How to use Resource Detector for GCP

[cybodelic]

Hi, i'm wondering how to use the resource detector for GCP. I'm running a service on Google Kubernetes Engine but don't see any specific resource labels like pod name or so in Google Trace, only the projectId (not sure if this is GCP specific). I guess opentelemetry-resource-detector-gcp should do what i need but unfortunately the usage section in the readme is still TODO. Simply adding the dependency does not work. Anyone can help?

[weyert]

You should be able to use detectResources and then pass it via the detectors-property on the config object. This wil return a new Resource-instance that you can pass to your trace provider

// pseudo code (not error free)
import { detectResources } from '@opentelemetry/resources';
import { gcpDetector } from '@opentelemetry/resource-detector-gcp'
const resource = await detectResources({
   detectors: [gcpDetector],
})

const tracerProvider = new NodeTracerProvider({ resource });

[cybodelic]

Hi, thanks for the response. detectResources is async therefore the tracing config has to be placed inside an async block as well. But that means it no longer would be guaranteed that module instrumentation is done before modules are loaded so i assume this approach is not recommended. Anyway I've tried it (using an async iife) and get an error:

(node:1) UnhandledPromiseRejectionWarning: Error: Could not load the default credentials.
Browse to https://cloud.google.com/docs/authentication/getting-started for more information.

Any other suggestions?

[weyert]

Are you running it locally? If so, you might need to run gcloud auth login

[cybodelic]

It's running on a GKE cluster. Without the detectResources call the credentials are successfully fetched from the metadata server and tracing works