OpenTelemetry is becoming THE standard of telemetry instrumentation. And thanks to the Azure Monitor OpenTelemetry Exporter we can keep using Application Insights as our tool of choice. In this post I'll walk you through the steps to link your OpenTelemetry enabled ASP.NET core application to Azure Monitor Application Insights.
Important to mention is that this feature is still in preview!
At the moment of writing distributed tracing and metrics are supported but some of the other features that we like from the Application Insights SDK are not available(yet).
What is not supported?
I copied the list from the documentation:
- Live Metrics
- Logging API (like console logs and logging libraries)
- Profiler
- Snapshot Debugger
- Azure Active Directory authentication
- Autopopulation of Cloud Role Name and Cloud Role Instance in Azure environments
- Autopopulation of User ID and Authenticated User ID when you use the Application Insights JavaScript SDK
- Autopopulation of User IP (to determine location attributes)
- Ability to override Operation Name
- Ability to manually set User ID or Authenticated User ID
- Propagating Operation Name to Dependency Telemetry
- Instrumentation libraries support on Azure Functions
- Status supports statuscode(unset,ok,error) and status-description. "Status Description" is ignored by Azure Monitor Exporters.
Add Azure Monitor OpenTelemetry Exporter to your ASP.NET Core application
Now that we now what isn’t available yet, let’s focus on what we can do and see how we can start instrumenting our ASP.NET Core application using OpenTelemetry.
Let’s start by adding the necessary Nuget packages:
dotnet add package --prerelease Azure.Monitor.OpenTelemetry.Exporter
We also add some extra packages to include extra instrumentation specific for ASP.NET Core:
dotnet add package --prerelease OpenTelemetry.Extensions.Hosting dotnet add package --prerelease OpenTelemetry.Instrumentation.AspNetCore dotnet add package --prerelease OpenTelemetry.Instrumentation.Http dotnet add package --prerelease OpenTelemetry.Instrumentation.SqlClient
Now that we have all the packages we need, we can add the necessary instrumentation code:
We specified a servicename and version and added some extra attributes. But let’s take advantage of the extra instrumentation libraries we added and extend the configuration a little bit:
Last thing we need to add is the Azure Monitor OpenTelemetry exporter itself. Here we need to specify our Applications Insights connection string:
If we now run our application, our instrumentation data should be send to Application Insights.
More information: Enable Azure Monitor OpenTelemetry for .NET, Node.js, and Python applications - Azure Monitor | Microsoft Learn