Application Insights OWIN extensions

This library is a set of extensions, that allow you to easily get some features normally not available for OWIN based applications out-of-the-box (but are available when using the classic ASP.NET pipeline).

Features

• Sets the common Context.Operation.Id property for all telemetries within one request (even asynchronously called dependencies)
• Pass Context.Operation.Id property between multiple dependencies request chains
• Creates Request telemetry with proper name, id and execution time
• Useable with both self-hosted and System.Web hosted OWIN applications

Installation

Required steps

Install Application Insights within the project like you would normally do. You may also want to update related nuget packages to latest versions.

Install the extensions package:

Install-Package ApplicationInsights.OwinExtensions

In your Startup class, add as a first step of the pipeline:

public class Startup
{
	public void Configuration(IAppBuilder app)
	{
		app.UseApplicationInsights();
		
		// rest of the config here...
	}
}

Cleanup the ApplicationInsights.config by removing telemetry initializers and modules with overlapping functionality.

• Microsoft.ApplicationInsights.Web.OperationCorrelationTelemetryInitializer
• Microsoft.ApplicationInsights.Web.OperationIdTelemetryInitializer
• Microsoft.ApplicationInsights.Web.OperationNameTelemetryInitializer

and also the Microsoft.ApplicationInsights.Web.RequestTrackingTelemetryModule

One last thing to do is to configure the Operation Id telemetry initializer. With XML in ApplicationInsights.config:

<TelemetryInitializers>
	<!-- other initializers ... -->
	<Add Type="ApplicationInsights.OwinExtensions.OperationIdTelemetryInitializer, ApplicationInsights.OwinExtensions"/>
</TelemetryInitializers>

or in code:

TelemetryConfiguration.Active
	.TelemetryInitializers.Add(new OperationIdTelemetryInitializer());

Possibly required steps

Note: If you are using Microsoft.Owin.Security.* middlewares, you need to restore the Operation Id context one step after the authentication middleware - otherwise the Operation Id context will be lost. This problem is most probably related to the security middleware taking advantage of the old System.Web pipeline integration and setting the stage markers. The problem will probably surface also with other middlewares using the stage markers.

// ...
app.UseOAuthBearerTokens(OAuthOptions);
// ...

// now restore the Operation Id context from the OWIN environment dictionary
app.RestoreOperationIdContext();

Advanced usage

Selectively tracing requests

You can pass a parameter to the UseApplicationInsights method specifying request filtering callback.

appBuilder.UseApplicationInsights(new RequestTrackingConfiguration
{
    ShouldTrackRequest = ctx => Task.FromResult(ctx.Request.Method != "OPTIONS")
});

Selectively tracing exceptions

You can specify filter to ignore certain exceptions. By default, OperationCancelledException is ignored if client cancelled the request. If you specify your own filter, also include the cancelled request condition.

appBuilder.UseApplicationInsights(new RequestTrackingConfiguration
{
    ShouldTrackException = ctx => async (ctx, e) => 
        await DefaultFilters.ShouldTrackException(ctx, e) && !(e is MyException)
});

Adding custom properties to telemetry

You can also extend the traced telemetry with custom properties. Note: if your custom properties are not related to the request or the response, you can alternatively specify additional TelemetryInitializer in your Application Insights telemetry configuration.

appBuilder.UseApplicationInsights(new RequestTrackingConfiguration
{
    GetAdditionalContextProperties = ctx =>
        Task.FromResult(new[] { new KeyValuePair<string, string>("Content-Type", ctx.Request.ContentType)}
            .AsEnumerable())
});

Modifying TelemetryContext with data from OwinContext

Additionally, you can enrich the telemetry context with information from the OwinContext. You can use this to modify the user context of the Request Telemetry.

appBuilder.UseApplicationInsights(new RequestTrackingConfiguration
{
    ModifyTelemetryContext = (owinContext, telemetryContext) =>
		{
			telemetryContext.User.Id = owinContext.Authentication.User.Identity.Name;
			return Task.CompletedTask;
		}
});

Passing OperationId via header

Let's presume that your system is build of many services communicating by http requests with each other . You probably would like to be able to track how the specific operation propagate through your system's components. To achieve this you should append the operation id to each request with a header. Provided middleware can acquire that id, use it with its own telemetry and then it can be passed to next component. And so on...

This behaviour is turned off by default. Following snippets present how to turn it on.

public class Startup
{
	public void Configuration(IAppBuilder app)
	{
		app.UseApplicationInsights(			
		  new OperationIdContextMiddlewareConfiguration { OperationIdFactory = IdFactory.FromHeader("X-My-Operation-Id") });
		  
		// rest of the config here...
	}
}

Example how to perform http request with appended Context.Operation.Id value:

using (var client = new HttpClient())
{
	var request = new HttpRequestMessage
	{
		Method = HttpMethod.Get,
		RequestUri = new Uri($"http://{serviceHost}:{servicePort}")
	};

	request.Headers.Add("X-My-Operation-Id", OperationContext.Get().OperationId);
	await client.SendAsync(request);
}

The OperationContext is a static class storing current request Context.Operation.Id value.

Changing how ids are generated

By default, new ids are generated as Guids. You can change that by providing delegates in OperationIdContextMiddlewareConfiguration.OperationIdFactory and RequestTrackingConfiguration.RequestIdFactory.

Operation scope and parent operation id

You can create sub-operations and manage the OperationParentId via the OperationContextScope.

using (new OperationContextScope("operationId", "parentOperationId")) 
{
	// telemetries sent here will have specified ids set
}

You should keep the same operation id for all requests, dependencies, etc. that make up a single logical operation you want to track. Change the parent operation id to create a tree of sub-operations.

If you are implementing a middleware, you may want to also save the new values in the OWIN environment dictionary, so that they can be restored via RestoreOperationIdContext. To learn more about parent operation id, see this article.

using (new OperationContextScope("operationId", "parentOperationId")) 
using (new OperationContextStoredInOwinContextScope(owinContext))
{
	// telemetries sent here will have specified ids set
}

Optional steps

You can use ComponentNameTelemetryInitializer to add ComponentName property to your telemetry. It will simplify filtering telemetries connected with specific component of your system.

TelemetryConfiguration.Active
	.TelemetryInitializers.Add(new ComponentNameTelemetryInitializer("MyComponentName"));

How this stuff works

First middleware in the pipeline establishes a new Operation Id context (Guid.NewGuid() by default). This value is stored both in OWIN environment dictionary under the ApplicationInsights.OwinExtensions.OperationIdContext key, and in the CallContext. There is the OperationIdContext class that can be used to access the current value of Operation Id from anywhere within the call context. The telemetry initializer makes use of that and sets appropriate property on the telemetries.

Contributing

If you would like to contribute, please create a PR against the develop branch.

Release notes

0.9.0

• [FEATURE] - allow modifying telemetry context before sending, see #38

0.8.1

• [FIX] - fix for dependencies issue introduced by 0.8.0, see #37

0.8.0

• [FIX] - fix for OperationCancelledException and TaskCancelledException being logged in telemetry

0.7.0

• [MAINTENANCE] - bumped dependency on Microsoft.ApplicationInsights to >= 2.0

0.6.0

• [BREAKING] - removed the IdGenerationStrategy - use OperationIdContextMiddlewareConfiguration.OperationIdFactory and RequestTrackingConfiguration.RequestIdFactory
• [BREAKING] - at least .NET 4.6.1 is required now
• [FEATURE] - parent operation id can be managed with OperationContextScope
• [FEATURE] - establishing OperationId and RequestId can be customized and based on current OWIN context

0.5.1

• [FIX] - #24 temporary fix for operation parent id not set on telemetry

0.5.0

• [BREAKING] (possibly) - UseApplicationInsights now accepts an instance of RequestTrackingConfiguration instead of separate configuration parameters. Old overload has been deprecated
• [FEATURE] - IOwinContext is passed to request filter and additional properties extractor delegates
• [FEATURE] - request filter and additional properties extractor delegates are now async

0.4.1

• [FIX] Fixed #17 - incorrect logging when exception thrown from downstream OWIN pipeline

0.4.0

• [FEATURE] It is now possible to add custom properties to the logged request telemetry by providing a delegate in UseApplicationInsights

0.3.0

• [FEATURE] It is now possible to filter logged request telemetries by providing a delegate in UseApplicationInsights