Setting up .NET tracing on Kubernetes

The Instana AutoTrace webhook is an implementation of a Kubernetes Mutating Webhook Admission Controller. It automatically sets up everything that is required to monitor .NET applications with Instana across an entire Kubernetes cluster.

If the Instana AutoTrace webhook is installed on the Kubernetes cluster, tracing is automatically enabled for the .NET applications that run in those clusters.

To enable the Instana AutoTrace webhook, complete the following steps:

1. Install the Instana agent on Kubernetes. See Installing the Instana agent on Kubernetes.

2. Install the Instana AutoTrace webhook on Kubernetes clusters by using Helm. Ensure that .NET Core tracing is enabled during installation:

   --set autotrace.instrumentation.manual.netcore=true

   For more information, see Installing AutoTrace webhook.

   Note: If .NET Core tracing is enabled, do not disable the other tracers (Python, Node.js, and Ruby). Disabling these tracers might affect the .NET Core tracing function.

3. If you want to selectively enable tracing for specific applications, you can use the opt-in mode:

   1. Enable an opt-in mode during AutoTrace webhook installation:

      --set autotrace.opt_in=true

   2. Add the instana-autotrace: "true" label to the resources that you want to instrument. You can add this label at the required pods, replica sets, stateful sets, daemon sets, and deployments. If you want to exclude it from instrumentation, set instana-autotrace: "false".
4. Deploy and run your application.

The AutoTrace webhook automatically injects the required environment variables and instrumentation into your .NET application pods.

If you prefer not to use the AutoTrace webhook or need more control over the setup, you can manually configure tracing by adding environment variables to your deployment.

To enable tracing manually for a .NET Core application on Kubernetes, complete the following steps:

1. Install the following NuGet packages in your application:

   • Instana.Tracing.Core
   • Instana.Tracing.Core.Rewriter.Linux

   When the packages are distributed through NuGet.org, you can install them without recompiling the application. Use one of the following methods:

   • nuget.exe available: Restore the packages by using nuget.exe without compiling the project that is to be instrumented.
   • nuget.exe unavailable: Download the packages directly, extract them, and then set the environment variables to point to the extracted files as described in the following step.

2. Add the following environment variables to your Kubernetes deployment YAML:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: my-dotnet-app
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: my-dotnet-app
     template:
       metadata:
         labels:
           app: my-dotnet-app
       spec:
         containers:
         - name: my-dotnet-app
           image: my-dotnet-app:latest
           env:
           - name: DOTNET_STARTUP_HOOKS
             value: "[path-to-your-app]/Instana.Tracing.Core.dll"
           - name: CORECLR_ENABLE_PROFILING
             value: "1"
           - name: CORECLR_PROFILER
             value: "{cf0d821e-299b-5307-a3d8-b283c03916dd}"
           - name: CORECLR_PROFILER_PATH
             value: "[Path_to_your_app]/instana_tracing/CoreProfiler.so"
           - name: INSTANA_AGENT_HOST
             valueFrom:
               fieldRef:
                 fieldPath: status.hostIP
           - name: INSTANA_AGENT_PORT
             value: "42699"

   Replace [path-to-your-app] with the actual paths to your application directory.

3. Deploy and run your application.