-in Azure Service Fabric's reverse proxy is access through localhost. Due to this logic (line about localhost) AI SDK doesn't do correlation:

	<Add Type="Microsoft.ApplicationInsights.DependencyCollector.DependencyTrackingTelemetryModule, Microsoft.AI.DependencyCollector">
		<ExcludeComponentCorrelationHttpHeadersOnDomains>
			<!-- 
    Requests to the following hostnames will not be modified by adding correlation headers.         
    Add entries here to exclude additional hostnames.
    NOTE: this configuration will be lost upon NuGet upgrade.
    -->
			<Add>core.windows.net</Add>
			<Add>core.chinacloudapi.cn</Add>
			<Add>core.cloudapi.de</Add>
			<Add>core.usgovcloudapi.net</Add>
			<Add>localhost</Add>
			<Add>127.0.0.1</Add>
		</ExcludeComponentCorrelationHttpHeadersOnDomains>
		<IncludeDiagnosticSourceActivities>
			<Add>Microsoft.Azure.EventHubs</Add>
			<Add>Microsoft.Azure.ServiceBus</Add>
		</IncludeDiagnosticSourceActivities>
	</Add>

According to @lmolkova this logic isn't required anymore. Let's remove it?

[lmolkova]

Warning!

Do NOT do this workaround if you have Microsoft.ApplicationInsights.DependencyCollector 2.6.0 or previous versions and run Azure Storage Emulator on localhost! It results in issue sending requests to storage.

Workaround

ASP.NET (classic) - ApplicationInsights.Web SDK from 2.7.0-beta1 to 2.9.0-beta2

Users can enable correlation on localhost by removing

<Add>localhost</Add>
<Add>127.0.0.1</Add>

AspNetCore (ApplicaitonInsights.AspNetCore from 2.4.0-beta1 to 2.6-beta2) users can do

public void ConfigureServices(IServiceCollection services)
{
    ...

    services.AddApplicationInsightsTelemetry();
    services.ConfigureTelemetryModule<DependencyTrackingTelemetryModule>((m, _) =>
    {
        m.ExcludeComponentCorrelationHttpHeadersOnDomains.Remove("localhost");
        m.ExcludeComponentCorrelationHttpHeadersOnDomains.Remove("127.0.0.1");
    });
}

[TimothyMothra]

@lmolkova can we close this?