If you’re already using OpenTelemetry, or you’ve decided to instrument your code with OpenTelemetry’s SDKs, you need to tell the SDKs where to send the telemetry data.
Before beginning this guide, you should have:
Now that you have a telemetry pipeline in your cluster, you must configure the SDKs to forward the telemetry data to your Collectors. To do this, you will use the Kubernetes Downward API, which allows you to pass information about the wider context of your Kubernetes environment into your deployments and therefore your pods. For example, you can use the Downward API to add environment variables that can store pieces of metadata, like the Cluster name.
In our Kubernetes Quick Start, you deployed a DaemonSet-mode Collector listening on the IP address of the node, which is where your SDK must send telemetry data.
Using the Downward API, create an environment variable and pass in the node’s IP address:
env: - name: NODE_IP valueFrom: fieldRef: fieldPath: status.hostIP
Configure the node’s environment variable name and value. In this example, we use .NET’s standard environment variable, which is named
OTEL_EXPORTER_OTLP_ENDPOINT, and set it to the value of the node’s IP address.
env: - name: NODE_IP valueFrom: fieldRef: fieldPath: status.hostIP - name: OTEL_EXPORTER_OTLP_ENDPOINT value: http://$(NODE_IP):4317
After a few minutes, data should start flowing through your observability pipeline and into Honeycomb.