Using the OpenTelemetry.AutoInstrumentation NuGet packages

Use the NuGet packages in the following scenarios:

1. Simplify deployment. For example, a container running a single application.
2. Support instrumentation of self-contained applications.
3. Facilitate developer experimentation with automatic instrumentation through NuGet packages.
4. Solve version conflicts between the dependencies used by the application and the automatic instrumentation.

Limitations

While NuGet packages are a convenient way to deploy automatic instrumentation, they can’t be used in all cases. The most common reasons for not using NuGet packages include the following:

1. You can’t add the package to the application project. For example, the application is from a third party that can’t add the package.
2. Reduce disk usage, or the size of a virtual machine, when multiple applications to be instrumented are installed in a single machine. In this case you can use a single deployment for all .NET applications running on the machine.
3. A legacy application that can’t be migrated to the SDK-style project.

Using the NuGet packages

To automatically instrument your application with OpenTelemetry .NET add the OpenTelemetry.AutoInstrumentation package to your project:

dotnet add [<PROJECT>] package OpenTelemetry.AutoInstrumentation

If the application references packages that can be instrumented, but, require other packages for the instrumentation to work the build will fail and prompt you to either add the missing instrumentation library or to skip the instrumentation of the corresponding package:

~packages/opentelemetry.autoinstrumentation.buildtasks/1.6.0/build/OpenTelemetry.AutoInstrumentation.BuildTasks.targets(29,5): error : OpenTelemetry.AutoInstrumentation: add a reference to the instrumentation package 'MongoDB.Driver.Core.Extensions.DiagnosticSources' version 1.4.0 or add 'MongoDB.Driver.Core' to the property 'SkippedInstrumentations' to suppress this error.

To resolve the error either add the recommended instrumentation library or skip the instrumentation of the listed package by adding it to the SkippedInstrumentation property, example:

<PropertyGroup>
   <SkippedInstrumentations>MongoDB.Driver.Core;StackExchange.Redis</SkippedInstrumentations>
</PropertyGroup>

The same property can be also specified directly via the CLI, notice that the separator, ;, needs to be properly escaped as ‘%3B’:

dotnet build -p:SkippedInstrumentations=StackExchange.Redis%3BMongoDB.Driver.Core

To distribute the appropriate native runtime components with your .NET application, specify a Runtime Identifier (RID) to build the application using dotnet build or dotnet publish. This might require choosing between distributing a self-contained or a framework-dependent application. Both types are compatible with automatic instrumentation.

Use the script in the output folder of the build to launch the application with automatic instrumentation activated.

• On Windows, use instrument.cmd <application_executable>
• On Linux or Unix, use instrument.sh <application_executable>

If you launch the application using the dotnet CLI, add dotnet after the script.

• On Windows, use instrument.cmd dotnet <application>
• On Linux and Unix, use instrument.sh dotnet <application>

The script passes to the application all the command-line parameters you provide.